This cross-sectional and representative report for the Brazilian population showed that having a HFCP, characterized by the consumption of vegetables, legumes, cereals, and meat, is associated with a lower chance of CMD in adolescents. Moreover, eating practices of breakfast consumption and the practice of having the main meals with the family regularly are associated with a lower chance of CMD. However, having an UFCP characterized by the consumption of sweetened beverages, candies, chips, and stuffed cookies and lower consumption of fresh fruit is associated with increased chances of CMD.
Reports with non-Brazilian adolescents have found similar results when evaluating the association between consumption of unhealthy diets and the diagnosis of depression and anxiety [29, 30]. Other authors report associations between specific food groups such as sweetened beverages, especially soft drinks, chips, snacks, and fast food or takeaway meals with depression and anxiety [31, 32]. There is still no explanation of the mechanisms by which unhealthy foods worsen the mental health of adolescents, however, we know that food and the act of eating are part of a complex interaction of factors that involves the environment in which the individual is inserted and its particularities [33], potentiated by the psychic and physiological characteristics, particular to adolescence.
However, the adoption of healthy eating is associated with better mental health in adolescents. Renzaho, Kumanyika & Tucker (2011) [34], in a cross-sectional report with Australian children and adolescents aged between 4 and 12 years old, showed that the consumption of fruits and vegetables was associated with protection against emotional problems. Jacka et al. (2011) [29], in a longitudinal report with a two-year follow-up, observed that a healthy diet is a predictor of better mental health in adolescents.
In this context, in addition to acting in the prevention of Chronic Non-Communicable Diseases (NCDs), the adoption of a healthy diet can contribute to reducing the chances of CMD. Therefore, encouraging practices that promote healthy and adequate eating can be useful in preventing these disorders in adolescents. In Brazil, the National School Food Program (PNAE) seeks to encourage and guarantee the right to adequate and healthy food for children and adolescents enrolled in public schools [35]. In addition, the Food Guide for the Brazilian Population, of the Ministry of Health, encourages fresh and minimally processed food choices, based on a healthy daily diet, and advises against the consumption of ultra-processed foods in all age groups.
In the present report, we found that healthy eating practices, such as eating breakfast and having meals with the family were inversely associated with the presence of CMD in adolescents. Fulkerson et al. (2004) [31] also found that the consumption of breakfast, lunch, and dinner is associated with lower chances of depression in American adolescents. Also, skipping breakfast significantly increased the risks of stress and depressive mood in Korean adolescents [36]. Breakfast consumption is also associated with positive health outcomes, such as prevention of overweight and other NCDs [37], improved cognition, and adequate school performance in children and adolescents [38, 39]. Thus, the planning and consumption of healthy foods in this meal is also a protection strategy against CMD [8].
The presence of the family during meals is crucial for the construction of healthy eating practices, so much that the higher frequency of family meals is associated with fewer depressive symptoms and fewer emotional difficulties in adolescents [40]. Agathão et al. (2021) [9], in a longitudinal report, found that Regular meals with the family were a protective factor for the mental health of Brazilian adolescents aged between 12 and 17 years. Furthermore, the chance of having depression can be up to 4.5 times greater in adolescents who do not have the practice of having meals with the family (frequency less than or equal to once a week) [41].
It is understood that family meals are opportunities in which family members can connect and strengthen their bonds [9, 42]. Therefore, having meals with the family can be considered a protective factor for the presence of CMD in adolescents. In addition, the presence of parents at meals is positively associated with higher consumption of fruits, vegetables, and dairy products by adolescents [43]. Consequently, strategies that encourage families to eat together should be promoted.
This report has limitations, such as the cross-sectional design, which no causality between nutritional factors and mental health can be established, and the variables used in the composition of food consumption patterns, which were constructed from a single 24-hour food recall, which may not accurately characterize the practiceual consumption of adolescents. However, the strengths of this report should be considered, such as its originality, as we did not find, within our searches, articles that discuss the association of eating patterns, eating practices, and CMD.