Prevalence of overweight and weight gain in the United States.

Data from the Second National Health and Nutrition Examination Survey (NHANES II) indicated that in the period 1976-1980 approximately 34 million US adults (25.7%) were overweight, with more women (19 million) than men (15 million) affected. Selected demographic factors, eg, low educational attainment and low family income were associated with the prevalence of overweight and with the incidence of weight gain. Analyses of the NHANES I Epidemiologic Follow-up Survey indicated that in a 10-y period, women had a greater mean weight gain. The overall incidence of a major weight gain (ie, an increase of five or more body mass index units) was twice as great among females (5.3%) than males (2.3%). Data on overweight and weight gain in the United States by selected demographic characteristics are summarized.