To this end, research was conducted together with Nutrebem, a private nutrition company, in school canteens in Belo Horizonte. After this, a short-term local promotional program (a prize drawing) was introduced, linked to the purchase of healthy products, involving 208 children and adolescents at three schools. In addition, 140 students at a fourth school served as a control group. Statistical analysis compared the average number of healthy products acquired by participants before, during and after the intervention (26 working days before it began, nine working days after it began, and 28 working days after it ended). The results indicated a clear short-term effect. The program significantly increased purchases of healthy products promoted during the intervention period at the schools, especially among girls and younger children. On average, no long-term effect was observed, however. Purchases of healthy products returned to pre-intervention levels immediately after the end of the promotional program. Among students who bought the items promoted during the intervention period, there was an increase in total consumption of products, including those of less nutritional value. As a result, the authors observed that short-term promotional programs may not lead to long-term behavioral changes. The study shows policymakers that they ought to encourage long-term changes in dietary behavior in school canteens. They should avoid the isolated use of promotional programs. When used, these initiatives ought to be associated with other strategies.