Jan. 28, 2010 -- People who carry a few extra pounds after age 70 tend to live longer than people who don’t, new research finds.
Overweight older adults who took part in the Australian study had a clear survival advantage over those who were normal weight, underweight, or obese.
The findings suggest that the widely accepted body mass index (BMI) weight guidelines may not be particularly useful after age 70, lead researcher Leon Flicker, PhD, of the University of Western Australia tells WebMD.
He says elderly people who don’t have health conditions like diabetes or osteoarthritis, which are caused or exacerbated by carrying extra pounds, may be better off being overweight.
“Unless they have these conditions, there is not much reason to tell people in their 70s and beyond to lose weight if they are not obese,” he says.
Elderly Benefit From Extra Weight
The study is not the first to suggest that carrying some, but not too much, extra weight may increase longevity.
Last summer, researchers in Canada reported the same findings after analyzing data from more than 11,000 adults followed for more than a decade.
In that study, people who met the criteria for being overweight were 17% less likely to die compared to people of normal weight.
In the newly reported research, overweight study participants in their 70s followed for up to 10 years had a 13% lower risk of death than participants classified as normal weight.
BMI is calculated by dividing a person’s weight (in kilograms) by the square of their height (in meters). A body mass index of 18.5-24.9 is considered normal, a BMI of 25 to 29.9 is considered overweight, and a BMI of 30 or more is considered obese.
Based on BMI scores, a 5-foot, 7-inch adult would be considered:
- Underweight at less than 118 pounds (BMI <18.5),
- Normal weight at 118 to 159 pounds (BMI = 18.5-24.9)
- Overweight at 160 to 191 pounds (BMI = 25-29.9)
- Obese at 192 pounds or more (BMI = 30+)
Obese and normal-weight study participants had a similar risk of death over the 10 years of follow-up. Underweight study participants had the highest risk of death, even after the researchers adjusted for the wasting effects of disease.
Exercise Lowered Death Risk
Women who were sedentary were twice as likely to die as women who got regular exercise, regardless of BMI.
The effect was seen in men, but to a lesser degree. A sedentary lifestyle was associated with a 28% increase in death among men.
The study appears in the February issue of the Journal of the American Geriatrics Society.
“There is a lot we can’t really explain in our findings, and the fact that a sedentary lifestyle seemed to be more risky for women than men is one of them,” Flicker says.
Flicker believes the BMI thresholds for overweight and obese are too restrictive for older people, and he says it may be time for the World Health Organization to change the guidelines to reflect the findings from his and other studies.
Geriatric medicine specialist Thomas Yoshikawa, MD, of UCLA’s David Geffen School of Medicine, agrees.
“From a hard science point of view it may be a bit premature, but my own personal belief is this is something we should carefully consider,” he tells WebMD.
Yoshikawa says as many as two dozen observational studies suggest that carrying a few extra pounds is beneficial for people in their 80s and older.
Although extra pounds clearly add to the risk for chronic diseases like heart disease and diabetes earlier in life, they may actually give older people extra reserves to recover from stresses like surgery or pneumonia, he says.
“I would rather have an elderly patient who is in relatively good health and is close to normal weight gain five or 10 pounds than lose five or 10 pounds,” he says.