Opisywanie wartości odżywczej produktów w celu kupowania i spożywania zdrowszej żywności oraz napojów bezalkoholowych
Referencias
References to studies included in this review
References to studies excluded from this review
References to ongoing studies
Additional references
References to other published versions of this review
Characteristics of studies
Characteristics of included studies [ordered by study ID]
| Study characteristics | ||
| Methods | Setting: one public coffee shop on a large academic hospital site, UK Design: quasi‐randomised controlled trial Recruitment: all coffee shop customers during the study period were participants Allocation to group: sign display (or absence thereof) was allocated by week using sealed envelopes | |
| Participants | General customers (primarily healthcare workers and university staff) | |
| Interventions | Intervention: point‐of‐purchase signs indicating the energy content of every drink and snack (6 weeks) Control: no point‐of‐purchase signs (6 weeks) | |
| Outcomes | Sales of high energy snacks and drinks (presented as a proportion) | |
| Notes | The intervention signs were displayed for 6 randomly allocated weeks over a 12‐week period. The final allocation sequence was: C‐C‐I‐C‐I‐I‐C‐C‐I‐C‐I‐I. The number of items purchased during the study period was 20,516. This study was funded by the Scottish Government's Chief Scientist's Office | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Sign display (or absence thereof) was randomised by week. 12 envelopes containing the instructions 'I' or 'C' were selected at random by an independent observer |
| Allocation concealment (selection bias) | Low risk | Envelopes were sealed (no other information was reported) |
| Blinding of participants and personnel (performance bias) | High risk | Given that intervention and comparison were in the same coffee shop, it is possible that customers, particularly repeat customers, would have observed that there was an intervention during the different weeks (not blinded) |
| Blinding of outcome assessment (detection bias) | Low risk | The outcome (proportion of high energy drinks and snacks purchased) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | All available data were collected and analysed |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Unclear risk | Sample sizes for the intervention and control weeks were not reported (i.e. it is not clear if participant outcomes vary across the weeks of the study) |
| Study characteristics | ||
| Methods | Setting: major grocery store chain in a large city, USA Design: interrupted time series Recruitment: existing sales data Allocation to intervention: naturally occurring pre‐ and post‐Nutrition Labelling Education Act (NLEA, 1990) legislation | |
| Participants | General customers | |
| Interventions | Pre NLEA labelling: no enforced labelling (sample size not reported) NLEA* labelling: 'Nutrition Facts' panel on side or back of product with descriptors on front of pack (sample size not reported) *The NLEA regulations allowed a choice of several descriptions for a given nutrient such as 'low fat', 'reduced fat', 'light' Overall, 2684 item sales analysed | |
| Outcomes | Sales performance of different categories of food with various types of labels (obtained from electronic sales data) | |
| Notes | This study was conducted from 14 September 1989 to 14 May 1997, with data collected on a weekly basis. "Sales transactions were aggregated across stores to derive the weekly category share for the healthy [products] associated with a given nutrient", and then the authors conducted a regression analysis. Data on 'low‐calorie' bottled juices, 'light' frozen entrées, and 'light' frozen dinners (i.e. items deemed to be 'calorie healthy' by the study authors) were extracted from this study. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) | Low risk | The outcome (sales performance of different categories of labelled food) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Unclear risk | Details of incomplete outcome data are not presented; the authors stated that "we tried to analyse the data within the constraints imposed by the pervasive problem of missing data" |
| Selective reporting (reporting bias) | Unclear risk | The Methods section does not specify which categories of food were to be included in the analysis |
| Was the intervention independent of other changes? | High risk | The authors noted that "our models do not incorporate explanatory variables such as price or other type of deals", suggesting that other changes could have occurred during the study period |
| Was the shape of the intervention effect pre‐specified? | Low risk | A regression model compared pre‐intervention and the post‐intervention phase, with an exact date of intervention reported. The authors provided a hypotheses specifying the expected effect of the intervention |
| Was the intervention unlikely to affect data collection? | Low risk | Sources and methods of data collection were the same before and after the intervention: electronic sales data |
| Other bias | High risk | Data from a number of stores belonging to one grocery chain were included, but it is unclear how the stores were selected. The introduction of legislation may have drawn additional attention to signposting throughout the city, not just the stores in question (thus possibly introducing a co‐intervention) |
| Study characteristics | ||
| Methods | Setting: university campus buildings, USA Design: cluster‐randomised controlled trial (by vending machine) Recruitment: convenience sample Allocation to group: vending machines were randomly assigned but no information was reported on how this was achieved | |
| Participants | University students and staff members | |
| Interventions | Intervention 1: brightly coloured (colour not specified) shelf label (2 inch × 5 inch, or 5 cm × 12.5 cm) stating: "0 calorie, 0 carbs" (on water, diet and regular fizzy drinks) (n = 3 vending machines) Intervention 2: brightly coloured shelf label stating "0 calorie, 0 carbs" plus a motivational poster encouraging the purchase of water and non‐energy‐containing soft drinks (n = 3 vending machines) Control: vending machines in similar location to the intervention machines selling similar but unlabelled drinks (n = 2 vending machines) | |
| Outcomes | Sales of water, diet and regular fizzy drinks (soda) | |
| Notes | This study had a 2‐week baseline period, a 5‐week intervention period, and a 2‐week post‐intervention period. Results from intervention 2 did not meet inclusion criteria for this review so were not included. Data on sales of diet soda extracted from this study. This project was funded in part by the Dorothy Epstein Nutrition Fellows award | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that "the vending machines were randomly assigned to one of three conditions" |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | High risk | Given that intervention and comparison machines were on the same university campus, it is possible that participants would have observed that there were different labels at different machines (not blinded) |
| Blinding of outcome assessment (detection bias) | Low risk | The outcome (mean number of drinks sold) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | It appears that all available data were collected and analysed: "the totals of each type of beverage sold and machine revenue were electronically tracked at each location at the end of each period" |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | High risk | The mean number of drinks sold at baseline from comparison vending machines was substantially lower than in the intervention vending machine |
| Study characteristics | ||
| Methods | Setting: 222 New York City (NYC) Starbucks coffee shops before‐and‐after NYC energy labelling legislation and 94 comparison stores in Boston and Philadelphia, USA Design: controlled before‐and‐after study (treated as an ITS as data were collected from multiple time points before and after the intervention) Recruitment: convenience sample of Starbucks customers Allocation to group: naturally occurring NYC legislation with Boston and Philadelphia as comparisons | |
| Participants | Customers at Starbucks coffee shops | |
| Interventions | Intervention: energy (kcal) information on menus and menu boards in a font and format that was at least as prominent as price (sample size not reported) Control: no energy information on menus and menu boards (sample size not reported) | |
| Outcomes | Energy (kcal) from food and drinks per transaction, obtained from electronic sales data and 'Starbucks card' holder data | |
| Notes | The authors collected data for all transactions "for a period of time 3 months before and 11 months after energy posting commenced (i.e., January 1, 2008–February 28, 2009). There are over 100 million transactions in the data set." The data were analysed by the authors using regression analysis. Figure 1 in the paper also presents the time series data in graphical form for food and drinks separately. We extracted regression information on combined data for food and drinks. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) | Low risk | The outcome (mean kcal per transaction) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | Given that the authors observed "every transaction at Starbucks company stores in NYC from January 1, 2008 to February 28, 2009", it appears that the data set are complete |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Was the intervention independent of other changes? | Low risk | The authors did not mention if any other historic events occurred during the study period, but they addressed other potentially confounding variables in regression analyses, including seasonality, day‐of‐week, holiday times, and climate. In addition, "to control for other factors affecting transactions, [the authors] also observe every transaction at Starbucks company stores in Boston and Philadelphia, where there was no calorie posting" |
| Was the shape of the intervention effect pre‐specified? | Low risk | A regression model compared pre‐intervention and the post‐intervention phase, with an exact date of intervention reported |
| Was the intervention unlikely to affect data collection? | Low risk | Sources and methods of data collection were the same before and after the intervention: electronic sales data |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university campus, USA Design: randomised controlled trial Recruitment: recruited through an introductory psychology course; participants received a course credit for participation Allocation to groups: no information on sequence generation was reported (the authors only stated that they used a 2 × 2 × 3 between subjects design) | |
| Participants | 188 female undergraduate students, overall mean age not reported; 70.7% were Caucasian (understood to be white), 15.4% African‐American and 13.9% Asian | |
| Interventions | Intervention 1: Kashi logo (a brand associated with 'healthful' eating) and a nutrition facts label with low energy (kcal) information (i.e. 130 kcal – the actual amount of kcal in each cookie) (n = 31) Intervention 2: Kashi logo and nutrition facts label with high energy (kcal) information (i.e. 260 kcal – twice the actual amount of kcal in each cookie) (n = 32) Control 1: Kashi logo and no nutrition facts label (n = 31) Intervention 3: Nabisco logo (a brand associated with 'unhealthful' eating) and nutrition facts label with low energy (kcal) information (i.e. 130 kcal – the actual amount of kcal in each cookie) (n = 31) Intervention 4: Nabisco logo and nutrition facts label with high energy (kcal) information (i.e. 260 kcal – twice the actual amount of kcal in each cookie) (n = 32) Control 2: Nabisco logo and no nutrition facts label (n = 31) | |
| Outcomes | Mean grams consumed assessed by weighing the portion served and portion remaining | |
| Notes | Each participant was given three oatmeal and dark chocolate chip cookies, each of which was broken in half (i.e. all participants actually received a Kashi cookie that was 130 kcal, even though some were labelled as Nabisco cookies). In a post hoc analysis by the study authors, data were combined for intervention 1 and 3, and compared with combined control 1 and 2 (no label control groups). This is the data we have extracted for this review. Information on funding was not reported. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that "participants were ... randomly assigned to one of the two brand conditions and one of the three calorie information conditions before they arrived at the laboratory" |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | The participants were told that the purpose of the study was to examine taste‐perceptions in snack foods. Personnel are likely to have been aware of the different labels and which participants saw which labels |
| Blinding of outcome assessment (detection bias) | Low risk | The outcome (mean grams of cookies eaten) was objectively assessed, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | It appears that all participants were included in the analyses |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section. Additional post hoc analyses were also presented |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university dining centre, USA Design: interrupted time series Recruitment: convenience sample of customers Allocation to group: none, set periods for each intervention stage | |
| Participants | Customers (largely college students) at a university dining centre | |
| Interventions | Pre‐intervention: no energy information; entrée descriptions posted on a 31 inch × 37 inch (79 cm × 94 cm) board for a 14‐day period (n = 13,951 entrées sold) Intervention: information on energy, serving size, fat (grams), protein (grams) and carbs (grams) on a menu board (5 inch × 3 inch – or 12.7 × 7.6 cm – board) (n = 14,199 entrees sold) Post‐intervention: no energy information; entrée descriptions posted on 8.5 inch × 11 inch (21.6 cm × 27.9 cm) floor stand as typically in cafeteria before study (n = 14,020 entrées sold) | |
| Outcomes | Energy content of entrées sold per day (e.g. salads, soups, sandwiches, deli foods, pizza, and other hot entrées), assessed by electronically collected sales data, with nutritional content calculated using software | |
| Notes | 12 hot entrées were targeted in this study (not specified). It was conducted between 25 October and 8 December 2004. The study involved a 14‐day pre‐intervention period, a 14‐day intervention period, and a 13‐day postintervention period. Data points were reported for each day (41 days). The authors used 'piecewise' regression to "test differences in average daily energy content of entrées purchased by dining center patrons for pretreatment vs treatment period and treatment vs posttreatment period." Figure 1 in the paper also presents the time series data in graphical form. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) | Low risk | The outcome (mean energy content of the entrées purchased) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | There was no attrition |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Was the intervention independent of other changes? | Low risk | The authors stated that "there were no other dining centres in the campus offering nutrition information, no campus‐wide nutrition education promoting the use of nutrition labels was active at the time of the study, and there was no known extraneous event occurring at about same time that could have changed purchasing behaviour." |
| Was the shape of the intervention effect pre‐specified? | Low risk | A regression model compared the pre‐intervention and post‐intervention phases. The authors provided a hypotheses specifying the expected effect of the intervention |
| Was the intervention unlikely to affect data collection? | Low risk | Sources and methods of data collection were the same before and after the intervention: electronic sales data |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: 20 dining centres on a campus of Cornell University, USA Design: interrupted time series Recruitment: convenience sample of customers Allocation to group: none, set periods for intervention | |
| Participants | Customers at a university dining centre | |
| Interventions | Pre‐labelling: no nutritional labelling of pre‐packaged "Fresh‐Take" meals and snacks (sample size not reported) Labelling: 'Nutrition Facts' labels on pre‐packaged meals and snacks, including information on serving size, energy, energy from fat, total fat, saturated fat, transfat, total cholesterol, sodium, total carbohydrates (including dietary fibre and sugars), and protein (sample size not reported) | |
| Outcomes | Energy purchased per week assessed from electronically collected sales data | |
| Notes | 63 (unspecified) food items were labelled. This study was conducted for 3 semesters pre‐labelling (fall 2006, spring 2007 and fall 2007) and 3 semesters post‐labelling (spring 2008, fall 2008 and spring 2009). The final result was a 12‐week set of data for each semester (3 data points before and 3 date points after the intervention). "Mixed models were used to determine if there was a significant trend or a difference in the proportion of sales within the sample (the dependent variables) based on calories or fat." Figure 1 in the paper also presents the time series data in graphical form. The authors stated the study was supported by funds provided by DNS, Cornell University | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) | Low risk | The outcome (mean total kcal purchased) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | High risk | Sales data for locations unavailable at second time point excluded and not accounted for. Target items not available at all locations for the whole period (18/63; 28%) were also excluded from the analysis. No information was provided as to whether excluded locations were similar to included locations in terms of customer base and sales |
| Selective reporting (reporting bias) | High risk | Outcome data from some target items that were not available at all locations for the whole study period were excluded from the analysis |
| Was the intervention independent of other changes? | High risk | The authors noted that "with data observed over many weeks and at various locations, it was impossible to control for all external factors or events that might have occurred over the entire length of the study." |
| Was the shape of the intervention effect pre‐specified? | Low risk | The point of analysis is the point of intervention. The study was exploratory with no predictions as to the direction of the effect |
| Was the intervention unlikely to affect data collection? | Low risk | Sources and methods of data collection were the same before and after the intervention: electronic sales data |
| Other bias | Low risk | The authors noted that their analysis was "weakened by the lack of information about the changes in purchasing patterns and sales data among all available foods (labelling, non‐labelling, pre‐packaged, or customised) before and after the nutrition labels were added to our sample" |
| Study characteristics | ||
| Methods | Setting: a cinema in south London, UK Design: randomised controlled study Recruitment: on street recruitment by interviewers from a research agency Allocation to group: a random number generator was used to assign participants to condition | |
| Participants | 325 participants were randomised, of whom 38 were excluded 51% were aged 18‐34 years, 36% were male, 37% were weight concerned, and 50% were overweight or obese | |
| Interventions | Intervention 1: green 'low fat' label on the side of a bag of toffee or salted popcorn (n = 103) Intervention 2: red 'high fat' label on the side of a bag of toffee or salted popcorn (n = 96) The bags of popcorn were given to the participants as they entered the cinema Control: no label (n = 88) | |
| Outcomes | Popcorn consumption as an absolute objective measure of energy (kcal) | |
| Notes | Six sets of results were presented by the study authors (3 treatment conditions × 2 types of popcorn). In our meta‐analysis, data were extracted for red 'high fat' label vs no label (combining data on salted and toffee popcorn consumption). We also extracted data on the 'low fat label' vs no label to evaluate potential harm, as the popcorn (both salted and toffee) served in this cinema was considered to be a high‐fat snack food. Subgroup analyses were conducted by the study authors to explore impact of weight concern, body weight and social deprivation on the effect of labels on consumption. The study was funded by a National Institute for Health Research Postdoctoral Fellowship award | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Pre‐determined random number sequence. Participants were given study numbers on the basis of the order in which they arrived at the cinema |
| Allocation concealment (selection bias) | Low risk | Researchers giving out the cards with the study numbers did not know the randomisation for that number. Another researcher then allocated the participants to a group based on the number on their card |
| Blinding of participants and personnel (performance bias) | Low risk | Participants were not aware of the true purpose of the study, nor that researchers were going to assess their consumption. Study personnel were aware of allocation of participants when explaining the study. However, one of three researchers explained the intervention to each of the three groups, minimising the opportunity for one researcher to treat participants differently according to group. Additionally, the same script was used by all personnel regardless of which group they were dealing with |
| Blinding of outcome assessment (detection bias) | Low risk | Assessors were aware of group allocation when assessing energy consumption, but food intake measurement appears to have been objective (weight of popcorn left over from a serving), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | 325 participants were recruited, 38 (12%) of whom were excluded from the analyses of the effect of labelling on consumption due to multiple attendances (n = 14), not leaving their popcorn bags (n = 13) or for failure to consume any popcorn (n = 11) |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section. A protocol was provided by the lead author and the primary outcome reported (relevant to this systematic review) and is presented in the published paper |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: cafeteria located near a large medical centre and between a business area and middle‐class residential neighbourhood, USA Design: interrupted time series Recruitment: convenience sample; seated customers were approached and asked if they would be willing to answer a few questions about the foods they selected during peak Tuesday hours of 5.30‐7.30 pm Allocation to group: customer clusters of evening sessions, with each intervention having 3 sessions for a total of 15 sessions | |
| Participants | Cafeteria customers | |
| Interventions | Baseline: no labels (sample size not reported) Intervention: 'Lower calorie selection' labels on bright green paper with a bright red dot on the upper right‐hand corner and placed near food items (sample size not reported) 'Baseline 2': no labels (sample size not reported) | |
| Outcomes | The probability of choosing low energy food items (entrées, vegetables and salads) was assessed using electronic register sales data. Energy (kcal) content was calculated by the study authors using a caloric estimate list | |
| Notes | The authors stated that "purchases of more than 14,300 entrees, vegetables, and salads by 6,970 customers were unobtrusively monitored via the cash register inventory control system during 15 evening observations." (15 time points were reported). The authors stated that a "linear logistic regression analysis was used to compute chi‐square tests of the overall effects of labelling and food type (vegetable, salad, entrées) on the probability of choosing a low calorie food". Figure 1 in the paper also presents the time series data in graphical form. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) | Low risk | The outcome (probability of purchasing low energy items from each of three food categories) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | It appears that all observations were included in the analysis |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Was the intervention independent of other changes? | Unclear risk | No information was provided on confounding variables/historic events during the study period |
| Was the shape of the intervention effect pre‐specified? | Low risk | The point of analysis included the point of intervention |
| Was the intervention unlikely to affect data collection? | Low risk | The sources and methods of data collection were the same before and after the intervention: electronic data |
| Other bias | High risk | The data collection periods were very limited comprising 15 Tuesday evenings between 5.30 and 7.30 pm. Although the full opening hours and days for the cafeteria are not given, these periods may represent only a small proportion of the sales at the cafeteria |
| Study characteristics | ||
| Methods | Setting: university campus, USA Design: randomised controlled trial Recruitment: advertised as a market research study; participants received a course credit for participation Allocation to groups: no information on sequence generation was reported | |
| Participants | 175 female undergraduate students of the University of Hawaii, mean age 20.86 (4.32) years. 71.8% were in the normal weight range, 14.4% were overweight, 6.3% were obese, and 7.5% were underweight (BMI ≤ 18.5 kg/m²) | |
| Interventions | Intervention 1: label stating "new colours of low fat M&M's 240 calories, 1.69 oz [28.3 g], ~55 M&M's" (n = 47) Control 1: label stating "new colour of low fat M&M's" with no energy information (n = 49) Intervention 2: label stating "new colours of regular M&M's, 240 calories per serving, 1.69 oz [28.3 g], ~55 M&M's" (n = 41) Control 2: label stating "new colours of regular M&M's" with no energy information (n = 38) | |
| Outcomes | Energy (kcal) consumption assessed by weighing portion served and portion remaining and calculating energy contained in the portion consumed | |
| Notes | It is not clear how many sessions were conducted to complete this study, or where the study was conducted on campus. Data were extracted on intervention 2 vs control 2, and potential harms were considered by extracting data from control 1 (as M&M's were not actually low fat) vs control 2. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that participants "were randomly assigned to one of four experimental conditions." |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | Participants were told that the study was a taste‐rating exercise for market research and were thus unaware of the nature of the study. Personnel are likely to have been aware of the different labels and which participants saw which labels |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but food intake measurement appears to have been objective (weight of M&M's left over from a serving), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | High risk | Although 224 participants were recruited and participated, 175 (78%) were able to recall the label they saw and were included in the analysis. The rates of participants randomised to each group were not reported, so that attrition rates across groups are uncertain |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: a restaurant at Oklahoma State University campus, USA Design: randomised controlled study Recruitment: convenience sample of diners attending the restaurant Allocation to groups: the restaurant was split into three sections, each with a unique menu treatment. Upon arrival, a party of diners were randomly assigned to a table in one of the three sections | |
| Participants | Restaurant customers (N = 138 observations); 70% were aged 18‐34.9 years, 18% were aged 35‐54.9 years, and 12% were older than 55; 56% were female; 63% were university students; 44% had an annual income less than USD 25,000, 40% had an income between USD 25,000 and 99,999 | |
| Interventions | Intervention 1: menu with energy information (kcal) in parentheses before each item's price (n = 54) Intervention 2: menu with energy information (kcal) in parentheses before each item's price plus a green, yellow, or red traffic light symbol indicating specific energy level ranges (n = 54) Control: menu with no nutritional information (n = 30) | |
| Outcomes | Energy (kcal) purchased, calculated from receipts | |
| Notes | Diners could choose from 51 menu options including soups, salads, burgers, sandwiches, pasta, vegetarian dishes, meat dishes as well as deserts and drinks. Survey data were collected for 2 weeks during the 2010 fall semester. Data were combined for intervention 1 and intervention 2 and compared with the control. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | The authors only reported that "patrons were randomly assigned to one of three menu treatments" |
| Allocation concealment (selection bias) | Unclear risk | It is not clear who allocated the customers, or how allocation how participant allocation was concealed |
| Blinding of participants and personnel (performance bias) | Low risk | The authors stated that the diners were unaware their dining choices had been recorded, however, personnel working in the restaurant would know which section of the restaurant the diners were randomised to |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (energy (kcal) purchased, calculated from receipts collected by researchers), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Unclear risk | It is not stated how many were randomised ‐ only that there were 138 observations |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Unclear risk | Data were collected during a short observation period (2 weeks) |
| Study characteristics | ||
| Methods | Setting: a restaurant at the Oklahoma State University campus, USA Design: randomised controlled trial Recruitment: convenience sample of diners attending the restaurant Allocation to groups: the restaurant was split into three sections, each with a unique menu treatment. Upon arrival, a party of diners were randomly assigned to a table in one of the three sections | |
| Participants | Restaurant customers (N = 1532 usable observations); no participant characteristics were reported | |
| Interventions | Intervention 1: menu with energy information (kcal) in parentheses before each item's price (n = 469 usable observations) Intervention 2: menu with energy information (kcal) in parentheses before each item's price plus a green, yellow, or red traffic light symbol indicating specific energy level ranges (n = 591 usable observations) Control: menu with no nutritional information (n = 472 usable observations) | |
| Outcomes | Energy (kcal) purchased, calculated from receipts | |
| Notes | This study also included a price manipulation experiment; we extracted data reported over the entire experiment, including all observations regardless of the price of the food. Diners could choose from 51 menu options including soups, salads, burgers, pasta and meat dishes. Data were collected over a 19‐week period (August to November 2010). Data were combined for intervention 1 and intervention 2 and compared with the control. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | The authors only reported that "upon entering the restaurant, a lunch‐party was randomly assigned to one of three menu treatments." The authors noted that people assigned to the energy plus traffic light treatment group were in a section of the restaurant with booth seating, which some parties requested to have (so not all participants may have been randomised) |
| Allocation concealment (selection bias) | Unclear risk | It is not clear who allocated the customers, or how participant allocation was concealed |
| Blinding of participants and personnel (performance bias) | Low risk | The authors stated that the restaurant patrons were unaware of the study, and that waiting staff were instructed to refrain from telling diners about the study. Personnel working in the restaurant would know what section of the restaurant the diners were randomised to |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (energy (kcal) purchased, calculated from receipts collected by researchers), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Unclear risk | The total number of eligible observations was not reported, only that there were 1532 'usable' observations |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university laboratory, Canada Design: randomised controlled study Recruitment: students enrolled in introductory psychology who consented to participation in the study Allocation to groups: a random number generator was used to assign participants to condition | |
| Participants | Female psychology (university) students (n = 149). Mean age 19.11 (SD 1.82) years. 87 were restrained eaters and 62 were unrestrained eaters | |
| Interventions | Intervention 1: energy label on menu indicating low‐energy salad (600 kcal) and high‐energy pasta (1200 kcal) ‐ although both salad and pasta were 1200 kcal (n = 51) Intervention 2: energy label on menu indicating high‐energy salad (1200 kcal) and low‐energy pasta (600 kcal) ‐ although both salad and pasta were 1200 kcal (n = 47) Control: menu with no energy information (n = 49) | |
| Outcomes | Energy (kcal) consumed. No details were reported as to how these measurements were made | |
| Notes | The duration of study was not reported. Subgroup analysis was conducted by the study authors to explore the impact of the intervention in more and less restrained eaters. The Restraint Scale was used to categorise participants as restrained eaters (scoring 15 or higher) or unrestrained eaters (scoring below 15). Data from intervention 1 and 2 were extracted for those who chose pasta or salad when it was mislabelled as '600 kcal', and analysed together vs control to measure potential harm. Information on funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Random number generator used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Unclear risk | Participants were told that they would be rating a potential new menu item for a local restaurant. As this information was given to students in a psychology course by researchers, participants may have suspected that researchers were interested in some other outcome. Participants were debriefed to assess whether they guessed the nature of the study, but it is not clear what the outcome of this was |
| Blinding of outcome assessment (detection bias) | Unclear risk | No information reported on blinding or how outcome was assessed |
| Incomplete outcome data (attrition bias) | Low risk | Data incomplete, numbers reported in one table suggest two participants lost from the analyses, although this is a small number so unlikely to bias results |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university laboratory, Canada Design: randomised controlled trial Recruitment: students enrolled in introductory psychology who consented to participation in the study Allocation to groups: a random number generator was used to assign participants to condition | |
| Participants | Undergraduate students (n = 254) enrolled in the introductory psychology class. 138 (54%) females and 116 males (45.7%) Mean age of females was 18.69 (2.87) years and of males was 18.71 (1.79) years | |
| Interventions | Intervention 1: energy label on menu indicating low‐energy salad (400 kcal) and high‐energy pasta (1200 kcal) or high‐energy salad (1200 kcal) and low‐energy pasta (400 kcal) ‐ although both salad and pasta were 1200 kcal (n = 128) Intervention 2: energy label on menu indicating high‐energy salad (1200 kcal) and high‐energy pasta (1200 kcal) plus information on the recommended daily energy intake of 2000 kcal for women and 2400 kcal for men, presented at the bottom of the menu (n = 60) Control: menu with no energy information (n = 66) | |
| Outcomes | Energy consumed, with no detail as to how these measurements were made | |
| Notes | Duration of study was not reported. Subgroup analysis was conducted by the study authors to explore the impact of the intervention in more and less restrained eaters. The Restraint Scale was used to categorise participants as restrained eaters (scoring 15 or higher) or unrestrained eaters (scoring below 15). The effect of labelling on males and females also explored. Data were extracted for intervention 2 vs control. We did not include intervention 1 in this review as it involved mislabelling some of the foods, and data were not reported separately on consumption of foods that were accurately labelled and consumption of foods that were mislabelled. Information on study funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Random number generator used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Unclear risk | Participants were told that they would be rating a potential new menu item for a local restaurant. As this information was given to students in a psychology course by researchers, participants may have suspected that researchers were interested in some other outcome. Participants were debriefed to assess whether they guessed the nature of the study, but it is not clear what the outcome of this was |
| Blinding of outcome assessment (detection bias) | Unclear risk | No information reported on blinding or how outcome was assessed |
| Incomplete outcome data (attrition bias) | Low risk | No attrition evident from tables; all participants accounted for |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university laboratory, Canada Design: randomised controlled trial Recruitment: students enrolled in introductory psychology who consented to participation in the study Allocation to groups: a random number generator was used to assign participants to condition | |
| Participants | Undergraduate psychology students (n = 49 included in the analysis) | |
| Interventions | Intervention: foods (pizza, soup) presented with energy labels (n = 24) Control: foods (pizza, soup) presented without energy labels (n = 25) | |
| Outcomes | Energy (kcal) consumption | |
| Notes | Unpublished study; the authors provided study data. This study comprised six study groups with combinations of interventions in terms of labelling and ordering behaviour. Only two groups described above were eligible for inclusion in this review | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Random number generator used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Unclear risk | Not reported |
| Blinding of outcome assessment (detection bias) | Unclear risk | Not reported |
| Incomplete outcome data (attrition bias) | Low risk | Full data provided for all those allocated in intervention and comparison |
| Selective reporting (reporting bias) | Unclear risk | Not reported |
| Other bias | Unclear risk | Not enough methodological information was reported to asses if there were other potential sources of bias |
| Study characteristics | ||
| Methods | Setting: university, Canada Design: randomised controlled trial Recruitment: via newspaper, online and bus advertisements Allocation to group: no information on sequence generation was reported | |
| Participants | 666 adults from Ontario (Canada), of whom 31 were excluded. Of those included, 36% were aged 18‐34 years, 49% were aged 35‐65 years, and 15% were aged over 65. 71% were white and 17% had no more than high school education, 64% had a college or university education and 19% had postgraduate level education | |
| Interventions | Intervention 1: menu with energy information (kcal) (n = 165) Intervention 2: menu with energy (kcal) content using a traffic light format, indicating whether the energy content was high (red), medium (orange) or low (green) (n = 156) Intervention 3: menu with energy (kcal), fat, salt, and sugar information using a traffic light format for each item (n = 152) Control: menu with no nutritional information (n = 162) | |
| Outcomes | Consumption of energy (kcal), fat, salt and sugar assessed by weighing food served and food remaining after consumption and estimating energy and nutrients in what was consumed based on nutritional content of choices given by the retailer | |
| Notes | No detailed information regarding where the study took place (other than at a university), but it was a separate location from the fast food chain (Subway) where food was purchased on behalf of the participants. The study was conducted between November 2010 and June 2011. Data were combined for Interventions 1, 2 and 3, and compared with the control. This study was funded by a research grant from the Canadian Cancer Society Research Institute | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that "participants were randomised to receive one of four menus". One study menu was implemented on each evening that the study ran with the study menus being implemented on a recurring sequence from one to four. It is not stated whether participants were randomised to receive a particular menu (rather than to a particular evening) nor whether a random allocation sequence was used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | The authors stated that "participants were blinded to the study condition." There was no information on blinding of personnel; however it seems unlikely that they could be blinded from the knowledge of which intervention was being implemented on a given evening |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | 31/666 (5%) participants were excluded from the analysis: 26 for not ordering a meal and 5 for missing data or for failing to meet the study protocol (excluded participants were not reported by treatment group). This low exclusion rate was unlikely to have affected the results |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section. This study was registered with ClinicalTrials.gov (NCT01948752), and the outcomes reported are presented in the published paper |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: community‐conference rooms at local hotels and the basement of a church (settings where the experiment took place, but not part of the experiment per se), USA Design: randomised controlled trial Recruitment: advertisements in local newspapers and flyers in community locations and in person at high schools Allocation to groups: no information on sequence generation was reported | |
| Participants | Adolescents and adults recruited from suburban and urban populations in the local community including a high school whose students regularly ate fast food. Total number of participants recruited is not given although 605 participants completed the study procedures, of whom 301 were in the two study groups included in this review Age: 16‐25 years: 25% (n = 147); 26‐40 years: 19% (n = 115), 41‐60 years: 42% (n = 248); > 60 years: 14% (n = 84) Gender: male 41% (n = 241), female 59% (n = 353) Ethnicity: Hispanic/Latino 3% (n = 20); Non‐Hispanic/Latino, 97% (n = 567) | |
| Interventions | Intervention 1: menu with energy (kcal) information on a bright yellow background plus recommendation of daily energy intake for men and women in a box on the right‐hand bottom corner of the menu (n = 151) Intervention 2: menu with no energy label, but with value pricing (the unit cost decreases as portion size increases) (n = 143) Intervention 3: menu with energy (kcal) information plus recommendation of daily energy intake (as above) and value pricing (n = 150) Control: menu with no energy labelling and no value pricing (n = 150) | |
| Outcomes | Nutrient composition of meal purchased and consumed: absolute measure of the energy and nutritional content (fat, saturated fat, carbohydrate, protein, fibre, vitamin C and calcium) were calculated using a food composition table available from the McDonald's corporation in combination with the gram weight information for the amount of each food item selected and consumed | |
| Notes | Participants chose items available from a McDonalds lunch/dinner menu, and research staff drove to nearby McDonald's restaurant to purchase meals ordered by the participants. Study sessions were held on weekday and weekend evenings (4:50 pm to 7:30 pm) between October 2005 and April 2006. Subgroup analyses were conducted by the study authors for: men and women; those who reported seeing the intervention menus and those who did not; those who reported that nutrition was important to them and those who did not; and those who reported that price was important to them and those who did not. Information about randomisation and raw data for subgroup analyses requested, but no response from author. Data were extracted on intervention 1 vs control. Interventions 2 and 3, which involved a price component, were not eligible for inclusion in this review. The research was supported by a NIDDK grant | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that "a randomised controlled 2 × 2 factorial experiment was conducted...". |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | Participants were blinded to the purpose of the study through a cover story. At the end they were questioned to ascertain whether they had noticed the menu manipulations and ascertained the purpose of the study. There is no indication as to whether personnel were blinded to allocated intervention |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | 605 participants are reported to have completed the study procedures, and of these, 11 (1.8%) were excluded from the analysis because "they knew before participating in the study that calories might be listed or price would be modified on the menu, or knew that they would not have to pay for their meal." No information was reported regarding the number of participants who dropped out in each group. This low exclusion rate was unlikely to have affected the results |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: restaurant at a country club, USA Design: interrupted time series design Recruitment: all children's meals sold during study period were included in the analysis Allocation to groups: none, set periods for intervention | |
| Participants | Participants were those buying children's meals at the restaurant of a family‐oriented private club | |
| Interventions | Intervention 1: menu with energy (kcal) and fat (gram) information (sample size not reported). Intervention 2: healthy (apple) symbol on menu to denote 'healthier' choices (sample size not reported). Intervention 3: Nutrition Bargain Price (NBP) on menu. "The NBP equals the monetary price divided by a nutrition scaling factor (completeness score). By adjusting the price by nutritional quality, a more immediate indicator of the nutritional cost/reward of the combination, is provided." (sample size not reported) Control: no nutritional information on menu (sample size not reported) Overall, 1275 meals analysed | |
| Outcomes | Changes in purchasing of energy and fat in children's meals as a consequence of nutritional labelling | |
| Notes | The study was conducted from October 2010 to May 2011 with two month pre‐intervention and two month post‐intervention periods. Patrons could buy combo meals, such as chicken and fries, mini cheese pizza and fruit salad, grilled cheese and potato chips, spaghetti and fresh fruit, hotdog and applesauce, or a corn dog with carrots and celery ‐ or an a la carte menu including a peanut butter and jelly sandwich, spaghetti with butter or a cheeseburger, with the following sides: pretzels or celery and peanut butter. The authors conducted regression analysis, with corrections to account for sales from repeat customers, and the likely correlation between such sales. Data were extracted on intervention 1 vs control. Interventions 2 and 3 were not eligible for inclusion in this review. Funding was received from the Virginia Tech College of Agriculture and Life Sciences | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) | Low risk | The outcome (total energy and fat selected by families) was objectively obtained from electronic data, so that blinding of outcome assessment was not applicable in this study |
| Incomplete outcome data (attrition bias) | Low risk | It appears that all observations were included in the analysis |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Was the intervention independent of other changes? | Unclear risk | No information was provided on confounding variables/historic events during the study period |
| Was the shape of the intervention effect pre‐specified? | Low risk | The point of analysis included the point of intervention |
| Was the intervention unlikely to affect data collection? | Low risk | The sources and methods of data collection were the same before and after the intervention: electronic data |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: 2 private dining rooms located within a university, USA Design: randomised controlled study Recruitment: via word of mouth, flyers placed around the university campus, university newsletter Allocation: no information on sequence generation was reported | |
| Participants | Customers attending a dining room who were between 18 and 30 years of age. Demographic information for the total sample is not reported, but the percentage of females across the group varied between 54% and 57%, between 85% and 95% were white and between 74% and 79% were college students | |
| Interventions | Intervention 1: menu with energy (kcal) information plus information on recommended daily energy intake for women and men (n = 99) Intervention 2: each menu item presented with the number of minutes brisk walking required to burn off the energy in the item (n = 102) Control: menu with no energy information (n = 99) | |
| Outcomes | Energy consumed during the meal assessed by weighing the food served before and after consumption | |
| Notes | All menus contained the same fast food and beverage options including burgers, salads, a chicken sandwich, chicken nuggets, chicken strips, french fries, desserts, condiments, water, and a choice of sodas. The study was conducted from January to June 2012. Data were extracted on Intervention 1 vs control. Intervention 2 was not eligible for inclusion in this review as it did not present data on nutrient content. The study was partly supported by a Graduate Senate grant from the university | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Random number generator used to generate stratified randomisation sequence (author communication) |
| Allocation concealment (selection bias) | Unclear risk | It is not clear whether the random sequence was concealed from personnel |
| Blinding of participants and personnel (performance bias) | Low risk | The authors stated that participants were blinded to the study purpose. It is not stated whether the personnel would have known the group to which participants were randomised, but it would seem likely as they would see the menu given to each participant and so would be aware of how these varied |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | All 300 participants randomised completed the intervention and there is no indication of missing data for the outcome of interest in this review |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university campus laboratory, USA Design: quasi‐randomised controlled study Recruitment: campus newspaper Allocation to group: participants were assigned to groups based on the day of the week that they were available for their sessions | |
| Participants | 40 healthy weight women aged 18‐32 years | |
| Interventions | Intervention: label (110 mm × 120 mm), which was colour‐coded according to the level of energy density; the label included information on level of energy density (low, medium, or high), the actual value of energy density (1.25 kcal/g, 1.50 kcal/g, or 1.75 kcal/g), and the weight (g) and energy content per serving (n = 20) Control: no labels (n = 20) | |
| Outcomes | Daily energy intake from main entrées (breakfast, lunch and dinner); food was weighed to assess the consumption in grams and kJ | |
| Notes | Each meal included a main entrée, which was manipulated in energy density, and several low‐energy compulsory foods, which were standard in amount and type across all test sessions. Entrées consisted of an Apple Bake Crisp for breakfast, a pasta salad with yogurt dressing for lunch, and a pasta bake for dinner. The authors stated that "test sessions were scheduled on the same day of the week for four weeks." Subject group and condition of energy density (low, medium, high) were entered as fixed factors in the model, and subjects were treated as a random factor. In the meta‐analyses we entered the data assessing the effect of nutritional labelling on energy (kcal) consumption of a high‐energy meal. The study was supported by the National Institutes of Health grants | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Quasi‐randomised. Participants were assigned to one of two groups (information or no‐information group) based on the day of the week that they were available for their sessions |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | High risk | Thirteen subjects (65%) in the information group correctly discerned that the purpose of the study was to investigate the influence of energy density on the amount of food eaten – none guessed in control group |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | No dropouts during study, with 2 participants withdrawing before study started |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university conference room, USA Design: randomised controlled trial Recruitment: on a university campus through announcements in lectures and through electronic bulletin boards Allocation to groups: randomised using a random number generator | |
| Participants | Overweight or obese women (n = 62) Mean age: 21.87 (SD 3.03), range 18‐33 Ethnicity: 45.16% Hispanic or Latino; 27.42% Black/African American; 4.84% Caribbean non‐Hispanics; 8.06% Asian/Pacific Islander; 3.23% white Non‐Hispanic; 9.68% mixed race; 1.61% don't know/not sure Mean BMI: 28.42 kg/m² (SD 3.10) Education: 82% of all participants had a high school degree/equivalency, some college or a 2‐year college degree | |
| Interventions | Intervention 1: menu with energy (kcal) information (n = 20) Intervention 2: menu with energy (kcal) information and with exercise equivalents (n = 20) Control: menu with no energy information (n = 22) | |
| Outcomes | Energy (kcal) consumption during a meal; measured by weighing leftover food | |
| Notes | Food offered was fast food from Burger King. Participants attended twice for baseline and intervention meal. Subgroup analysis was conducted by the study author for restrained vs unrestrained eaters. A repeated measures analysis of variance was conducted. Data were combined from intervention 1 and 2 and compared with the control. This study was a thesis dissertation | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Random number generator used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | Participants were told that the study would assess factors influencing eating habits at fast food restaurants. Efforts were made to minimise contact between participants and thus the possibility of observation of differences in labelling provided. Researchers would have been aware of allocation when providing the menus |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | No evident attrition from cited participant numbers at both time points |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university classroom in a building not related to eating, USA Design: randomised controlled trial Recruitment: word of mouth, newspaper advertisements and Internet postings Allocation to groups: a random number generator produced randomisation lists stratified by sex | |
| Participants | Members of the general public in New Haven, Connecticut (n = 295) Female: 50% Mean age: 30.5 (SD 12.4) years Ethnicity: 54.6% white Education: 3.8% less than a high school education, 11.4% completed high school or general equivalency diploma (GED), 32.2% completed some college, 30.1% completed 4 years of college, and 22.5% had a graduate degree | |
| Interventions | Intervention 1: menu with energy (kcal) information in column to right of menu item (n = 97, n =92 included in the analysis) Intervention 2: menu with energy (kcal) information in column to right of menu item plus information about recommended daily energy intake given at the top of the menu: ''The recommended daily caloric intake for an average adult is 2000 calories'' (n = 110, n = 103 included in the analysis) Control: menu with no energy information (n = 96, n = 92 included in the analysis) | |
| Outcomes | Energy (kcal) consumed during a meal; objectively assessed using restaurant supplied information to assess energy content of meal ordered and then subtracting energy content of food remaining after the meal – where necessary weighing remaining portions | |
| Notes | Participants could choose items from menus from 2 restaurants (Au Bon Pain and a local, non‐chain restaurant). Menu items included all salads, dressings, sandwiches, wraps, and selected beverages and desserts from Au Bon Pain, and also mozzarella sticks, french fries, pizza, hamburgers, and cheesecake from the local restaurant. The study took place between June and August of 2009. Data were combined from intervention 1 and 2 and compared with the control. The study was funded by grants from the Rudd Foundation and the Robert Wood Johnson Foundation | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | A randomisation list was used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | The purpose of the study in investigating nutritional labelling was concealed from participants with a cover story. The different interventions were hidden from participants as the study took place in partitioned spaces. It is not clear if personnel were blinded |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | Low dropout with reasons given: 6/96 (6%) lost to follow‐up in no energy label group; 4/97 (4%) lost to follow‐up in energy label group; 9/110 (8%) lost to follow‐up in energy + information group. Of 303 randomised participants, 295 (97%) were included in the analysis |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university laboratory 'not affiliated with eating or weight research', USA Design: randomised controlled trial Recruitment: via flyers, word of mouth, and craigslist.com postings Allocation to groups: randomly generated allocation sequence, stratified by gender | |
| Participants | Members of the general public (n = 243) Mean age 26 (SD 10) years, range 18‐72 years, 63% female, 59% Caucasian (understood to be white), 22% Asian, 11% African‐American, 4% Hispanic, and 4% reported 'other' Mean BMI 23.2 (SD 4.52), 22% of sample obese Education: 42% had attended some college, 27% had a four year college degree, 22% had a graduate degree, 4% had a 2‐year college degree, 4% had a high school/GED degree only and 1% did not complete high school | |
| Interventions | Intervention 1: front‐of‐package standard smart choices label including a green check mark, the statement 'Smart Choices Program Guiding Food Choices,' and the information: "120 calories per serving and 11 servings per package" (n = 76 analysed) Intervention 2: front‐of‐package modified Smart Choices logo which included a green check mark, the statement 'Smart Choices Program Guiding Food Choices,' and the following information: "120 calories per 3/4 cup serving and 11 servings per package" (n = 71 analysed) Control: no label (n = 69 analysed) | |
| Outcomes | Grams of cereal and milk consumed; measured by weighing each participant's cereal box | |
| Notes | The participants were offered a breakfast cereal during the experiment. The study was conducted between August 2007 and August 2008. Data were combined from intervention 1 and 2 and compared with the control. The study was supported in part by funding from the Rudd Foundation | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Random number generator was used |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | Participants were told they would be taking part in a focus group about the cereal in front of them and would have a chance to eat the cereal (so blinded to the purpose of the study), but it is unclear whether personnel were blinded |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | 27/243 (11%) participants were excluded because they correctly identified that the study was testing the influence of nutrition information on their perceptions and/or behaviour. Data were not reported by group although the authors stated that the "proportion of individuals excluded did not differ significantly across study conditions (p = .451)" |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: university laboratory, USA Design: randomised controlled trial Recruitment: flyers posted on campuses Allocation to groups: no information on sequence generation was reported | |
| Participants | 47 participants, mean age 29.9 (SD 1.5) years, 23 males and 24 females, mean BMI 25.9 (SD 0.6) kg/m², 91% had completed some college education | |
| Interventions | Intervention: nutritional labels on foods based on US Department of Agriculture format (n = 23) Control: no label on food (n = 24) All participants also watched videos, either on how to read nutritional labels or about the organic food movement | |
| Outcomes | Energy (kcal) consumed during lunch; measured by weighing leftover food | |
| Notes | Participants were offered a buffet lunch (small salad bar, a sandwich bar, and side items including chips (crisps), chocolate bars, yogurt, fruit, water, soft drinks, white and chocolate milk, and juice). The study (involving single lunch sessions) was conducted between May and August 2009. Study data were obtained from the authors. The authors also conducted subgroup analyses for males and females. The study was funded by start‐up funds through the university | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that "participants were randomly assigned to one of two video groups ... and one of two labelling conditions." |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Low risk | Participants were told the purpose of the study was to explore the effect of labels and a video on consumption (so blinded to the purpose of the study). No information given to suggest whether or not personnel were blind to the intervention that participants received |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | No information to indicate that there was any data missing among those recruited |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: a large health care company, USA Design: randomised controlled trial Recruitment: e‐mail to randomly selected employees Allocation to groups: no information on sequence generation was reported | |
| Participants | 249 participants (employees) who placed 901 orders, mean age 40.6 (SD 11.09) years, 60% female, mean BMI 27.5 (SD 6.19) kg/m², 81% white | |
| Interventions | Intervention 1: traffic light labels on lunch menu items based on US Department of Agriculture guideline (n = 42) Intervention 2: energy (kcal) content on lunch menu items (n = 38) Intervention 3: energy (kcal) content and traffic light labels on lunch menu items (n = 46) Control: no label on lunch menu items (n = 123) | |
| Outcomes | Energy (kcal) ordered during lunch | |
| Notes | Participants were required to order an online meal for which they received a USD 3 discount on each lunch ordered throughout the study (up to 3 lunch orders per week). There were 13 different meal options including sandwiches with side dishes, wraps with side dishes, and entrée‐sized salads, as well as drinks (30 different options including sodas, juices, teas and water), snacks, and desserts (e.g. chips, fresh fruit, brownies). The study was conducted over 4 weeks. The authors also conducted regression analysis by BMI, males and females, and for 'non‐dieting' and 'dieting' individuals. Data were extracted for interventions 2 and 3 (combined) vs control. Intervention 1 was not eligible for inclusion in this review as it did not present data on nutrient content. Additional study data were obtained from the authors. The study was funded by one of the author's personal research funds | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported. The authors only stated that "we randomly assigned participants to one of these four menu conditions" |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) | Unclear risk | Not reported |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome was objective (food purchased), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | Data were reported for all participants randomised (those who placed at least one order appear to have been randomised) |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | Participants could make more than one order, so each outcome is not necessarily independent, which may inflate the SE estimate. The data received from the authors were adjusted for covariates |
| Study characteristics | ||
| Methods | Setting: cinema, the Netherlands Design: quasi‐randomised controlled trial Recruitment: announcements in local newspapers, radio, and on the Internet. Other recruitment methods included posting flyers in mailboxes and handing out flyers Allocation to group: allocated according to evening available | |
| Participants | 89 participants. Mean age of 50.44 (SD 12.35), 26.4% were male, 33% were overweight or obese, 50.5% had moderate educational level and 41.4% had high | |
| Interventions | Intervention: large poster with portion size and caloric guidelines for daily amounts (GDA) information on soft drinks (n = 48) Control: no label; different portion sizes for soft drinks were displayed indicating only the amount of millilitres that each cup contained (n = 41) | |
| Outcomes | Soft drink consumed (mL) during film was calculated by electronic weighing of leftovers | |
| Notes | Participants could choose between five portion sizes (200 mL, 250 mL, 400 mL, 500 mL and 750 mL cups). The study took place on two subsequent evenings during which participants could order free soft drinks. Authors were contacted to request information about the energy content of the soft drinks, but this information was not forthcoming. Information on study funding was not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Participants could select which of the two evenings they wanted to take part. On one of the evenings the intervention was implemented and the other evening was the control, but the participants were unaware of this when they chose when to participate |
| Allocation concealment (selection bias) | High risk | No allocation concealment |
| Blinding of participants and personnel (performance bias) | Low risk | Potential participants were told that a marketing study was conducted into consumers' attitudes towards cinemas (so blinded to the purpose of the study). Personnel would have been aware of which participants were in the intervention and comparison groups |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing food), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | No attrition apparent |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | High risk | Data were collected on only two subsequent evenings, and the sample size is relatively small |
| Study characteristics | ||
| Methods | Setting: university campus, USA Design: quasi‐randomised controlled trial Recruitment: new students and their families visiting a display as part of a university open house were approached by a research assistant asking them to take part | |
| Participants | 269 adults aged over 18 participated. Although further demographic information were collected, no information is given about sample demographics | |
| Interventions | Intervention: glass container labelled 'new low fat M&M's' (sample size not reported) Control: glass container labelled 'new colours of regular M&M's' (sample size not reported) | |
| Outcomes | Energy (kcal) consumed; assessed by weighing the serving of M&M's that participants had served themselves (97.3% were observed to eat all that they had served themselves) | |
| Notes | Participants helped themselves freely to M&M's in labelled glass containers. The study was conducted over 2 days. The authors stated that "no industry or government agency funds supported this project" | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Quasi‐randomisation based on the order in which people attended the open house |
| Allocation concealment (selection bias) | High risk | No allocation concealment |
| Blinding of participants and personnel (performance bias) | High risk | It is unclear whether participants would have been aware of the other group as both groups seem to have been running at the same time. The M&M's were unusual colours (gold, teal, purple and white), which could have affected consumption behaviour. Research assistants administering the study are likely to have been aware of the different interventions and who was receiving each |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing M&M's), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | Data seem to have been collected from all those who agreed to take part |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Low risk | No other potential threats to validity identified |
| Study characteristics | ||
| Methods | Setting: theatre located on a university campus, USA Design: quasi‐randomised controlled trial Recruitment: university students and staff at a large university campus recruited to be part of a study in which they would evaluate a pilot episode for a television show | |
| Participants | 179 participants; 49% males, mean age 28.7 years, mean BMI of 25.1 kg/m² with 110 normal‐weight and 69 in the overweight group | |
| Interventions | Intervention: each participant received 160 grams containing 640 kcal of granola in ziplock bags that had an 'attractive' 3.25 × 4 inch (8.26 cm × 10.2 cm) colour label: "Low‐Fat Rocky Mountain Granola" (sample size not reported) Control: as above but the granola was described as "Regular Rocky Mountain Granola". Below this, the label indicated, "Contains 1 Serving" or "Contains 2 Servings", or it provided no serving size information (sample size not reported) | |
| Outcomes | Energy (kcal) consumed; assessed by weighing of leftovers of granola | |
| Notes | The study was conducted over 10 sessions that lasted from 3:30 to 5:00 pm on each of 10 days (Tuesdays and Thursdays for 5 non‐consecutive weeks). The authors stated that "no industry or government agency funds supported this project" | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | By day of the week |
| Allocation concealment (selection bias) | High risk | No allocation concealment |
| Blinding of participants and personnel (performance bias) | Low risk | The study was also described as evaluating a pilot episode for a television show so there was a low risk of participants being aware of manipulation. Personnel are likely to have been aware of the different interventions and who was receiving each |
| Blinding of outcome assessment (detection bias) | Low risk | Not reported, but outcome seems to have been objective (weighing granola bag), so lack of blinding may not have influenced the results |
| Incomplete outcome data (attrition bias) | Low risk | 31/210 (15%) participants 'randomised' were not included in the analysis. Participants were excluded for not staying until the end of the show (n = 7), refusing to eat granola because of dietary restrictions or political principles (n = 4), spilling their granola on the floor (n = 3), emptying their granola bags into their pockets (n = 3), and failing to provide height and weight information (n = 14). Exclusions by treatment group were not reported |
| Selective reporting (reporting bias) | Low risk | All relevant outcomes reported in the Methods section are reported in the Results section |
| Other bias | Unclear risk | Not enough methodological information was reported to asses if there were other potential sources of bias |
BMI: body mass index; SD: standard deviation.
Characteristics of excluded studies [ordered by study ID]
| Study | Reason for exclusion |
| Intervention: included a leaflet, the effect of which could not be isolated from the labelling intervention | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites Outcome: purchasing not objectively assessed; participant self‐report used. Consumption only objectively assessed for intervention group, not for control group | |
| Study design: no no‐label control group; evaluates 2 different types of nutritional labelling schemes | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites | |
| Intervention: 4different types of nutritional labels which were not specific to a particular product but sugar sweetened beverages generally Control: no no‐label control group | |
| Outcome: no purchasing or consumption measured (portion size decisions) | |
| Intervention: labelling did not give information about specific nutrient content | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites | |
| Intervention: guiding stars labels that do not provide information about content of specific nutrients | |
| Study design: a quasi‐experimental single group, ITS study that did not meet the EPOC criteria of at least 3 data points before and after the intervention | |
| Study design: a quasi‐experimental single group, ITS study that did not meet the EPOC criteria of at least 3 data points before and after the intervention Control: there was no no‐labelling comparison as a nutrition facts label was already in operation in the cafeteria | |
| Intervention: consisted of 3 strategies, not just labelling alone (nutrition information, interpretive signage, and a promotional email) | |
| Outcome: buying intention (virtual web‐based supermarket where virtual purchases were evaluated) | |
| Study design: did not meet EPOC criteria for inclusion as an interrupted time series study | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites | |
| Study design: experimental design testing the effects of labelling and taxation Intervention: label did not provide information about content of specific nutrients or energy | |
| Study design: did not meet EPOC criteria for ITS: experiments 1 and 2: ITS design, only analysed using t‐tests/multiple regression controlling for background variables (e.g. time of day), but did not account for secular trends/autocorrelation (no data were presented in a graph which would allow re‐analysis) | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites Intervention: no attempt to separate out the impact of calorie information and need for physical activity. Outcome: self‐reported consumption of different foods and nutrients | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites | |
| Study design: ITS study that did not meet the EPOC criteria of at least 3 data points before and after the intervention | |
| Intervention: this study assessed different prices and calorie information treatment conditions, so that the impact of labelling alone could not be determined | |
| Intervention: multi‐component intervention of which nutritional labelling was only one part Outcome: self‐reported outcomes that were not objectively measured (participants were asked about foods and the number of times they had had them in the past 30 days) | |
| Intervention: hard‐to‐read vs easy‐to‐read nutrition labelling conditions Control: no no‐label control group Outcome: only purchase intention was assessed | |
| Outcome: participants did not pay money for items 'chosen' in the 'laboratory' grocery store | |
| Outcome: self‐reported choice of food assessed | |
| Study design: no no‐label control (4 different types of nutritional labels were assessed) Outcome: only purchase intention was assessed | |
| Intervention: evaluated a 'guiding stars' system (foods labelled with different star levels: 0 vs 1 vs 2 vs 3 stars) | |
| Study design: did not meet EPOC criteria for an ITS study | |
| Outcome: self‐reported measure of purchasing | |
| Study design: did not meet EPOC criteria for inclusion as a controlled before‐and‐after study | |
| Intervention: not possible to isolate the effect of labelling from other interventions | |
| Su: no no‐label control (study 1 and 2); evaluates 2 different types of nutritional labelling schemes | |
| Study design: pre‐post design that did not meet EPOC criteria for inclusion as an ITS study | |
| Study design: controlled pre‐post study with one intervention site and one control site Intervention: keyhole labelling that did not give information about the content of specific nutrients or energy | |
| Study design: the study did not meet EPOC criteria for inclusion as an ITS study | |
| Outcome: outcome appears to be hypothetical choice in different scenarios using an on‐line system (authors were contacted for more details, but no response provided) | |
| Potentially relevant study but not enough information in registry to assess. The study completion date is April 2015, but no associated publications are available. | |
| Outcome: 'At the end of the shopping session, the respondents proceed to the cashier but don't actually pay for their purchases.' | |
| Study design: pre‐post study not meeting EPOC criteria for inclusion as a controlled before‐and‐after study | |
| Study design: pre‐post study not meeting EPOC criteria for inclusion as an interrupted time series study | |
| Study design: did not meet EPOC criteria for inclusion as an interrupted time series study (not three pre intervention and three post‐intervention periods) | |
| Study design: pre‐post study that did not meet the EPOC criteria of at least 2 intervention and 2 control sites | |
| Study design: repeated measures design (all participant's received the control menu first followed by the experimental conditions which were presented in a randomised order) Outcome: only intention to purchase assessed | |
| Study design: pre‐post study that did not meet EPOC criteria for inclusion as an ITS study | |
| Study design: pre‐post study that did not meet EPOC criteria for inclusion as a controlled before‐and‐after study | |
| Study design: pre‐post study that did not meet EPOC criteria for inclusion as an ITS study | |
| Study design: pre‐post study that did not meet EPOC criteria for inclusion as an ITS study | |
| Study design: study that did not meet EPOC criteria for inclusion as an ITS study or as a controlled before‐and‐after study | |
| Intervention: the effect of labels could not be isolated from other interventions | |
| Intervention: labels did not meet inclusion criteria (coloured with no other information) | |
| Intervention: healthy menu items were presented on the menu alongside regular items but were labelled with a 'heart‐healthy' symbol only | |
| Outcome: self‐reported choice and consumption | |
| Intervention: label consisted of stars which give an indication of overall weighted content of different nutrients based on a summed score | |
| Intervention: the labelling intervention was associated with a 'taxing' intervention, so that the effect of labelling alone could not be isolated | |
| Intervention: labels did not provide information about actual nutritional content but were coloured to represent whether the foods were more or less healthy | |
| Intervention: labels did not contain information about specific nutrients or energy and their content in the product | |
| Intervention: all participants were exposed to traffic light labels; intervention group received financial incentives and control group did not | |
| Intervention: no no‐label control: red vs green traffic lights was the intervention (study 4) Outcome: rating the health quality of food (study 1 to 3) | |
| Study design: controlled before‐and‐after study that did not meet EPOC requirements for implementation in at least 2 intervention and 2 control sites (linked to Elbel 2011) | |
| Intervention: no no‐label control; evaluates 2 different types of nutritional labelling schemes | |
| Intervention: choices logo provided but information on specific nutrients were not provided | |
| Study design: a longitudinal analysis. The authors state that they presented weekly retail sales data and product feature records from 2001 to 2011, in order to analyse supply‐side changes in the market for margarine and spreads corresponding to implementation of the 2006 rule (although there is no clear graph showing sales through time that could be used as ITS data – just price or market share) | |
| Outcome: food preferences | |
| Study design: controlled before‐and‐after study but objective purchasing data (electronic till data) are only available for 1 intervention and 1 control store (so did not meet EPOC criteria with at least 2 intervention sites and 2 control sites) | |
| Intervention: intervention schools had both low‐fat labelling and parental information pamphlets; the effects of the 2 parts of the intervention could not be isolated |
EPOC: Cpchrane Effective Practice and Organisation of Care group; ITS: interrupted time series.
Characteristics of ongoing studies [ordered by study ID]
| Study name | The effects of four front‐of‐pack labelling schemes compared to standard Nutrition Information Panel, on mean nutrient profiling score of food purchases among the adult Australian consumers: a randomised trial |
| Methods | Randomised controlled trial |
| Participants |
|
| Interventions | The labelling schemes that will be tested in the study are:
|
| Outcomes | Healthiness of food purchases as evaluated by the mean nutrient profile score of all food and beverage products purchased over the four‐week intervention period. Mean nutrient profiling score will be calculated using the Food Standards Australia New Zealand (FSANZ) nutrient profiling standard. Food purchase information is collected via electronic records (participants will be asked to scan barcodes of purchased items and take photos of the till receipts using the smartphone app and send to the study investigators. The app will then transmit the data to study database. Participants will also be asked to send in the hard copies of their till receipts in a reply‐paid envelop provided by the study. Food purchase information will later be collated from both electronic and paper sources for analysis. |
| Starting date | 15 September 2014 |
| Contact information | Prof Bruce Neal The George Insitute for Global Health, Level 10, King George V Building, 83‐117 Missenden Rd, Camperdown NSW 2050 Australia Phone +61 299934558 |
| Notes | The study intervention includes 4 different front of pack nutrition labelling schemes that will be shown to study participants via a smartphone application. |
Data and analyses
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 1.1 Energy (kcal) of food purchased Show forest plot | 3 | 1877 | Mean Difference (IV, Random, 95% CI) | ‐46.72 [‐78.35, ‐15.10] |
| Analysis 1.1  Comparison 1: Labelling on menus vs no labelling in restaurants, Outcome 1: Energy (kcal) of food purchased | ||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 2.1 Energy (kcal) consumed during a meal Show forest plot | 8 | 1705 | Mean Difference (IV, Random, 95% CI) | ‐50.27 [‐104.41, 3.88] |
| Analysis 2.1  Comparison 2: Labelling on menus or placed on a range of food options vs no labelling in laboratory settings, Outcome 1: Energy (kcal) consumed during a meal | ||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 3.1 Energy (kcal) consumed during a meal Show forest plot | 3 | 547 | Mean Difference (IV, Random, 95% CI) | ‐72.04 [‐137.84, ‐6.25] |
| Analysis 3.1  Comparison 3: Labelling on menus vs no labelling in laboratory settings (studies with a low risk of bias), Outcome 1: Energy (kcal) consumed during a meal | ||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 4.1 Energy (kcal) consumption Show forest plot | 6 | 732 | Std. Mean Difference (IV, Random, 95% CI) | 0.05 [‐0.17, 0.27] |
| Analysis 4.1  Comparison 4: Labelling of a single food or drink option vs no labelling in laboratory settings, Outcome 1: Energy (kcal) consumption | ||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 5.1 Energy (kcal) consumption Show forest plot | 2 | 400 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.06 [‐0.26, 0.15] |
| Analysis 5.1  Comparison 5: Labelling of a single food or drink option vs no labelling in laboratory settings (studies at low risk of bias), Outcome 1: Energy (kcal) consumption | ||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 6.1 Energy (kcal) consumed during a meal Show forest plot | 2 | 267 | Mean Difference (IV, Random, 95% CI) | 15.48 [‐20.08, 51.04] |
| Analysis 6.1  Comparison 6: Consumption in laboratory settings: subgroup analysis by dietary restraint (studies providing a range of food options), Outcome 1: Energy (kcal) consumed during a meal | ||||
| 6.1.1 Restrained eaters | 2 | 129 | Mean Difference (IV, Random, 95% CI) | 20.87 [‐37.44, 79.18] |
| 6.1.2 Unrestrained eaters | 2 | 138 | Mean Difference (IV, Random, 95% CI) | 10.98 [‐38.85, 60.81] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 7.1 Energy (kcal) consumed during a snack Show forest plot | 1 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.17 [‐0.63, 0.28] | |
| Analysis 7.1  Comparison 7: Consumption in laboratory settings: subgroup analysis by dietary restraint (study providing a single food option), Outcome 1: Energy (kcal) consumed during a snack | ||||
| 7.1.1 Restrained eaters | 1 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.44 [‐0.94, 0.05] | |
| 7.1.2 Urestrained eaters | 1 | Std. Mean Difference (IV, Random, 95% CI) | 0.03 [‐0.34, 0.39] | |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 8.1 Energy (kcal) consumed during a snack/meal Show forest plot | 8 | 1705 | Mean Difference (IV, Random, 95% CI) | ‐50.28 [‐104.42, 3.87] |
| Analysis 8.1  Comparison 8: Consumption in laboratory settings: subgroup analysis by study country (studies providing a range of food options), Outcome 1: Energy (kcal) consumed during a snack/meal | ||||
| 8.1.1 Studies conducted in the USA | 5 | 895 | Mean Difference (IV, Random, 95% CI) | ‐70.57 [‐167.65, 26.52] |
| 8.1.2 Studies conducted in other countries | 3 | 810 | Mean Difference (IV, Random, 95% CI) | ‐58.18 [‐107.15, ‐9.21] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 9.1 Energy (kcal) consumed during a snack/meal Show forest plot | 6 | 732 | Std. Mean Difference (IV, Random, 95% CI) | 0.05 [‐0.17, 0.27] |
| Analysis 9.1  Comparison 9: Consumption in laboratory settings: subgroup analysis by study country (studies providing single food option), Outcome 1: Energy (kcal) consumed during a snack/meal | ||||
| 9.1.1 Studies conducted in the USA | 4 | 459 | Std. Mean Difference (IV, Random, 95% CI) | 0.14 [‐0.17, 0.45] |
| 9.1.2 Studies conducted in other countries | 2 | 273 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.12 [‐0.36, 0.11] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 10.1 Energy (kcal) consumed during a snack/meal in laboratory settings Show forest plot | 5 | 718 | Std. Mean Difference (IV, Random, 95% CI) | 0.19 [‐0.14, 0.51] |
| Analysis 10.1  Comparison 10: Low fat (or energy) labelling vs no labelling on high‐energy foods, Outcome 1: Energy (kcal) consumed during a snack/meal in laboratory settings | ||||
Examples of nutritional labels used in practice
Logic model of the process by which nutritional labelling may have an impact on diets and health
Study flow diagram
Risk of bias summary
Forest plot of comparison: Labelling on menus vs no labelling in restaurants, and energy (kcal) of food purchased
Forest plot of comparison: Labelling on menus or placed on a range of food options vs. no labelling in laboratory settings, and energy (kcal) consumed
Comparison 1: Labelling on menus vs no labelling in restaurants, Outcome 1: Energy (kcal) of food purchased
Comparison 2: Labelling on menus or placed on a range of food options vs no labelling in laboratory settings, Outcome 1: Energy (kcal) consumed during a meal
Comparison 3: Labelling on menus vs no labelling in laboratory settings (studies with a low risk of bias), Outcome 1: Energy (kcal) consumed during a meal
Comparison 4: Labelling of a single food or drink option vs no labelling in laboratory settings, Outcome 1: Energy (kcal) consumption
Comparison 5: Labelling of a single food or drink option vs no labelling in laboratory settings (studies at low risk of bias), Outcome 1: Energy (kcal) consumption
Comparison 6: Consumption in laboratory settings: subgroup analysis by dietary restraint (studies providing a range of food options), Outcome 1: Energy (kcal) consumed during a meal
Comparison 7: Consumption in laboratory settings: subgroup analysis by dietary restraint (study providing a single food option), Outcome 1: Energy (kcal) consumed during a snack
Comparison 8: Consumption in laboratory settings: subgroup analysis by study country (studies providing a range of food options), Outcome 1: Energy (kcal) consumed during a snack/meal
Comparison 9: Consumption in laboratory settings: subgroup analysis by study country (studies providing single food option), Outcome 1: Energy (kcal) consumed during a snack/meal
Comparison 10: Low fat (or energy) labelling vs no labelling on high‐energy foods, Outcome 1: Energy (kcal) consumed during a snack/meal in laboratory settings
| Nutritional labelling compared to no labelling for healthier food purchasing and consumption | ||||||
| Patient or population: university students/staff and general consumers | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect | № of participants | Quality of the evidence | Comments | |
|---|---|---|---|---|---|---|
| Risk with no labelling | Risk with nutritional labelling | |||||
| Food purchased from vending machines | Although more beverages were purchased in the labelling group, large baseline imbalances arising from a small number of randomised units meant that an accurate effect size could not be calculated. | — | (1 RCT) | ⊕⊝⊝⊝ | Sample size unknown (population purchasing from 3 intervention and 2 control public vending machines) | |
| Food purchased from a grocery store | Sales performance decreased after labelling was introduced in this interrupted time series study, although this was difficult to interpret because results were measured as health foods as a proportion of overall foods, rather than directly measuring the number of products purchased. | — | (1 ITS study) | ⊕⊝⊝⊝ | Sample size unknown (population purchasing from a large chain of grocery stores) | |
| Food purchased in restaurants (labels on menus) assessed with: kcal | The median food purchased in restaurants was 746 kcald | MD 46.72 kcal fewer (78.35 fewer to 15.10 fewer)e | — | 1877 | ⊕⊕⊝⊝ | Six additional studies (one Q‐RCT and 5 ITS studies which took place in a restaurant, cafeterias or coffee shops) also measured purchasing, 2 of which were ITS studies at low risk of bias (which assessed energy labels on menus/menu boards in a coffee shop or cafeteria) and found results consistent with this meta‐analysis. |
| Food consumed in laboratory settings (labels on menus or labels placed on a range of food options) | The median food consumed in laboratory settings was 796.4 kcald | MD 50.27 kcal fewer (104.41 fewer to 3.88 more) | — | 1705 | ⊕⊕⊝⊝ | — |
| Food consumed in laboratory settings (single snack food or drink option) | The median food consumed in laboratory settings was 316.975 kcald | SMD 0.05 (95% CI −0.17 to 0.27), P = 0.67 | — | 732 | ⊕⊕⊝⊝ | An SMD of 0.05 represents a small effect (Cohen 1988). |
| Potential harms (high‐energy snack foods consumed with misleading low fat/energy labels in laboratory settings) | The median food consumed with misleading low fat/energy labels in laboratory settings was 190 kcald | SMD of 0.19 (95% CI −0.14to 0.51), P = 0.25 | — | 831 | ⊕⊝⊝⊝ | An SMD of 0.19 represents a small effect (Cohen 1988). |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). | ||||||
| GRADE Working Group grades of evidence | ||||||
| aAll outcomes measuring immediate purchasing or consumption decisions at the point of exposure to the label, although returning customers in non‐laboratory settings may have experienced repeat exposure during the study period. | ||||||
| Reference and study design | Participants and Setting | Intervention/Comparison (sample sizes) | Outcome | Results | Summary effect |
|---|---|---|---|---|---|
| Cluster‐RCT | Students and employees at a university Real‐world setting | Brightly coloured '0 calories, 0 carbs' labels (n = 3 vending machines) vs no labels (n = 2 vending machines)a | Mean number of diet soda beverages (with '0 calories, 0 carbs') purchased from vending machines (weekly) | Mean 54.40 beverages (SD 16.69) vs 48.90 beverages (SD 1.84) | The methods used to analyse the data were not clearly reported and an accurate effect size and confidence intervals could not be calculated.b |
| aThe authors also evaluated another intervention ('0 calorie, 0 carbs' plus a motivational poster encouraging the purchase of water and non‐energy‐containing soft drinks) that was not eligible for inclusion in this review. | |||||
| Reference and study design | Participants and setting | Intervention/comparison (sample sizes) | Outcome | Results | Summary effect |
|---|---|---|---|---|---|
| Interrupted time series | Customers at a major grocery store chain Real‐world setting | 'Low calorie', 'diet' 'light' label on front of package vs no label (sample sizes not clear)a | Share (%) of sales of different food categories | "Regression models featuring calorie‐healthy foods consistently show [that] the relative sales performance of such items decreased after the onset of [mandatory labelling]": 'low calorie/diet/light' bottled juices = −1.538 (SE 0.191); 'light' frozen entrées = −2.601 (SE 0.373); 'light' frozen dinners = −4.507 (SE 0.963)b | Regression P values of < 0.001 indicated fewer foods with 'calorie healthy' descriptors were purchased. |
| aThe authors also evaluated 'vitamin C fortified' bottled juices, 'plus calcium/calcium added' juices, and 'low fat/reduced fat/fat free' cheese and cookies. These data were not eligible for inclusion in this review. | |||||
| Reference and study design | Participants and setting | Intervention/comparison (sample sizes) | Outcome | Results | Summary effect |
|---|---|---|---|---|---|
| Q‐RCT | Coffee shop customers at academic hospital Real‐world setting | Energy content of all food and drinks available on point of purchase signs vs. no information (N = 20,516 items purchased) | Proportion of high energy food and drinks purchased (as a percentage of total drinks and snacks sold) | The proportion of high energy snacks purchased was 41% in the intervention and 45% the control group (P = 0.04); the proportion of high energy drinks purchased was 46% in the intervention group and 50% in the control group (P = 0.15). | Effect size and confidence intervals could not be calculated. |
| Interrupted time series | Coffee shop customers Real‐world setting | Energy content on menu and menu boards vs no information (N = 118,480 transactions reported) | Mean kcal of food and drinks purchased per transaction | "Estimates of the effect of calorie posting (calories per transaction): log (beverages and food) = −0.060 (0.001)a–representing a ... decrease in average calories per transaction, equivalent to 14.4 calories" | Regression P value < 0.01 |
| Interrupted time series | Customers at a university dining centre Real‐world setting | Nutrition facts information on menu board (N = 14,199 entrées sold) vs no label (pre‐intervention: N = 13,951 entrées sold; post‐intervention N = 14,020 entrées sold) | Mean kcal content of entrées purchased per day | Mean energy content of entrées sold at start of the pre‐intervention period: 646.5 kcal with a slope of 0.094 kcal per day. The difference in energy content of entrées sold between the pre‐treatment last day and treatment first day was −12.4 kcal (P = 0.007). Following this reduction, the difference in slope pre‐intervention to intervention was −0.298 kcal per day, and the difference in slope intervention to post‐intervention was 1.512 kcal per day. This means that the average energy content of entrées purchased reduced immediately after the intervention, and gradually increased when the intervention was removed. | Regression P values were 0.56 (pre‐intervention to intervention slope), and 0.013 (intervention to post‐intervention slope). |
| Interrupted time series | Customers at a university dining centre Real‐world setting | Nutrition facts label on pre‐packaged meals and snacks vs no label (sample sizes not reported) | Mean kcal purchased per week from meals and snacks | "Mean [energy] purchased decreased significantly across the 3 [time points] of the pre‐labelling period. However, no such trend was observed in the post‐labelling period." (data compared over 3 time points)."After labelling, the mean energy content of the items purchased per week decreased significantly from 476.2 (SD 8.7) kcals to 445.3 (SD 8.1) kcals per week (p<0.001)." | A statistical comparison of time trends (i.e. slope) before and after the intervention was not reported, so that the overall effectiveness of the intervention is not clear. |
| Interrupted time series | Customers at a public cafeteria Real‐world setting | 'Lower calorie' label on green paper with a red dot on right‐hand corner beside food item vs no label (sample sizes of foods purchased is not clear) | Probability of choosing low energy entrées, vegetables, or salads | "The probability of choosing a low [energy] entrée did not differ from baseline." The probability of purchasing lower‐energy vegetables and salads significantly increased compared to the no label baseline conditions (P < 0.001). | A statistical comparison of time trends before and after the intervention was not clearly reported, so that the overall effectiveness of the intervention is not clear. |
| RCT | Customers at a restaurant Real‐world setting | 1. Energy content on menu (n = 54) 2. Menu with energy content using traffic light format (n = 54) 3. No label (n = 30) | Mean kcal purchased per meal (including entrées, desserts and drinks) | 756.5 kcal (SD 338.5)b vs 765 kcal (SD 368.0) | MD −8.50 kcal (95% CI −154.85 to 137.85) |
| RCT | Customers at a restaurant Real‐world setting | 1. Energy content on menu (n = 469) 2. Menu with energy content using traffic light format (n = 591) 3. No label (n = 472) | Mean kcal purchased per meal (entrées only) | 705.6 kcal (SD 334.7)c vs. 746 kcal (SD 368.0) | MD −40.38 kcal (95% CI −79.21 to −1.55) |
| Interrupted time series | Families at a restaurant Real‐world setting | Children's menu with energy and fat content label vs no label (N = 1275 meals)d | Mean kcal purchased per meal | "The calorie and fat menu had the biggest change in calories compared to the control menu (−9.54), but it was not significant." | A statistical comparison of time trends before and after the intervention was not reported, so that the overall effectiveness of the intervention is not clear. |
| RCT | Employees at large company buying lunch online Real‐world setting | 1. Energy content on menu (n = 38) 2. Menu with energy content using traffic light format (n = 46) 3. No label (n = 123)e | Mean kcal purchased per meal | 537.9 kcal (SD 203.9)f vs. 605.3 kcal (SD 222.5) | MD −67.38 kcal (95% CI −126.09 to −8.66) |
| aAccounting for effects of week, day of week and weather. | |||||
| Reference and study design | Participants and setting | Intervention/comparison (sample sizes) | Outcome | Results | Summary effect |
|---|---|---|---|---|---|
| Labelling on menus or placed on a range of food options on energy consumed during a meal | |||||
| RCT | University students Experimental (laboratory) study at a university | Energy content on menu plus information on recommended daily energy intake for women and men (n = 60) vs no label (n = 66)a | Mean kcal consumed during a meal (salad and pasta) | 608.2 kcal (SD 350.8)b vs 631.3 kcal (SD 324.0) | MD −23.02 kcal (95% CI −141.28 to 95.24) |
| RCT | University students Experimental (laboratory) study at a university | Energy content on menu (n = 24) vs no label (n = 25) | Mean kcal consumed during a meal | 433.1 kcal (SD 260.2) vs 426.5 kcal (SD 237.4)c | MD 6.60 kcal (95% CI −133.02 to 146.22) |
| RCT | Adults Experimental (laboratory) study at a university | 1. Energy content on menu (n = 165) 2. Menu with energy content using a traffic light format (n = 156) 3. Menu with energy, fat, salt, and sugar content using traffic light format (n = 152) vs no label (n = 162) | Mean kcal consumed during a fast food meal | 761.6 kcal (SD 348.9)d vs 839.6 kcal (SD 318.8) | MD −78.00 kcal (95% CI −136.29 to −19.70) |
| RCT | Adolescents and adults Experimental study conducted in hotel conference rooms/church hall | Energy content on menu plus information on recommended daily energy intake for women and men (n = 151) vs no label (n = 150)e | Mean kcal consumed during a fast food meal | 804.7 kcal (SD 423.9) vs 739.0 kcal (SD 358.2) | MD 65.70 kcal (95% CI −22.94 to 154.34) |
| RCT | Adults, including university students Experimental study at a university | Energy content on menu plus information on recommended daily energy intake for women and men (n = 99) vs no label (n = 99)f | Mean kcal consumed during a meal | 722.0 kcal (SD 271.6)g vs 770.0 (SD 269.1) | MD −48.00 kcal (95% CI −123.31 to 27.31) |
| RCT | Female university students Experimental (laboratory) study at a university | 1. Energy content on menu (n = 20) 2. Menu with energy content and exercise equivalents (n = 20) vs no label (n = 22) | Mean kcal consumed during a fast food meal | 870.1 kcal (SD 375.9)h vs 995.4 (SD 429.4) | MD −125.33 kcal (95% CI −339.26 to 88.59) |
| RCT | Adults from the community Experimental (classroom) study at a university | 1. Energy content on menu (n = 92) 2. Menu with energy content plus information on recommended daily intake (n = 103) vs no label (n = 92) | Mean kcal consumed during a meal | 1293.3 kcal (SD 656.8)i vs 1458.9 kcal (SD 724.6) | MD −165.58 kcal (95% CI −340.01 to 8.84) |
| RCT | Adults Experimental (laboratory) study at a university | Nutrition facts label on foods (n = 23) vs no label (n = 24) | Mean kcal consumed during a meal | 620.4 kcal (SD 203.6) vs 822.8 kcal (SD 408.7)j | MD −202.40 kcal (SD −385.86 to −18.94) |
| Labelling of a single food or drink option on energy consumed during a snack or meal | |||||
| RCT | Female university students Experimental (laboratory) study at a university | Energy label on chocolate cookie (130 kcal) (n = 62) vs no label (n = 62)k | Mean grams consumed from snack of chocolate chip cookies | 45.1 g (SD 21.50) vs 33.1 g (SD 21.57)l | SMD 0.55 (95% CI 0.19 to 0.91) |
| RCT | Adults Experimental study at a cinema | Red 'high fat' label on side of popcorn container (n = 96) vs no label (n = 88)m | Mean kcal consumed from snack of toffee or salted popcorn (high‐fat snack) | 413.5 kcal (SD 307.6)n vs 468.1 kcal (SD 361.9) | SMD −0.16 (95% CI −0.45 to 0.13) |
| RCT | Female university students Experimental study at a university | Energy label ('new colours of regular M&M's, 240 calories per serving"') on glass container containing M&M's (n = 41) vs no energy content label ('new colours of regular M&M's') (n = 38)o | Mean kcal consumed during snack of M&M's (high‐fat snack) | 157.2 kcal (SD 98.5) vs165.9 kcal (SD 141.5) | SMD −0.07 (95% CI −0.51 to 0.37) |
| Q‐RCT | Females Experimental (laboratory) study at a university | Energy label plus 'colour‐coded' information on level of energy density on an entrée (n = 20) vs no label (n = 20) | Mean kcal consumed from an entrée at breakfast, lunch and dinner | 1534.0 kcal (SD 451.7) vs 1569.0 kcal (SD 335.4) | SMD −0.09 (95% CI −0.71 to 0.53) |
| RCT | Adults Experimental (laboratory) study at a university | 1. Smart choices label on cereal box (n = 76 analysed) 2. Modified smart choices label (n = 71) vs no label (n = 69) | Mean grams of high‐sugar breakfast cereal and milk consumed | 225.7 g (SD 138.2)p vs 219.9 g (SD 127.1) | SMD 0.04 (95% CI −0.24 to 0.33) |
| Q‐RCT | Adults Experimental study at a cinema | Portion size and energy content label (display board) (n = 48) vs no label (n = 41) | Mean millilitres of soft drink consumed | 376.3 mL (SD 125.4) vs 382.14 mL (SD 147.6)q | SMD −0.04 (95% CI−0.46 to 0.37) |
| aTwo other interventions were combined by the study authors as a 'calorie only' intervention (400 kcal salad and 1200 kcal pasta, and 1200 kcal salad and 400 kcal pasta (although both salad and pasta contained 1200 kcal)). We did not include this data in the above analysis as it involved mislabelling some of the foods (data were not reported separately for consumption of foods that were accurately labelled). | |||||
| Reference and study design | Participants and setting | Intervention/comparison (sample sizes) | Outcome | Results | Summary effect |
|---|---|---|---|---|---|
| RCT | Adults Experimental study at a cinema | Green 'low fat' label on side of container containing high‐fat popcorn (n = 103) vs no label (n = 88) | Mean kcal consumed from snack of popcorn | 402.44 kcal (SD 288.68) vs 468.07 kcal (SD 361.93) | SMD −0.20 (95% CI −0.48 to 0.08) |
| RCT | Female university students Experimental study at a university | Low fat label ('new low fat M&M's') on glass container containing M&M's (n = 49) vs no energy information label ('new colours of regular M&M's') (n = 38) | Mean kcal consumed during snack of M&M's | 192.34 kcal (SD 145.53) vs165.88 kcal (SD 141.5) | SMD 0.18 (95% CI−0.25 to 0.61) |
| RCT | Female university students Experimental (laboratory) study at a university | Lower energy label (600 kcal) on high‐energy salad and pasta (actually 1200 kcal) (n = 56) vs no label (n = 49)a | Mean kcal consumed during a meal (salad and pasta) | 400.26 kcal (SD 199.8) vs 420.19 kcal (SD 233.69) | SMD −0.09 (95% CI −0.47 to 0.29) |
| Q‐RCT | Students and their families Experimental study at a university | Low fat label ('new low fat M&M's') on glass container containing M&M's vs no energy information label ('new colours of regular M&M's') (n = 269 overall (n by group not reported)) | Mean kcal consumed from snack of M&M's | Mean 244 kcal (SD not reported) vs 190 kcal (SD not reported) | SMD 0.44 (95% CI 0.20 to 0.68)b |
| Q‐RCT | University staff, graduates and undergraduates Experimental study at a university | Low fat label ('Low‐Fat Rocky Mountain Granola') on zip lock bag vs no label ('Regular Rocky Mountain Granola') (n = 66 overall (n by group not reported)) | Mean kcal consumed from snack of granola | Mean 249 kcal (SD not reported) vs 165 kcal (SD not reported) | SMD 0.69 (95% CI 0.20 to 1.18)c |
| aData were extracted for those who chose pasta or salad when it was inaccurately as '600 calories'. | |||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 1.1 Energy (kcal) of food purchased Show forest plot | 3 | 1877 | Mean Difference (IV, Random, 95% CI) | ‐46.72 [‐78.35, ‐15.10] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 2.1 Energy (kcal) consumed during a meal Show forest plot | 8 | 1705 | Mean Difference (IV, Random, 95% CI) | ‐50.27 [‐104.41, 3.88] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 3.1 Energy (kcal) consumed during a meal Show forest plot | 3 | 547 | Mean Difference (IV, Random, 95% CI) | ‐72.04 [‐137.84, ‐6.25] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 4.1 Energy (kcal) consumption Show forest plot | 6 | 732 | Std. Mean Difference (IV, Random, 95% CI) | 0.05 [‐0.17, 0.27] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 5.1 Energy (kcal) consumption Show forest plot | 2 | 400 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.06 [‐0.26, 0.15] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 6.1 Energy (kcal) consumed during a meal Show forest plot | 2 | 267 | Mean Difference (IV, Random, 95% CI) | 15.48 [‐20.08, 51.04] |
| 6.1.1 Restrained eaters | 2 | 129 | Mean Difference (IV, Random, 95% CI) | 20.87 [‐37.44, 79.18] |
| 6.1.2 Unrestrained eaters | 2 | 138 | Mean Difference (IV, Random, 95% CI) | 10.98 [‐38.85, 60.81] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 7.1 Energy (kcal) consumed during a snack Show forest plot | 1 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.17 [‐0.63, 0.28] | |
| 7.1.1 Restrained eaters | 1 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.44 [‐0.94, 0.05] | |
| 7.1.2 Urestrained eaters | 1 | Std. Mean Difference (IV, Random, 95% CI) | 0.03 [‐0.34, 0.39] | |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 8.1 Energy (kcal) consumed during a snack/meal Show forest plot | 8 | 1705 | Mean Difference (IV, Random, 95% CI) | ‐50.28 [‐104.42, 3.87] |
| 8.1.1 Studies conducted in the USA | 5 | 895 | Mean Difference (IV, Random, 95% CI) | ‐70.57 [‐167.65, 26.52] |
| 8.1.2 Studies conducted in other countries | 3 | 810 | Mean Difference (IV, Random, 95% CI) | ‐58.18 [‐107.15, ‐9.21] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 9.1 Energy (kcal) consumed during a snack/meal Show forest plot | 6 | 732 | Std. Mean Difference (IV, Random, 95% CI) | 0.05 [‐0.17, 0.27] |
| 9.1.1 Studies conducted in the USA | 4 | 459 | Std. Mean Difference (IV, Random, 95% CI) | 0.14 [‐0.17, 0.45] |
| 9.1.2 Studies conducted in other countries | 2 | 273 | Std. Mean Difference (IV, Random, 95% CI) | ‐0.12 [‐0.36, 0.11] |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 10.1 Energy (kcal) consumed during a snack/meal in laboratory settings Show forest plot | 5 | 718 | Std. Mean Difference (IV, Random, 95% CI) | 0.19 [‐0.14, 0.51] |
