Longitudinal trajectories and prevalence of meeting dietary guidelines during the transition from adolescence to young adulthood

BACKGROUND: Establishing healthy dietary habits during adolescence and young adulthood is critical for long-term health. OBJECTIVES: This study assessed the prevalence of meeting US Dietary Guidelines and trajectories in dietary intake for 4 MyPlate food groups during the transition from adolescence to young adulthood. METHODS: Three waves of surveys and food frequency questionnaires were collected as part of Project EAT (Eating and Activity in Teens and Young Adults), a 15-y longitudinal study. Adolescents (n = 1177, 57% female, mean ± SD age 15.0 ± 1.5 y) were recruited in 1998-1999 in Minneapolis-St Paul, Minnesota public schools and were resurveyed twice in young adulthood at mean ± SD ages 25.3 ± 1.5 and 31.1 ± 1.5 y. The prevalence of meeting guidelines for each MyPlate food group was calculated at each time point. Mean daily servings were compared over 5 y in young adulthood through the use of paired t tests. Adjusted least-squares means were calculated to compare dietary intake in young adulthood across quartiles of adolescent intake. RESULTS: Adolescents had the highest prevalence of meeting dietary guidelines for fruit (37% for females and 30% for males) and dairy (53% for females and 61% for males); young adults >30 y had the highest prevalence of meeting dietary guidelines for vegetables (19% for females and 8% for males) and whole grains (23% for females and 17% for males). From the mid-twenties to early thirties, vegetable intake increased, whereas dairy intake decreased. Dietary intake generally tracked over time with individuals in the lower quartiles of intake at adolescence generally continuing to have low intake in young adulthood. CONCLUSIONS: Although the prevalence of meeting dietary guidelines for whole grains and vegetables, and daily servings of vegetables increased with age, improving intake of whole fruit, whole grains, dairy, and vegetables remains key during the transition from adolescence to young adulthood.