Adolescents who live in poverty are more likely to be overweight

May 23 2006

Adolescents aged 15-17 years who live in poverty are more likely to be overweight than those not living in poverty, a difference that has emerged in the past decade, according to a study in the May 24/31 issue of JAMA: The Journal of the American Medical Association.

The number of adolescents in the U.S. who are overweight has more than doubled during the past 3 decades. As the prevalence of adolescent overweight continues to increase, so too will its associated consequences, including type 2 diabetes mellitus, hypertension, obstructive sleep apnea, poor quality of life, and increased illness and risk of death in adulthood, according to background information in the article. Whether the increasing prevalence of adolescent overweight is characterized by larger, smaller, or unchanged disparities in overweight status across socioeconomic strata has not been known.

Richard A. Miech, Ph.D., M.P.H., of Johns Hopkins University, Baltimore, and colleagues examined trends in the prevalence of overweight among adolescents aged 12 to 17 years by family poverty status. The researchers used data from four cross-sectional, nationally representative surveys (U.S. National Health and Nutrition Examination Surveys [NHANES] of 1971-1974, 1976-1980, 1988-1994, and 1999-2004).

The authors found that trends in the association of adolescent overweight with family poverty differed by age groups. There was a widening disparity among 15- to 17-year-old adolescents from poor families. This trend was similar among male, female, non-Hispanic white, and non-Hispanic black adolescents, resulting in an overall prevalence of overweight in 1999-2004 more than 50 percent higher among adolescents in poor vs. nonpoor families (23.3 percent vs. 14.4 percent, respectively). In contrast, for 12- to 14-year-old adolescents, prevalence did not significantly differ by family poverty status in any of the surveys; although among non-Hispanic black adolescents, overweight prevalence increased faster in nonpoor vs. poor families.

Additional analyses suggest that physical inactivity, sweetened beverage consumption, and skipping breakfast may contribute to these disparities. The researchers found that among respondents aged 15 to 17 years, the increase in the proportion of calories from sweetened beverages across the last 2 NHANES surveys (1988-1994 and 1999-2002) was significantly larger in poor families (from 9.2 percent to 15.4 percent) compared with nonpoor families (from 11.1 percent to 12.6 percent). Among older adolescents aged 15 to 17 years, the absolute difference in the disparity across poverty status in the prevalence of breakfast skipping increased from 1.1 percent to 16.2 percent across the last 2 NHANES surveys.

"The observed differences across older vs. younger adolescents are consistent with the greater autonomy that comes with increasing age. Adolescents aged 15 to 17 years vs. those aged 12 to 14 years have more opportunities to purchase their own food and determine their own leisure time pursuits and also have more discretionary income with which to act on their preferences," the authors write.

"These results suggest that efforts to reduce health disparities in the United States require monitoring of population health, so that emergent disparities and their underlying causes can be detected and addressed at early stages of their development."