Objective To examine whether having family meals as an adolescent protects against becoming overweight or obese 10 years later as a young adult. Study design Data from Project Eating and Activity in Teens -III, a longitudinal cohort study with emerging young adults, were used. At baseline (1998-1999), adolescents completed surveys in middle or high schools, and at 10-year follow-up (2008-2009) surveys were completed online or via mailed surveys. Young adult participants (n = 2117) were racially/ethnically and socioeconomically diverse (52% minority; 38% low income) between the ages of 19 and 31 years (mean age = 25.3; 55% female). Logistic regression was used to associate weight status at follow-up with family meal frequency 10 years earlier during adolescence, controlling and testing for interactions with demographic characteristics. Results All levels of baseline family meal frequency (ie, 1-2, 3-4, ≥5 family meals/wk) during adolescence were significantly associated with reduced odds of overweight or obesity 10 years later in young adulthood compared with never having family meals as an adolescent. Interactions by race indicated that family meals had a stronger protective effect for obesity in black vs white young adults. Conclusions Family meals during adolescence were protective against the development of overweight and obesity in young adulthood. Professionals who work with adolescents and parents may want to strategize with them how to successfully carry out at least 1 to 2 family meals per week in order to protect adolescents from overweight or obesity in young adulthood.