For women with some extra time on their hands, a new study offers another way to prevent the weight gain that comes with age: Simply exercise.
For nearly 22,000 minutes a year.
That’s 60 minutes every day, 365 days a year, no holidays, no sick days. Granted, this is “moderate exercise,” which is defined as something akin to a leisurely bike ride or a brisk hour-long walk. Women who can’t squeeze that into their schedule can increase the intensity of their workout and halve the time: a 30-minute spin class, a half-hour spent swimming laps. But again, that’s every day, rain or shine.
Overweight women in the study actually gained slightly more weight than women who were couch potatoes.
“I don’t want people to throw up their hands and say, ‘I can’t do it,’” the study’s lead researcher told The Wall Street Journal. Except that maybe we do need to do some serious rethinking about what we ask of people and why. Because while exercise is essential for health, when it comes to weight control this new study suggests that the average woman can expect to avoid 0.1 ounces of weight gain a month. In other words, out of the average typical yearly weight gain of 8 ounces per year, she is likely to prevent a less-than-whopping 1.3 ounces—barely more than one-sixteenth of one pound—that would have otherwise occurred without all those trips to the gym.
With numbers like these, can we finally get rid of the propaganda that exercise is a panacea for weight problems? Far from encouraging women to hit the gym even harder, a study like this should send the message that although exercise has many wonderful benefits, preventing weight gain isn’t one of them.
It should be noted that this new data is not from some fringe, low-quality study that might be disproved by future research. It’s published in the prestigious Journal of the American Medical Association, and its sample was a huge population of 34,070 women studied over 13 years. A nutrition research study this large is a rarity because of the costs and time involved, but there is usually no better way to get definitive answers to big questions. That is why we should listen even when the message is less encouraging than some smaller studies published in the past.
A closer look at the study also reveals that for overweight women, the results are even less encouraging. Women in the study who had a body-mass index of 25 to 29.9 (this is the technical classification for overweight— click here) reaped no statistical benefit from extra exercise, and actually gained slightly more weight than women who were couch potatoes. The study didn't address the “why,” but based on my experience in weight-loss counseling, women frequently complain that exercise makes them hungry, and consequently they end up losing control and eating much more than they do when sedentary.
Yet another thing to mention: Individual responses to exercise may vary, so if you are sure that exercise works for you there is no need to stop just because a study says it doesn't. In a nutrition research conference I organized last summer, even the exercise physiologists were finally admitting that exercise has little average effect on body weight, but they also stressed that some people may respond better to exercise than others, and that while the mean benefit appears very small, for individuals the effect of adding exercise will range from weight gain to modest weight loss.
Of course, this is not to say that exercise is bad. On the contrary, it’s essential to a healthy lifestyle—it has a range of physical and mental health benefits, and is often the only thing standing between us and disability in old age.
But just because exercise is important for health doesn't mean it is important for everything. Instead of spending an entire hour each day exercising, we might instead spend some of that time thinking about what we eat—which is key to preventing weight gain—and cooking our own food at home.
What else can you do to prevent weight gain as you pack on the decades? Other research studies point to two factors as particularly important to preventing age-related ballooning.
1. Avoid “disinhibited eating.” Disinhibited eating is a psychological term for taking casual opportunities to eat with abandon. Birthday cake, free hot dogs, and candy on a coworker’s desk are all opportunities for eating if you take them, and several research studies show that people who step up and take a helping will gain 20 or 30 pounds more as they age, compared to those who say “no thanks” and stick to their regular meals and snacks.
2. Accept that your calorie needs decline as you get older and that your eating patterns need to change. Depending on your individual characteristics, your calorie needs may decline anywhere from 500 to 1,000 calories per day between the ages of 20 and 70. That is a lot less food you need to eat to stay weight stable, and since you still need to get essential nutrients and feel full even if you need less calories, that means cutting out more junk and focusing on fresh, healthy foods that really fill you up.
Weight control is the national health crisis of our time and if we can help everyone who is overweight and obese lose just 10 pounds, we would have a phenomenal impact on health-care costs. We should put our effort where it will bring results: by focusing on calories and good weight-helping foods that fill us up and keep us healthy, rather than pushing exercise as the most important solution and then wondering why it isn't working.
Susan B. Roberts is professor of nutrition and professor of psychiatry at Tufts University and author of The "I" Diet weight-loss program. Weight loss on this program averages 16 pounds in eight weeks and 30 pounds in five months.