Résumé : OBJECTIVE: To assess nutritional status based on weight and height variables in children aged 7-9-y-old in a city from the South of Brazil (Florianópolis) and to compare the prevalence of thinness and overweight and environmental factors between Brazil and France.METHODS: Randomly stratified samples of 7-9 y-old children (Florianópolis, n= 2.232; France, n= 1.582). Both studies followed the protocol recommended by the European Childhood Obesity Group. Weight and height were recorded according to World Health Organization recommendation. Thinness and overweight were defined using the French references. Physical activity and sedentary behaviors were compared.RESULTS: Florianópolis children were taller and heavier than the French. The frequency of thinness was lower in Florianópolis as compared to France (1.1 vs 3.9%). Overweight frequency was 19.9% in Florianópolis as compared to 16.3% in France. French children had a higher level of physical activity. In particular, 66.5% of French children had a regular sport activity compared to 35.7% in Florianópolis. In France, daily television and screen viewing time was 2 hours per day as compared to 3.3 hours in Brazil.CONCLUSION: Behavioral parameters, particularly sedentary lifestyle, could account for the higher prevalence of overweight in Brazilian children. Strategies to decrease the prevalence of overweight in children should take into account the particularities of each country.