Abdominal body fat has been identified as an independent risk factor for disease in young people, in particular for metabolic alterations leading to insulin resistance and for cardiovascular risk. The prevalence of abdominal obesity is increasing in adolescents in both developed and developing countries, and both diet and physical activity seem to be the key lifestyle targets for its prevention these age groups. In this chapter, we present scientific literature on the role of food patterns and physical activity in abdominal body fat in adolescence. Interventions combining both lifestyle factors seem to have additional benefits than isolated interventions based exclusively on diet or physical activity. It is important to note, however, that effecting positive changes in food patterns and physical activity during adolescence continues to be a challenge.