Objective: (1) To assess the prevalence of childhood overweight (OW) and obesity in France; (2) to examine how physical activity and sedentary behaviour are involved in the association between socioeconomic status (SES) and OW, while taking into account total energy intake.
Design and subjects: Representative sample of French children aged 3-14 years (n=1016) taken from the 1998-1999 cross-sectional French INCA (Enquête Individuelle et Nationale sur les Consommations Alimentaires) food consumption survey.
Measurements: Weight and height, leisure-time physical activity (LTPA), sedentary behaviour (TV viewing and video-game use), and SES were reported by parents or children by answering questionnaires; total energy intake was assessed using a 7-day food record.
Results: In total, 15.2% (95% CI: 13.0-17.6) of the children are OW (including obese), according to the IOTF (International Obesity Task Force) definition. OW is inversely associated with SES in children over 6 years of age. LTPA is negatively correlated to OW among the 3 to 5-year-old children only, whereas sedentary behaviour is positively related to OW in childhood and adolescence. From 6 years old on, SES is inversely associated with sedentary behaviour, which consequently may partly mediate the relationship between SES and OW.
Conclusion: This study confirms the association between SES, sedentary behaviour and childhood OW in France. It was performed before the launching of the French Program of Nutrition and Health (PNNS) in 2001 and will be repeated in 2006. This will contribute to monitoring both childhood OW and its main determinants at the population scale.