Unintentional weight loss in older adults often leads to frailty, a decline in physical function and even death.
So is it wise for older, overweight women to embark on a weight loss program, New research from Wake Forest University Baptist Medical Center suggests that these women are better off trying to lose weight, even if they regain some of it.
"Our results suggest that losing weight through calorie cutting won't lead to increased disability in older women," said Jamehl Demons, M.D., lead investigator on a project evaluating the effects of weight loss on physical performance.
And even when some of the weight was regained, the women still came out ahead.
"It looks like they are better off than if they had never tried to lose weight," said Mary F. Lyles, M.D., lead investigator on an analysis exploring how dieting affected body composition.
The results of both projects , which are part of the larger Diet, Exercise and Metabolism in Older Women (DEMO) study , are being presented today (May 4) at the annual meeting of the American Geriatrics Society in Seattle.
It is well-known that weight loss , whether it is intentional or unintentional , results in the loss of both muscle and fat. Because people naturally lose muscle as they age, scientists have wondered whether it's safe for older adults to compound this effect by dieting.
"Weight loss without exercise is not widely advocated for older adults because of the potential to lose muscle and reduce physical function," said Demons, an assistant professor of internal medicine -- gerontology.
Her study evaluated 23 obese, postmenopausal, sedentary women with a mean age of 58 who participated in the DEMO study. For five months, their meals and snacks were provided by the study and contained 400 fewer calories than they needed to maintain their weight.
Participants' body composition and physical function were measured before and after the five-month period. Tests of physical function measured knee strength, hand-grip strength, walking speed, aerobic fitness and ability to quickly rise from a chair without using their arms. The women lost an average of 25 pounds, with muscle representing about 35 percent of the total loss.
"Despite the large amount of muscle loss, their aerobic fitness and their ability to rise from a chair showed a trend toward improvement," said Demons. "Their strength and walking speed did not change. This suggests that their weight loss through dieting wouldn't be expected to lead to increased disability."