The Obesity Paradox continued...
The study appears online this week in the journal Obesity.
It was conducted by researchers with Statistics Canada, McGill University, and the Kaiser Permanente Center for Health Research and funded by grants from the National Institute on Aging, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Canadian Embassy.
Kaiser's David Feeny, PhD, who was a co-author of the study, tells WebMD that there are theories, but no hard evidence, to explain why carrying a few extra pounds may add a few years to your life.
Overweight People Get More Treatment
Being extremely underweight is considered a marker for poor health and frailty in older adults. Even though the researchers tried to control for this, poor health could explain why study participants who weighed the least had the biggest risk of dying.
But it is less clear why those who are overweight would have a lower risk of death than those whose weight is considered normal.
Because being overweight is a risk factor for a host of chronic diseases, including heart disease and diabetes, one theory is that their survival advantage is due to the fact that they receive more aggressive treatments to prevent these conditions.
"We tend to be quicker to prescribe statins (to lower cholesterol) and drugs to control blood pressure to patients who are overweight and we are more likely to screen them for diabetes," says weight management expert Keith Bachman, MD.
Bachman leads Kaiser's Weight Management Initiative, but he was not involved with the study.
Because the study only examined death risk, and not disease incidence or quality of life, the risk vs. benefit profile of carrying a few extra pounds is unclear, Bachman says.
"Good health is more than a BMI or a number on a scale," he says. "We know that people who choose a healthy lifestyle enjoy better health."
Feeny adds that lifestyle choices such as eating well, exercising regularly, managing stress, and treating risk factors for chronic disease may be more important for longevity than losing a few extra pounds.
"And this certainly doesn't mean that people who are normal weight should go out and binge on ice cream to gain a few pounds," he says. "The dairy industry might like that, but it would not be a good idea."