Background: Chilean school children present a high prevalence of cardiovascular risk (CVR) factors related with bad eating practices and sedentary habits, including overweight and obesity. Objective: to evaluate the impact on RCV of improving the quality of meals delivered by State programs for school children and optimizing their physical activity. Methods: an intervention study was realized in 269 children of both sexes attending third basic grade during 2013 in Quillota, Chile. The subjects were randomized into four groups: Control (C, no intervention); Intervention in diet with the addition of dehydrated vegetables into desserts and jellies given at lunch (D); Intervention in physical activity, improving quantity and quality (PA); Intervention in diet and PA (DPA). Anthropometry and biochemical serum markers were assayed before and after the intervention. Results: no evidence of change in nutritional status as an effect of the interventions was observed during the annual school period. The level of triglycerides and VLDL-cholesterol augmented in the group C but not in the intervened groups. Plasma levels of total cholesterol, LDL-cholesterol and glucose did not differ in children from groups D, PA and DPA versus Control. Conclusion: even though the intervention of diet and/or physical activity in children during a school year was probably too short to support changes in the nutritional status, a reduction in some CVR factors may already be observed.