Secular increases in relative weight and adiposity among children over two decades: the Bogalusa Heart Study

To examine trends in relative weight and obesity among 5- to 24-year-olds between 1973 and 1994.

A panel design consisting of seven cross-sectional surveys of schoolchildren and three surveys of post-high-school subjects. Anthropometric measurements included height, weight, and subscapular and triceps skinfolds.

All schoolchildren residing in Ward 4 of Washington Parish, Louisiana, a biracial community, were considered eligible; participation rates were >80%. Young adults were eligible if they had participated previously as schoolchildren. A total of 26,371 examinations were performed on 11,564 persons.

During the study period, substantial increases in mean levels of weight (0.2 kg/y) and skinfold thickness (0.15 mm/y) were observed; these changes were independent of height, age, and other covariates. The prevalence of overweight, defined by the 85th percentile of weight-for-height in 1973 to 1974, increased approximately twofold by 1994. Although secular increases were seen both among boys and girls and among blacks and whites, the largest increases were seen among 19- to 24-year-olds. Furthermore, the yearly increases in relative weight and obesity during the latter part of the study period (1983 through 1994) were approximately 50% greater than those between 1973 and 1982.

The increasing prevalence of obesity in early life indicates a need for primary prevention. Additional study is needed to determine whether these trends are continuing to accelerate and to examine possible explanations, such as diet and physical activity, for these changes.