RW: Is consuming fewer calories the best way to lose weight?
YES: If someone wants to lose weight, restricting calories will do it, but he'd be healthier if he'd exercise as well. In a large study published in 2010, researchers looked at a group of people who only dieted, and another group who dieted and exercised. Both groups maintained exactly the same calorie deficit each day, and therefore lost the same amount of weight. But the diet-plus-exercise group experienced much better changes in certain health markers. Also, resistance exercise can build muscle, and more muscle can help you burn more calories even when you're at rest. And exercise is especially good at helping you keep the weight off once you lose it. So if there's one message here for people who are adamant about trying to lose weight, it's that you may get pounds off with dieting but to keep them off you're going to have to exercise. You'll be healthier for it, too.
RW: Do the benefits of exercise matter more than losing weight?
YES: Physical activity can lower your risk of cardiovascular disease, regardless of your weight. Whether you're talking about boosting good HDL cholesterol, lowering bad LDL cholesterol, reducing blood pressure, and so forth—all these can be improved with exercise, even if you don't lose weight. And this results in a lower cardiovascular-disease risk. Physical activity seems to have a profound effect on overall mortality risk as well—again, regardless of your weight.
NO: Exercise can improve your health, but you can list more than 50 medical conditions—from diabetes to arthritis to acid reflux to sleep apnea to certain cancers—that result from complications from carrying excess weight. Even losing five or 10 pounds will lower your risk of developing these issues and improve your health.
RW: So is it more important to exercise than to lose weight?
YES: It's been shown that about twice as many people achieve their exercise goals compared with their weight-loss goals. Weight loss may happen with exercise, but it may not. Over the past 30 years, millions of Americans have attempted to lose weight. Yet we're heavier now than ever. Something's not working. So instead of emphasizing losing weight, let's emphasize getting fit. Never mind losing 30 pounds, how about walking for 30 minutes?
NO: I'd like to see exercise—along with a healthy diet—promoted as a way to solve the obesity epidemic. I run a weight-management clinic, and I've been trying to get patients to lose weight. I've found it's actually not that hard to change people's behavior—their diet and physical activity, in this case. Americans simply need to exercise more and lose weight.