It’s a classic lament: Pounds seem to creep on with every passing year. And, unfortunately, the phenomenon is supported by the facts. “Starting at around age 40, the average American woman gains about a pound a year,” says Lewis Kuller, M.D., an obesity researcher at the University of Pittsburgh. That means by age 60, you may be carting around an extra 20 pounds and courting such problems as heart disease and diabetes.
At first glance, the cause is simple arithmetic: Eat more than you expend and eventually your pants will be too tight. But other factors, from your hormone levels to the size of your dinner plate, can complicate the equation. Chances are the weight gain is caused by physiological and lifestyle changes that you’ve barely noticed.
Knowing more about the four most common changes and understanding how they affect your weight will help you stay slimmer over time―and save you from needing new pants.
2 of 6Beatriz da Costa
Change: You Start Losing Muscle
Some of the weight gain that occurs with age is natural. Starting in your late 30s, you begin to lose muscle tissue, the body’s chief calorie burner. It’s replaced by fat, a relative freeloader. “Muscle burns about three times as many calories as fat, even at rest,” says John M. Jakicic, Ph.D., an exercise physiologist at the University of Pittsburgh. And, with age, muscle tissue simply doesn’t work as efficiently, for reasons not well understood. As a result, you’re not able to exercise as hard as you could in your 20s and you have less muscle mass to burn off last night’s cheesecake.
The metabolic downtick from these changes in body composition is fairly small, about 1 to 2 percent a decade. Still, burning several hundred fewer calories a week adds up over time.
Solution: Pump Iron
Few things fight the loss of muscle mass better than strength training with hand weights, resistance bands, or even your own body weight. It not only increases muscle tissue but also strengthens bones, which helps you stay active longer and work out harder. Many studies have shown that postmenopausal women who do strength training have an easier time staying active in their daily lives―walking, carrying groceries, climbing stairs―and this activity helps prevent further weight gain.
3 of 6Kana Okada
Change: Your Hormones Fluctuate
Over the decades, women’s bodies produce less of certain hormones―particularly estrogen, which typically starts ebbing in the 40s. It’s at that time, during the run-up to menopause rather than during menopause itself (which occurs on average at age 51), that sinking estrogen levels cause the most weight gain. “Since estrogen has appetite-regulating properties, many women experience cravings or find themselves hungrier than usual as their hormone levels drop,” says Jennifer Lovejoy, Ph.D., dean of the School of Nutrition and Exercise Science at Bastyr University, in Kenmore, Washington. Estrogen also affects how the fat in your body is distributed. As levels of the hormone decline, body fat tends to migrate from the hips and the thighs to the waist. Abdominal fat not only is more likely to cause health problems, such as heart disease and diabetes, but is also harder to shed than fat in other places. “Even if you control your weight and work out,” says Lovejoy, “there’s really not much you can do about the fact that your waist is going to expand a little bit.”
Other hormones factor in, too. Starting in their 40s, women (and men) experience a dramatic drop in levels of human growth hormone. One role of this hormone is to break down fat, preventing its storage around the belly. So as the hormone becomes scarce, a potbelly may become more noticeable.
Belly fat also accumulates in response to stress. Cortisol, a fight-or-flight hormone that is secreted in tense situations, channels fat to the midsection and intensifies cravings for high-fat foods―a double whammy for those who reach for French fries when under pressure. This can happen quite often, given the amount of angst that many women live with, juggling work and home, young children and aging parents. “If you’re someone who is susceptible to stress and high cortisol levels, it’s probably going to leave you with more of an apple shape,” says Elissa Epel, Ph.D., a psychologist at the University of California, San Francisco.
Solution: Eat Well and Reduce Stress
Alas, there is not much that you can do to prevent hormonally induced shape shifting. There’s no evidence that hormone-replacement therapy helps. A sensible diet and a substantial exercise regimen can minimize the spread, as can reducing stress (and cortisol levels) by relaxing, getting enough sleep, exercising, and finding other ways to stay calm.
4 of 6Kana Okada
Change: You’re Eating More
Some of the milestones that come with being an adult can lead you to pack on the pounds. Studies have shown that marriage tends to lead to weight gain, possibly because women dish out the same portions for themselves as for their husbands, who eat more. Having children (and eating their leftover chicken nuggets) can also lead to weight gain. A study published in the Journal of the American Board of Family Medicine found that women in households with kids consume more fat and calories than those without children. The researchers noted that the difference in fat was the equivalent of a slice of pepperoni pizza every day.
But even if you adhere to exactly the same diet for 20 years, you may gain weight as you age. In your 20s, you burn about 2,000 calories a day. By your 50s, thanks to those shifts in hormones and body composition, you burn only about 1,600 calories.
Step on a Scale “People who weigh themselves every day are, on average, seven to eight pounds lighter than those who don’t,” says Robert Jeffery, Ph.D., an epidemiologist and an obesity expert at the University of Minnesota, in Minneapolis. Tracking your weight allows you to cut back on meals or step up activity if you notice the needle rising. “Pay attention when it gets to about three pounds above what it was before,” says Deborah Tate, Ph.D., a clinical psychologist at the School of Public Health at the University of North Carolina, in Chapel Hill. A recent study that followed 314 successful dieters over 18 months found that when participants weighed themselves each day, most could avoid regaining more than five pounds.
See the Big in Small Changes Simple strategies to trim a few calories here and there can have a large effect. Tate suggests eating a portion-controlled frozen meal for either lunch or dinner as a way to keep overall calories down. Or “try starting meals with a bowl of vegetable soup or a plate of leafy greens,” says Barbara Rolls, Ph.D., a professor of nutrition at Pennsylvania State University, in University Park, and the author of The Volumetrics Eating Plan ($16, amazon.com). Both those foods fill the stomach and help satisfy the desire for more food.
Eat Mindfully “Over the course of a single day, a person makes more than 200 food decisions, most of them unconsciously,” says Brian Wansink, Ph.D., the author of Mindless Eating ($15, amazon.com). In studies, he has found that people are influenced by such factors as the size of their plates (the bigger the dish, the more that gets eaten) and whether they’re eating straight from the box or from a premeasured amount set on a dish. Use these findings to help you eat less. Buy smaller plates and skinny glasses. Repackage that barrel of pretzels from Costco into snack bags that conform to the recommended serving size. Little adjustments like this may pare only 100 to 200 calories from your daily diet, but in a year they can translate to 10 to 20 pounds that you’ve lost or haven’t gained.
5 of 6Monica Buck
Change: You’re Moving Less
In general, women’s activity levels peak in their early teens. In a recent report, 60 percent of high school girls said that they engaged in regular physical activity, while only 34 percent of women between 18 and 44 said the same. The percentages continued to decline among older age groups. Only about a third of middle-aged women get the 30 minutes a day of moderately intense exercise recommended by the U.S. Surgeon General. And there’s a direct line between activity level and weight: A recent study followed more than 9,000 men and women for 10 years and found that the least active people were seven times as likely as the most active to gain weight.
Deliberate exercise isn’t the only kind of activity that declines over the years. “People become more sedentary in ways they’re not even aware of,” says James Levine, Ph.D., an endocrinologist who researches activity levels at the Mayo Clinic in Rochester, Minnesota. “They buy a car and no longer need to walk to the bus. Their kids get older, so they’re not pushing a stroller anymore. Their knees ache, so they minimize trips up and down the stairs. They might even fidget less.” This drop-off can add up to a couple of hundred calories or more not burned each day. In one study, Levine found that obese people tend to sit for 150 more minutes a day than their naturally lean counterparts.
Pregnancy can also be a factor, especially if a woman puts on more pounds than recommended with each child. One recent study found that women who gained excess weight while pregnant were nearly three times as likely to be overweight six months after the baby was born. Marriage and a growing family can also cut down on a woman’s ability to exercise. Women with a husband and children report finding less time to get to the gym or take that daily walk.
Become More Active To keep your weight down, you’ll probably need to put in more than the government’s recommended 30 minutes of brisk walking, five times a week. “We’ve seen that there is a much better effect if it’s 50 to 60 minutes, five days a week,“ says Jakicic. Sounds daunting, but you can get the same benefit (and still hold down a job) by breaking that up into 10-minute bouts scattered throughout the day. Take a quick walk during a coffee break, or bypass the elevator and spring up the stairs. Do jumping jacks while waiting for your coffee to brew. When you’re in a meeting, walk as you talk. Pace when you’re on the phone.
Push Yourself at the Gym Make sure that you’re not on autopilot when you’re doing a workout. Researchers at Yale University who followed a group of 5,000 middle-aged men and women over 7½ years found that the ones who kept raising their fitness levels were most likely to lose weight or manage their weight.
Do Downward Dog A 2005 study in the journal Alternative Therapies compared middle-aged men and women who regularly practiced yoga with those who rarely did and found that the yogis were less likely to gain weight in the four years covered by the study. Those who started out overweight lost five pounds, while the non-yogis gained 13½ pounds. “Body awareness is a big thing in yoga,” says Alan Kristal, Dr.P.H., the author of the study and an epidemiologist at the Fred Hutchinson Cancer Research Center, in Seattle. “Imagine how that also translates into eating. When you’re aware that you’re no longer hungry, you stop eating.”
6 of 6John Lawton
Where the Time Goes
How active are you? If you’re like most Americans, the answer is: not very. Below are the activities undertaken by the average woman over age 18, listed from most to least time spent on them, according to a national survey sponsored by the Environmental Protection Agency. When Gladys Block, Ph.D., a public-health professor at the University of California, Berkeley, analyzed the responses, she was shocked by how little time the average person spent moving around. “We’ve known that people aren’t very active,” she says. ”This study reveals that it’s worse than we thought.”
Taking care of children (feeding, bathing, entertaining).
Watching television or seeing movies.
Working, office work (typing, computer work).
Cleaning house, general housekeeping.
Doing seated activities (e-mail, bill paying, Web surfing).
Talking to others, in person or by phone.
Working, light activity (walking to coworkers' offices or to the printer or copier).