The results, published in a research letter in JAMA Internal Medicine, show 40% of men and 30% of women older than 24 are overweight. Another 35% of men and 37% of women are obese.
Researchers Lin Yang and Graham Colditz at Washington University School of Medicine in St. Louis used data on height and weight for more than 15,000 adults to calculate the percentage of adults who qualify as underweight, normal weight or overweight.
That a significant number of U.S. adults are overweight and obese was not a surprise to Yang, who studies the relationship between physical activity and cancer and the role that socioeconomic status and the environment play in health. “We kind of know the obesity epidemic is getting really severe,” she said.
Still, she was stunned by the actual number of obese American adults.
Obesity's rise across the U.S. has been accompanied by climbing medical costs, $147 billion by one 2008 estimate. The percentage of adults who maintain a healthy weight has declined to roughly 30% among adults age 20 and older. It was 42% two decades earlier. The trend has been stubbornly resistant to reversal, though recent data shows obesity among those ages 2 and 5 declined in the decade that ended in 2012.
The new study used data from the National Health and Nutrition Examination Survey in the years 2007-08, 2009-10 and 2011-12. Research published in JAMA in 1999 using the same survey found 63% of men and 55% of women were overweight or obese.
The research also underscored the disparities in U.S. obesity rates that have been identified elsewhere.
Among men, those most likely to be overweight or obese were Mexican American men, though those most like to be severely obese were non-Hispanic black men, Yang and Colditz reported. Non-Hispanic black women were most likely to be overweight or obese and were also the most likely to be severely obese. All women age 55 or older were more likely to be to be overweight or obese.
New public policy is seeking to raise American's awareness of healthy eating. The Food and Drug Administration announced it would prohibit use of artificial transfats by 2018, calling partially hydrogenated oils unsafe. But some nutritionists argue that sodium and sugar, not fat, are the real culprits. Meanwhile, rules that require restaurants to post calorie counts for menu items are scheduled to take effect next year, though House Republicans reportedly included a one-year delay in a recent spending bill.
Efforts to combat obesity should be broad and reach across all aspects of medicine and society to support individuals' effort to maintain a healthy lifestyle, Yang said. Strategies should include public policy, the workplace, the healthcare system and communities.
The percentage of adults who were severely obese increased across the board from 1999. Among men ages 25 to 54 the percentage increased to 4.59 in the most recent study compared with the 2.4% researchers reported in 1999. Among men age 55 or older the percentage increased to 4.3% from 0.82%.
Women saw similar increases among the severely obese. The most recent data show 8.2% of women ages 25 to 54 and 7.6% of women age 55 and older were severely obese. That's compared with 4.5% and 3.4%, respectively, reported in 1999.
Melanie Evans writes about healthcare finance, hospital management and governance issues. She has been part of the Modern Healthcare staff since 2004. Earlier in her career she covered healthcare and not-for-profits as a reporter at the Duluth (Minn.) News Tribune. She received a bachelor's degree in international relations from Boston University and a bachelor's in journalism from the University of Minnesota.Follow on Twitter