Is carrying a few extra pounds into your senior years healthy? Advice has been mixed. Now, two studies published this month attempt to better define the ideal weight for fitness and longevity for adults over age 60.
The gist is that you don't need to worry about being slightly overweight, as long as that extra weight is maintained at a consistent level. However, being very overweight is detrimental to health, and exercising to lose body fat and to gain muscle mass is always beneficial.
Determining the ideal weight for older people has been somewhat of a Goldilocks pursuit, with researchers looking for what weight is not too thin, but not too fat. Studies have suggested that being slightly overweight can be protective. In theory, having a few extra pounds could be good if you, say, develop cancer and need to undergo chemotherapy, which can lead to rapid weight loss.
For example, a 2001 study by researchers at Yale University found that moderately overweight senior adults with a body mass index (BMI) of 27 — two points higher than the BMI of 25 that defines being overweight — lived longer than seniors who were either thinner or heavier. [11 Surprising Things That Can Make Us Gain Weight]
There's a fine line here, though, because carrying extra pounds is a risk factor for many types of cancer and other diseases. And, according to the researchers behind the two new studies, the general public has misinterpreted the Yale findings to mean that being very overweight is healthy.
One new study, published this month in the American Journal of Epidemiology by researchers at The Ohio State University in Columbus, found that seniors who maintained a stable, slightly overweight status were most likely to survive over the 16 years surveyed. Those seniors who had a so-called healthy weight going into the study (a BMI between 18.5 and 25) and who gained weight, but stayed below BMI 25, were slightly less likely to survive over the study period.
People in the obese group, with a BMI higher than 35 and who continued to gain weight, faired the worst among all the groups in the study. But next-to-last were normal-weight people who lost weight, but this was likely because they became sick, the researchers said.
The second study, appearing this month in the journal Obesity, was conducted by researchers at Wake Forest Baptist Medical Center in Winston-Salem, N.C., and supports intentional weight loss among senior adults. Whether weight loss is beneficial has been debated because of this notion that being overweight is protective.
In short, the researchers found that physical activity and weight loss for overweight and obese adults resulted in lower cardiovascular disease risk and improved mobility. This finding supports previous studies demonstrating that exercise builds muscle and bone strength, improves balance and coordination, prevents falls and enables seniors to enjoy a more vibrant lifestyle, they said.
"These results should help temper some of the safety concerns regarding the recommendation of intentional weight loss for older adults," said Kristen Beavers, the study's lead author and an instructor of geriatrics and gerontology at Wake Forest Baptist.
Both groups of researchers emphasized that exercise for most people positively affects health, and that no one who is at a healthy weight or slightly overweight should intentionally gain extra weight in the hopes of warding off disease or extending their longevity.
Hui Zheng of Ohio State, the lead author of first study, said that the negative effects of obesity on health are greatest for young people.
"Young people especially shouldn't think that being overweight is harmless," Zheng said. "Continuing to put on weight can lower your life expectancy."
Christopher Wanjek is the author of a new novel, "Hey, Einstein!", a comical nature-versus-nurture tale about raising clones of Albert Einstein in less-than-ideal settings. His column, Bad Medicine, appears regularly on LiveScience.