Reducing the use of sugar in public schools: a randomized cluster trial

OBJECTIVE: To test the efficacy of nutritional guidelines for school lunch cooks aiming to reduce added sugar in school meals and their own sugar intake. METHODS: A controlled randomized cluster trial was carried out in twenty public schools in the municipality of Niteroi in Rio de Janeiro, Southeastern Brazil, from March to December 2007. A nutrition educational program was implemented in the schools in question through messages, activities and printed educational materials encouraging reduced levels of added sugar in school meals and in the school lunch cooks' own intake. The reduced availability of added sugar in schools was evaluated using spreadsheets including data on the monthly use of food item supplies. The cooks' individual food intake was evaluated by a Food Frequency Questionnaire. Anthropometric measurements were taken according to standardized techniques and variation in weight was measured throughout the duration of the study. RESULTS: There was a more marked reduction in the intervention schools compared to the control schools (-6.0 kg versus 0.34 kg), but no statistically significant difference (p = 0.21), although the study power was low. Both groups of school lunch cooks showed a reduction in the consumption of sweets and sweetened beverages, but the difference in sugar intake was not statistically significant. Weight loss and a reduction in total energy consumption occurred in both groups, but the difference between them was not statistically significant, and there was no alteration in the percentages of adequacy of macronutrients in relation to energy consumption. CONCLUSIONS: The strategy of reducing the use and consumption of sugar by school lunch cooks from public schools could not be proved to be effective.