This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

1) To study the effectiveness, and where possible, cost‐effectiveness, of school feeding programs in improving physical and psycho‐social health outcomes for low‐income elementary school children.
2) To study the potential of school feeding programs for reducing socioeconomic inequalities in health among elementary school children.
3) To identify and explore any adverse and unforeseen effects of school feeding programs
4) To explore the process elements of school feeding programs in order to identify their successful features and aspects of their delivery that might lead to adverse effects.