Bethesda, July 24, 2000 -- The prevalence of overweight among African American women (almost 50%) is significantly higher than in white women (about 33%). Approximately 1 in 4 American children and adolescents is overweight, and African American girls are the fastest growing obese population in the country. Obesity is defined as an increased percentage of body fat, therefore, accurate methods to measure body fat are needed to study factors that contribute to the development of obesity in different ethnic groups.
Skinfold-thickness is the least invasive and most convenient method used to measure body fat. Calipers are used to pinch and measure various areas of the body such as the abdomen, hips, triceps and thighs. Results are plugged into an equation that estimates the percentage of body fat.
Recent research published in the American Journal of Clinical Nutrition shows that most skinfold-thickness equations used to determine body fatness were developed using data from white adults, and do not provide accurate measurements for adolescent minority populations who tend to deposit fat in a different pattern.
Investigators at the United States Department of Agriculture/Agriculture Research Service Children's Nutrition Research Center in Houston evaluated eight different skinfold-thickness equations and found that none of them accurately measure the percentage fat mass of African American adolescent girls.
Says lead author William W. Wong, PhD, "African American children tend to have larger skeletal bone and muscle mass and store fat in different anatomic locations than Caucasians. Our results identified an equation that best measures body fat in female adolescents; however, further refinement is needed to improve its accuracy for African American populations."
This work will help scientists evaluate the causes of obesity in African-American girls and women. The high prevalence of obesity and obesity-related diseases in America is alarming and has prompted nutrition scientists to investigate potential causes, treatments, and prevention strategies. Excess fat is created by overeating and lack of exercise; however, many factors may predispose certain individuals to obesity. We need to focus not only on weight loss strategies but also on the ethnic, socioeconomic, geographic, and other reference data that will allow us to understand and treat this disease.
Source: Public Information Committee for the American Society for Nutritional Sciences and the American Society for Clinical Nutrition.
Journal
American Journal of Clinical Nutrition