Body composition assessment in American Indian children

The prevalence of obesity in children throughout the U.S. population has increased in the past 30 years. This increase in obesity is also apparent in many American Indian tribes throughout this country, however, accurate estimates of the extent of obesity is limited by the use of body mass index as the only index of obesity. The present study was designed to develop a valid field method of estimating percent body fat (PBF) in American Indian elementary school children to evaluate the effectiveness of a comprehensive school-based intervention program for the primary prevention of obesity. An equation to estimate PBF was developed in a sample of 98 American Indian children using body water as estimated by deuterium oxide as the criterion method. The best predictors of PBF were the combination of height, weight, skinfolds and bioelectric impedance variables. Existing equations derived on non-Indian children underestimated body fat 5 to 8% in this measurement. A pilot study was completed on 156 fifth grade Indian children. The mean PBF of this sample was 35.6% ±6.9 for boys (N=81) and 38.8% ±8.5 for girls (N=75), which exceed the 85th percentile from various national samples (NHES, NHANES, NCYFS). Supported by NHLBI.