Correlates of obesity in African-American girls: an overview.

Abstract

II (1976 to1980), the prevalence of overweight in children has doubledfrom 7% to 15% in children 6 to 11 years old and nearlytripled from 5% to 15% in adolescents 12 to 19 years old(1). Although childhood obesity is present across all demo-graphic and social classes, certain subgroups of the U.S.population are at increased risk. In particular, African-American preadolescent and adolescent girls show higherrates of overweight compared with their white counterparts.According to NHANES 1999 to 2000, African-Americangirls are twice as likely to be overweight as white girls at 6to 11 years old (22.2% vs. 11.6%, respectively) and 12 to 19years of age (26.6% vs. 12.4%, p 0.05) (1). Likewise,data from the National Heart, Lung, and Blood Institute(NHLBI) National Growth and Health Study (NGHS) (1987to 1997) on 9- to 10-year-old African-American and whitegirls show that African-American girls have significantlyhigher mean BMI than white girls at 9 years of age (18.5 vs.17.5, p 0.0001) and 10 years of age (19.8 vs. 18.4, p 0.0001) (2). Findings also indicate that by the age of 19,over one-half of the African-American girls in the NGHScohort were overweight, and more than one-third wereobese (3).Because childhood overweight has been increasingly rec-ognized as a public health problem, a considerable amountof research exploring the correlates of childhood overweighthas emerged. A large number of factors both proximal anddistal to the individual have been identified as contributingto the increasing prevalence of overweight among youth,including genetic, familial, socioeconomic, psychosocial,behavioral, and environmental factors (4). Although thiswork has begun to shed light on the complexity of theobesity epidemic and has been informative with respect totargeting prevention and treatment efforts, considerably lessinformation is available regarding determinants of over-weight among African-American girls in particular. TheNHLBI NGHS, a biracial observational cohort study, pro-vided a wealth of information about the development ofobesity among African-American and white girls (5,6).However, many questions remain unanswered.Phase 1 of the Girls Health Enrichment Multisite Studies(GEMS) program, which had the goal of developing andpilot testing culturally appropriate interventions to preventexcessive weight gain in 8- to 10-year-old African-Ameri-can girls, provides an additional important opportunity tobetter understand the correlates of obesity in this popula-tion. Phase 1 of GEMS was a 2.75-year development phaseduring which investigators from four field centers (Univer-sity of Memphis, University of Minnesota, Baylor Collegeof Medicine, and Stanford University) with the assistance ofa coordinating center (George Washington University) andparticipation by the NHLBI conducted formative evaluationto develop their individual obesity prevention approaches.The field centers then independently developed and pilottested their own interventions during a 12-week pilot study.Although the interventions were different at each field cen-ter, evaluation protocols with key commonalities were used,providing a rich data set to examine correlates of over-weight among a geographically diverse group of preadoles-cent African-American girls. Although not including anexhaustive list of all possible correlates of overweight, thepapers in this supplement are unique in their focus on a widerange of potential correlates of obesity, including psycho-social, diet, physical activity, biological, and maturationalfactors.Ethnic disparities in prevalence of overweight highlightthe importance of examining the cultural differences amongchildren from different racial/ethnic backgrounds and theirvaried effects on adiposity. For example, African-Americangirls and women experience less social pressure about theirweight, tend to be more satisfied with their bodies, and haveless negative attitudes about overweight compared withwhite girls and women (7–18). These cultural differences