The obesity epidemic in this country is no secret. Flip on the TV news or open a newspaper and you’re likely to see a story about America’s continuing battle of the bulge.

But just how the condition affects the ability of older adults to function has not been known—until now.

A new study by two researchers at the University of Pennsylvania School of Medicine has found that older adults today are much more likely to suffer from disabilities than those a decade ago.

The odds of suffering from functional impairment have increased 43 percent among obese older adults, according to the study. It classifies obesity as someone with a Body Mass Index (weight in kilograms divided by height in meters squared) over 30, and older adults and anyone over 60.

“We defined two types of disability,” says lead author Dawn Alley, Robert Wood Johnson Health and Society Scholar at the Penn School of Medicine. “Function impairment based on people reporting that they had difficulty in tasks like walking a quarter mile or up 10 stairs, or lifting 10 pounds. That relates to your ability to get around in the world. Secondly, limitations in activities of daily living, older people’s ability to care for themselves and live independently. Ability to get in and out of bed, eating, and dressing.”

The researchers used data collected from 1988-1994 and 1999-2004 in the National Health and Nutrition Examination Surveys, conducted by U.S. Centers for Disease Control’s National Center for Health Statistics.
“It is representative of the U.S. population nationwide,” Alley says. “What’s nice about this survey is they actually measure people’s weight and height, because we know that when people self-report their weight they tend to under report.”

Obesity among older adults increased by 8.2 percent during the two periods of time examined, and the disability gap between obese and non-obese groups widened.

“We believe that two factors are likely contributing to the rise in disability among older, obese people,” says senior study author Virginia Chang, assistant professor of medicine at Penn and attending physician at Philadelphia Veterans Affairs Medical Center. “First, people are potentially living longer with their obesity due to improved medical care, and second, people are becoming obese at younger ages than in the past. In both instances, people are living with obesity for longer periods of time, which increases the potential for disability.”

Other studies have suggested that obese populations have become healthier since the 1960s. While obesity-related risk factors like high blood pressure and elevated cholesterol have decreased, this new research suggests that quality of life for obese older people may be deteriorating.

“I think the study is important because of this finding that the disability gap between normal weight and obese people is growing over time,” Alley says. “Whichever measure of disability you use, the gap between the normal weight and obese older person grew. That’s important because increasing obesity rates may slow improvements in the health of the elderly. We’ve been seeing declines [in the rates of disability among the elderly], and these results may slow those declines. The health improvements that older people are experiencing may not be experienced by obese people.”

While the researchers did not study interventions of any kind, they do have some advice for older adults who might be teetering on the edge of obesity.

“For an individual, I would say the thing people should do is talk to their doctor and think about what kind of exercise would be appropriate for them,” Alley says. “One of the few things we know prevents functionality decline is exercise.”

The study, funded by the Robert Wood Johnson Foundation Health and Society Scholars Program and through a grant from the National Institute of Child Health and Human Development, appeared in the Nov. 7 issue of the Journal of the American Medical Association.