[Obesity in the child].
The prevalence of childhood obesity increases dramatically in all industrialized countries. As in adults, it is defined by an increase in fat mass. The United States seem to be facing the most difficult situation. However, rapid changes in the way of life leads to consider that, in a near future, as much as 25% of the children in Europe could be concerned as well. A new epidemiological tool designed by the International Obesity Task Force takes as reference criteria the body mass index and will allow comparisons between countries as well as it will take into account the physiological variations of fat mass during growth. GENETICS AND ENVIRONMENT: A NEW PUZZLE: Inactivity seems to account as much as increased or unbalanced food intakes. While genetics account for a part of the disease at the population level, its role remains unclear in individuals. Most complications occur early in life, in a silent and progressive way. All these aspects do not only open fields of research but also provide new understanding and therapeutic basis for clinicians. PREVENTION: A PUBLIC HEALTH PRIORITY: Prevention has become a priority which should be based on early individual surveillance and Health Policy programs based on "National Recommendations for the diagnosis, prevention and treatment of obesity". All professionals dealing in one way or another with children lifestyle are concerned as well as do the families.