Tracking and Changes in Dietary Patterns of Adolescents: A Longitudinal Study in Southern Brazil

Methods: Longitudinal study carried out in Southern Brazil since 1993. Two food frequency questionnaires were applied at ages 15 and 18 years. The analysis includes 3,911 adolescents. Latent class analysis was used to identify the DPs at 15 and 18 years. Results: We identified four DPs at 15 and 18 years. Three were similar in both ages: “Varied” (30.2% at age 15 years vs. 21.6% at age 18years), “Traditional” (24.9% at age 15 years vs. 23.7% at age 18years) and “Dieting” (19.4% at age 15 years vs. 28.7% at age 18years), and the fourth DP identified labeled “Processed Meats” (25.5%) at 15 years and “Fish, Fast Food and Alcohol” (26.0%) at 18 years. The three DPs identified at both ages showed poor general agreement (Kappa=0.1). DP tracking was observed in about one third of the adolescents. Conclusions: Our findings suggest a high adherence to a “Varied” DP at age 15 years and substantial changes in food habits and choices over time, resulting in an increase in the adherence to a “Dieting” DP at age 18 years.