Prevalence and factors associated with overweight and obesity in French primary-school children.

OBJECTIVE To determine the prevalence of, and identify associated factors with, overweight and obesity in two samples of French children. DESIGN We conducted two cross-sectional studies among two samples of children. Weight status, eating behaviour, sedentary activity, physical activity and parents' socio-economic status (SES) were collected using questionnaires filled by doctors during school health check-ups. Overweight and obesity were defined according to the age- and sex-specific BMI cut-off points of the International Obesity Taskforce. Multivariate analysis (logistic regression) was used to identify independent factors associated with overweight including obesity and obesity alone. SETTING Aquitaine region (south-west France). SUBJECTS Analyses were conducted among children aged 5-7 years (n 4048) and 7-11 years (n 3619). RESULTS Overweight prevalence was 9·5 % including 2·2 % of obesity in 5-7-year-old children and 15·6 % including 2·9 % of obesity in 7-11-year-old children. In both samples, overweight and obesity prevalence were higher in children whose parents had low or medium SES (P < 0·05). Factors associated significantly (P < 0·05) and independently with higher overweight or obesity prevalence were female gender, low or medium parental SES, never or sometimes having breakfast, never eating at the school canteen, never having a morning snack, never or sometimes having a light afternoon meal and having high sedentary activity. CONCLUSIONS Our data confirm that low SES, absence of breakfast and high sedentary activity are associated with a higher risk of being overweight or obese, but also highlight original potential protective factors such as eating at the canteen and high meal frequency.