OBJECTIVE: To examine the relationship between demographic and socioeconomic factors and food consumption in Mexican adolescents. METHODS: A representative sample (n = 7 218) of Mexican adolescents (12-19 years old) was analyzed. Independent variables included age, gender, and main activity of the adolescents; gender and age of the head of household; socioeconomic position; size of town (rural, semiurban, or urban); and area of residence. The consumption frequency of 13 food groups was assessed. Through multivariate logistic regression models, the effect of independent variables over consumption frequency was evaluated. RESULTS: Among Mexican adolescents only one-third consumed fruits and vegetables daily, a little less than one-half consumed dairy products daily, one-third drank soft drinks daily, and one-fifth consumed sweets and salty snacks. Males reported higher consumption of legumes. Age increase was associated with higher frequency of milk consumption. Adolescents who worked and those who neither studied nor worked consumed fruits, sweets, and salty snacks less frequently. Eating fruits, vegetables, cereals, dairy products, bread, starchy vegetables, red meat, white meat, and fast food decreased with regard to socioeconomic position; on the other hand, the lower socioeconomic strata had more frequent consumption of legumes and soft drinks. CONCLUSIONS: There are groups of adolescents who are less likely to consume healthy foods (such as fruits, vegetables, and dairy products). Socioeconomic and cultural processes that can explain the differences observed are discussed.