Overweight and obese adults are at increased risk for morbidity and mortality associated with many acute and chronic medical conditions, including hypertension, dyslipidemia, coronary heart disease, diabetes mellitus, gallbladder disease, respiratory disease, some types of cancer, gout, and arthritis. In addition, overweight during childhood and adolescence is associated with overweight during adulthood, and previous reports have documented an increase in the prevalence of overweight among children, adolescents, and adults from 1976-1980 to 1988-1991. This report presents data from CDC's Third National Health and Nutrition Examination Survey (NHANES III) (1988-1994) to provide the most recent national estimates of overweight among children (ages 6-11 years), adolescents (aged 12-17 years), and adults (aged > or = 20 years) in the United States. The findings indicate that the prevalence of overweight in the United States has continued to increase.