JP, JG, AP and MG are investigators on the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial. To avoid any conflict of interest, OC will independently assess the SHINE study for inclusion, and if required, will perform any data extraction.

JP: Student investigator on the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial. This trial (registered at clinicaltrials.gov as NCT01824940) is investigating the independent and combined effects of improved WASH and/or improved diet on stunting and anaemia in infants, and will include neurocognitive outcomes. It is therefore relevant to the current review.

JC: Student investigator on the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial. This trial (registered at clinicaltrials.gov as NCT01824940) is investigating the independent and combined effects of improved WASH and/or improved diet on stunting and anaemia in infants, and will include neurocognitive outcomes. It is therefore relevant to the current review.

AJP: Received Nestle Nutrition Institute funding to travel to a meeting on low birth weight babies, South Africa, April 2014. Funding received from Bill and Melinda Gates Foundation; Swiss Development Corporation; Department for International Development, UK; and Wellcome Trust (093768/Z/10/Z), for the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial, on which he is a coinvestigator in Zimbabwe. This trial (registered at clinicaltrials.gov as NCT01824940) is investigating the independent and combined effects of improved WASH and/or improved diet on stunting and anaemia in infants, and will include neurocognitive outcomes. It is therefore relevant to the current review. AJP is funded by the Wellcome Trust (108065/Z/15/Z).

OC: none.

KL: none
EA: none

MJG: Receives some funding from the World Health Organisation, UNICEF, Sight Savers and Autism Speaks for attendance at meetings and consultancy work relating to the assessment of child development and disability in low and middle income settings. She also holds grants from the Sir Halley Stewart Trust, Grand Challenges Saving Brains Canada and the British Academy of Childhood Disability on unrelated work. MJG is a coinvestigator on the SHINE trial (clinicaltrials.gov identifier NCT01824940), which is investigating the independent and combined effects of improved WASH and/or improved diet on stunting and anaemia in infants, and will include neurocognitive outcomes.