Background: Adolescence is characterized by physical and psychosocial changes. This implies modifying or implementing correct nutritional habits at an early age, which would have an impact on a healthy adult life. Objectives: The FFQ of dietary patterns has not been estimated in the population of adolescents. Therefore, conducting a pilot, cross-sectional, comparative, and correlational study, we sought to identify frequently consumed foods in an adolescent population. Methods: As part of the methodology, a Food Frequency Questionnaire (FFQ) was given to a non-probability convenience sample of 178 subjects aged 14 to 19 years to evaluate the most frequently consumed foods. Results: This study showed that the diet of Mexican adolescents was characterized with little variability in the foods consumed: 28.20% of the population had a good consumption of milk (1 to 5 serving/day), 16.50% of sugars, and 16% of cereals, while only less than 15% had a good consumption of source animal foods, fruits and vegetables, oils, and fat. Conclusions: Mexican adolescents have demonstrated that their diet is poorly varied. Adolescence is an important period in life that can define habitual dietary intake, and therefore, it is crucial to promote healthy eating at this age. Further research and appropriate public policies are needed.

Background: Adolescence is a critical stage for establishing lifelong dietary habits and preventing non-communicable diseases through adequate intake of bioactive compounds. Numerous studies have thoroughly examined the antioxidant profile of traditional diets such as the Mediterranean diet. In contrast, current research provides limited insights into the antioxidant properties of foods typically consumed by Mexican adolescents. Objective: So, this study aimed to quantify the total phenolic compound (TPC) content and antioxidant capacity (AC) of frequently consumed foods and to estimate dietary intake in Mexican adolescents. Methodology: The selected food groups were identified based on their frequency of consumption by 15% or more of the adolescent population, considering those that have demonstrated a sufficient quantity of antioxidants. It was analyzed TPC and ABTS•⁺ and DPPH• to determine the antiradical activity of the analyzed samples. Results: The estimated daily intake of TPC was 1484.01 mg GAE/person, while AC intake was 345.67 mg AAE/person (ABTS•⁺) and 5399.14 µmol TE/person (DPPH•). Cereals and fruits were the major contributors to total antioxidant intake, while the contribution of leafy vegetables and nuts was relatively low. The statistical analysis revealed a significant positive correlation between TPC and AC. The results of the study indicate the antioxidant potential of the adolescent diet. Conclusions: Despite certain limitations, the values obtained from the study are comparable to those of other studies that employed similar methodologies. Consequently, promoting the early consumption of fresh plant-based foods rich in antioxidants, such as polyphenols, which can enhance the dietary profile and contribute to adolescents’ long-term health, constitutes a significant area of research.