ABSTRACT Ultra-processed foods are industrial products that contain an unbalanced nutritional composition, contributing to a high intake of calories, sugars, fats and sodium. The aim of this study was to evaluate the consumption of ultra-processed foods among adolescents, adults and the elderly. In the city of Teresina, Piauí, adolescents (10 to 19 years old), adults (20 to 59 years old) and elderly persons (≥60 years old) were interviewed. The 24-hour food recall was used to assess food consumption with subsequent replication in 40% of the sample. Analysis of variance (ANOVA) with Bonferroni’s post-hoc test was used to verify the data, and the value of p<0.05 was adopted as significant. It was observed that adolescents who consumed a greater amount of ultra-processed foods (2nd and 3rd tertile) consumed significantly less grains and legumes. Among adults, it was observed that the tertiles with higher consumption of ultra-processed foods had significantly lower consumption of grains, meat, fruits, vegetables, legumes and eggs. Among the elderly, in the tertiles with higher consumption of ultra-processed foods, there was significantly lower consumption of grains and meat. We conclude that higher consumption of ultra-processed foods contributed to a lower consumption of unprocessed or minimally processed foods.