Critical periods in childhood for the development of obesity.

Critical periods of development have been well recognized for many behavioral and developmental processes. However, as others have pointed out, such periods have not been widely reported for nutritional diseases. Many observations suggest that two and possibly three critical periods exist for the development of obesity and its complications. These include gestation and early infancy, the period of adiposity rebound that occurs between 5 and 7 y of age, and adolescence. Obesity that begins at these periods appears to increase the risk of persistent obesity and its complications. The mechanisms that account for the increased risk associated with obesity at these ages remain unclear. Nonetheless, the existence of critical periods should serve to focus preventive efforts on these developmental stages.