The prevalence of overweight and obesity is on the rise among children worldwide, leading the World Health Organization (WHO) to describe it as a full-blown epidemic. Until recently, little was known about the situation in France. The National Nutrition and Health Program (PNNS), established in France in 2000, includes nine priority objectives. One of these is to halt the rise in the prevalence of childhood obesity. A national assessment of the situation was therefore necessary. A European Working Group on Obesity (ECOG) recommended a protocol for assessing overweight and obesity as well as their associated factors. This study, conducted in metropolitan France, follows this protocol and was carried out among more than 1,500 schoolchildren in the first and second grades of elementary school, aged 7 to 9 years. The collection of anthropometric measurements was standardized using detailed instructions provided to the school physicians who performed the assessments. Additional data on the children’s lifestyle and certain characteristics of their parents were also collected. The prevalence of overweight status according to French standards (97th percentile) was estimated at 16.3%. According to the International Obesity Task Force (IOTF) standards, the prevalence of overweight status was 18.1%; among these children, 3.8% can be considered obese according to these same standards. There were no notable differences by sex or age. These data show that the situation in France is comparable to that of most European countries, although few have provided such recent data to date. Despite the lack of older data at the national level, they also indicate a probable increase in these rates over time in France. Factors associated with obesity highlight the important role of a sedentary lifestyle. The children in this study spent significant amounts of time on sedentary activities such as watching television. This factor is associated with overweight and obesity among boys. Among girls, participating in sports appears to be the factor distinguishing those with a normal body weight from those who are obese. A significant relationship was found between parental overweight status and children’s anthropometric status, in both girls and boys. For example, 16% of overweight girls had an obese father, compared to 3% of those who were not overweight. A significant relationship was also found between parents’ socioeconomic status and childhood obesity: children whose mothers were in the blue-collar/white-collar worker group were more frequently obese compared to those whose mothers were managers or in intermediate-level professions, whether employed or unemployed. The association between childhood overweight or obesity and the father’s socio-occupational category was also significant: the prevalence of overweight among children whose fathers were manual laborers or clerical workers was 20.2%, compared to 12.1% among children whose fathers were managers or held intermediate-level positions. The limitations of this study lie primarily in its cross-sectional nature, which does not allow for conclusions regarding cause-and-effect relationships. Although not representative, the data collected provide insights into the situation in France and offer a basis for understanding the factors associated with childhood overweight or obesity. These are indeed factors to be taken into account in the formulation of public health policies, particularly regarding the identification of children at risk of being overweight or obese and their care. (R.A.)