This study aimed to assess consumers' perceptions about the impact of consumption of different foods on health and body weight, as well as to identify risk perceptions about food-related chronic diseases. Face-to-face questionnaires were conducted with 525 Brazilians. Individuals were asked about their perception of risks associated with the consumption of 50 food items on health and bodyweight. The unrealistic optimism was measured by asking participants about their risk and the risk of another person with similar body and health conditions of developing diabetes mellitus (DM), systemic arterial hypertension (SAH), and gaining 3 to 10 kg in the next 12 months. According to the principal component analysis, biased perception of food healthiness and weight gain was observed. Some UPF were perceived as healthy (e.g., gelatin, cereal bars, cream cracker), indicating a false healthy stereotype. Regarding the bodyweight effect, some typical Brazilian staple foods, such as rice, pasta, bread, and potatoes, were considered fattening foods. Optimistic bias was found for DM, SAH, and weight gain, and perceived control over health correlated negatively to risk perception of all hazards. Some motives for food choice and perceptions about foods affected the risk perception about chronic disease. Consumers with higher income, highly educated, and without children perceive higher health benefits in food than risks. These results indicate that health campaigns must be unbiased, clarifying the level of food processing and health effects, especially for the food stereotyped as healthy and fattening.