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 Dr. Lewis Kuller, 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.
1. 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, 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.
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2. 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, 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, 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.
3. 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.
Solutions: 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, 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, 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, a professor of nutrition at Pennsylvania State University, in University Park, and the author of The Volumetrics Eating Plan. Both those foods fill the stomach and help satisfy the desire for more food.
“Over the course of a single day, a person makes more than 200 food decisions, most of them unconsciously,” says Brian Wansink, the author of Mindless Eating. 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.