Obesity Likely to Shorten Life by Nearly 10 Years for Americans
Being obese is likely to shorten life by nearly 10 years for America's young and middle-aged adults, according to research published in the medical journal, Obesity. The article, "Obesity and Early Mortality in the US," by James A. Greenberg, PhD, Associate Professor, Department of Health and Nutrition Sciences at Brooklyn College of the City University of New York, shows mortality is likely to occur 9.44 years earlier for study participants who were obese (BMI≥30). Further, Greenberg's study also made estimates for overweight (25 to <30kg/m2) individuals, and those with grade 1 obesity (BMI, 30 to <35) and grade 2-3 obesity (BMI, ≥35). Mortality was likely to occur earlier in these categories as well by 4.4, 6.7 and 14.2 years, respectively. The study's estimates apply to nonsmoking young and middle-aged adults without pre-existing serious illness who constitute about one third of American adults.
"While obesity is a serious health problem, there are few reliable measures of its health hazards in the U.S.," said Greenberg. "My objective was to estimate how much earlier mortality is likely to occur for Americans who are overweight or obese, with the end goal of improving awareness of the impact that excess weight has on longevity."
Using data from 37,632 participants in three National Health and Nutrition Examination Surveys (NHANES), Greenberg calculated the relative risk of death from all causes and number of years of life lost. All estimates were adjusted for demographic and lifestyle factors. The study also explored the effects of pre-existing illness, smoking, and older age on the number of years lost. The sample population is nationally representative of the United States.
Greenberg's findings confirm a large body of research that shows excess weight and obesity leads to higher morbidity and earlier death. Another recent large study, "Body-mass index and mortality among 1.46 million white adults," by Amy Berrington de Gonzalez et al. in the New England Journal of Medicine, confirms these findings.
"Experts agree the relationship between obesity and mortality is a complicated one," said Harvey Grill, PhD, President of The Obesity Society (TOS). "However, it's clear from a vast body of research that obesity and mortality are associated, and that a higher BMI is tied to earlier death as well as higher rates of disease, many of which are serious."
Less clear is the effect of individual factors and the length of follow-up of participants in studies on obesity and mortality. TOS encourages continued work by researchers to identify ways to improve the investigation into the relationship between obesity and mortality.