Resumen

Context
Globally, 1 in 3 children under 5 years is undernourished or overweight, and 1 in 2 suffers from hidden hunger due to nutrient deficiencies. As children spend a considerable time at school, school-based policies that aim to improve children’s dietary intake may help address this double burden of malnutrition.

Objective
This systematic review aimed to assess the effects of implementing policies or interventions that influence the school food environment on children’s health and nonhealth outcomes.

Data sources, extraction, and analysis
Eleven databases were searched up to April 2020 and the World Health Organization (WHO) released a call for data due in June 2020. Records were screened against the eligibility criteria, and data extraction and risk-of-bias assessment were conducted by 1 reviewer and checked by another. The synthesis was based on effect direction, and certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.

Conclusions
Seventy-four studies reporting 10 different comparisons were included. The body of evidence indicates that interventions addressing the school food environment may have modest beneficial effects on certain key outcomes. Nutrition standards for healthy foods and beverages at schools, interventions that change how food is presented and positioned, and fruit and vegetable provision may have a beneficial effect on the consumption of healthy foods and beverages. Regarding effects on the consumption of discretionary foods and beverages, nutrition standards may have beneficial effects. Nutrition standards for foods and beverages, changes to portion size served, and the implementation of multiple nudging strategies may have beneficial effects on energy intake. Regarding effects of purchasing or selecting healthier foods, changes to how food is presented and positioned may be beneficial. This review was commissioned and supported by the WHO (registration 2020/1001698-0). WHO reviewed and approved the protocol for the systematic review and reviewed the initial report of the completed systematic review.