Objective: To assess the influence of nutritional guidelines on the food habits of overweight and obese adolescents. Methods: A cross-sectional study with 22 overweight or obese adolescents was conducted. The nutrition intervention program, in which adolescents received only guidelines covering topics on healthy eating, lasted twelve weeks. First, anthropometric measurements of weight and height were performed to verify the nutritional status. Subsequently, a food frequency questionnaire was applied through interviews. Dietary and anthropometric measurements were performed, before and after the program, to verify the influence of nutritional guidelines on the food habits of adolescents. Results: Regarding protein consumption, legumes, meat, and milk and dairy products were the groups where the nutritional guidelines were more effective, except for the milk and dairy products group. The group of fats and fried foods also improved percentage after nutritional guidance. The other food groups were not favorably influenced by nutritional guidance. Conclusion: Although the implementation of nutrition education focusing only on issues related to food had no effect in changing inappropriate eating habits, this study allowed a critical reflection about the ineffectiveness of isolated strategies and the possibility of changes in eating habits through nutritional guidance, based on the sum of strategies described in the literature.