HOW WEIGHT ‘CREEPS’ UP
Many unwelcome changes stalk us as we age, but “weight creep” is among the most insidious. A 2011 study of 120,877 Americans found that people as young as their mid-30s begin to gain close to one pound per year, on average, with women slightly outpacing men.
To make matters worse, more of the weight we carry as we get older is fat and less of it is muscle. In men and women alike, cellular and hormonal changes that start at midlife promote a steady loss of muscle mass called sarcopenia. And in women nearing menopause, declining estrogen levels allow more fat to be stored in the belly and waist.
As muscle gives way to fat, the aging body burns fewer calories. And our thermostats get turned down, because stores of “brown fat” — a form of fat that intensively burns calories to create heat when we’re young — diminish with the passing years.
The problem is that even as our metabolisms downshift, few of us respond by paring our calorie intake or boosting our calorie expenditures through exercise.
Obesity appears to garble the hormonal signals that travel among the brain, gut and muscles and tell us to eat when we’re hungry and stop when we’re satisfied, says Dr. Louis J. Aronne, an endocrinologist and obesity expert at Weill Cornell Medical College in New York City. As these checks on appetite fail, weight gain can be hard to stop — or reverse.
This upward spiral is not universal, Aronne says: In Japan, people seem to change their consumption patterns around midlife, halting the process by which fat begets more fat.
What we eat matters. That 2011 study also found that as people aged, those who regularly ate potatoes in any form, consumed processed foods and routinely sipped sugary drinks or alcohol gained the most weight with age. So did those who watched the most television.
Sleep mattered too: Those who slept fewer than six hours a night, or more than eight, were more likely to gain steadily.
But the situation isn’t hopeless. The difference between holding steady and gaining nearly a pound a year is 50 to 100 calories a day. A brisk walk, or passing up a dietary indulgence, could make the difference.