Weight-Loss Tips

1. Dieting trumps exercising

We hear a lot that a little exercise is the key to weight loss – that taking the stairs instead of the elevator will make a difference, for instance. But in fact it’s much more efficient to cut calories, says Samuel Klein, MD at Washington University’s School of Medicine. “Decreasing food intake is much more effective than increasing physical activity to achieve weight loss. If you want to achieve a 300 kcal energy deficit you can run in the park for 3 miles or not eat 2 ounces of potato chips.” It’s as simple as that. Some studies have borne out this dichotomy, pitting exercise against diet and finding that participants tend to lose more weight by dieting alone than by exercise alone. Of course, both together would be even better.

The problem is that when you rely on exercise alone, it often backfires, for a couple of reasons. This is partly because of exercise’s effects on the hunger and appetite hormones, which make you feel noticeably hungrier after exercise. “If you walk briskly for an hour and burn 400 kcal,” says Klein, “and then have a beer and a slice of pizza afterwards because the exercise made you feel hungry…you will eat more calories than you have burned.” It may not always be beer and pizza, but people do tend to naturally compensate for the calories they expend.

2. Exercise can help fix a “broken” metabolism, especially during maintenance

“People used to come into the doctor’s office and say, ‘My metabolism is broken!’” says James Hill, PhD, at the University of Colorado. “We never had any evidence that it actually was, until recently. We were wrong – it was!” While exercise may not be as important for weigh loss as calorie restriction, as Hill says, it’s important in another way: It begins to repair a broken metabolism.

“A lot of what we know in this area comes from NASA, of the bed-rest studies,” he says. “Within a couple of days of non-activity, the metabolism becomes inflexible. You start moving again, and it does start to change.” Your metabolism may not ever go back to “normal” (more on this below), but the evidence indicates that it can indeed pick up again, in large part through moving your body every day.

3. You’re going to have to work harder than other people – possibly forever

Though exercise can help correct a metabolism that’s been out of whack for a long time, the grisly reality is that it may not ever go back to what it was before you gained weight. So if you’ve been overweight or obese and you lose weight, maintaining that loss means you’re probably going to have to work harder than other people, maybe for good. “The sad thing,” says Hill, “is that once you’ve been obese or not moving for some time, it takes a little more exercise to maintain. It doesn’t come back to normal.” It’s not a pretty reality to face, but coming to grips with it is important, he says, so that you won’t get frustrated when you discover that you have to do more work over the long term than your friend who was never overweight.

Building muscle can help your body burn a few more calories throughout the day, but it’s also likely that you’ll have to work harder aerobically in the long run. “It’s not fair, but that’s the way it is,” adds Hill. “Once you understand it, though, you know it and it’s better. Because you can work with it.”