RESUMEN
OBJECTIVE: We determined the prevalence by age and sex and associated factors of overweight and obesity in French adolescents. METHODS: We conducted a cross-sectional study of 2385 adolescents aged 11-18 y (1213 boys and 1172 girls) from middle and high schools in the Aquitaine region (southwest France) in 2004-2005. Weight and height were measured, and adolescents filled in a questionnaire about their characteristics and those of their parents. Overweight and obesity were defined according to the age- and sex-specific body mass index cutoff points of the International Obesity Task force. RESULTS: Prevalence of overweight (obesity included) was greater in boys and younger children. The odds ratio (OR) for an adolescent being overweight increased with parents' being overweight (at least one parent overweight, OR 1.97, 1.48-2.62, P<0.0001), low paternal socioeconomic status (OR 1.78, 1.22-2.60, P<0.01) and sedentary behavior (22 h/wk, OR 1.33, 1.02-1.74, P<0.05), and decreased with physical activity of parents (at least one parent active, OR 0.67, 0.51-0.89, P=0.01). CONCLUSION: Our data support the hypothesis that parental overweight and low socioeconomic status and adolescents' sedentary behavior are strong risk factors for adolescent overweight and obesity, and that parents active lifestyle is associated with a lower risk of overweight in their adolescents.