Exercise or Diet: Which Is More Important?

Ideally, a weight loss regimen entails a change in eating habits and a workout routine. However, many people get overwhelmed when attempting to make too many changes at once and end up doing nothing at all. If that describes you, you're probably wondering if you're better off going on a diet or starting an exercise program in order to lose weight. While most diet and weight loss sites will tell you that diet is the most important factor in losing weight, we disagree. If you're only up to doing one of the two, exercise beats dieting for permanent weight loss. Keep reading to learn why.

Dieting without Exercising Can Make You Fatter

If you go on a diet without increasing your activity level, you are lowering your metabolic rate. This is especially true for very low calorie diets, but it starts to happen even on a standard 1200 calorie a day diet if you stick with it longer than a week or two. But it gets worse. You will also lose lean muscle mass in addition to fat. Again, the lower your calorie intake, the greater the loss of muscle tissue. Obviously muscle loss is undesirable for a number of reasons, but it's particularly troubling from a weight loss perspective because a higher percentage of lean muscle mass equals a higher basal metabolic rate (BMR). In other words, the more muscle you have, the more calories your body burns even when resting.

Post-diet weight gain is usually attributed to dieters returning to their old eating habits, and while that's certainly an important factor, the individual's lowered metabolic rate also plays a key role. In extreme cases, individuals have started gaining weight on as little as 1000 calories a day after prolonged periods of crash dieting without significant muscle-building exercise. The loss of lean muscle mass and the lowered metabolic rate that goes with it are the reason many people end up heavier and flabbier (i.e., with a higher percentage of body fat) than they were before going on a diet.

Is Exercise without Dieting Sufficient to Lose Weight?

Numerous studies show that even a relatively mild form of exercise such as walking results in weight loss without a change in eating habits provided you do enough of it. How much is enough? It depends on the type of exercise and your goals. Walking vigorously for thirty minutes a day or twenty to thirty minutes of weight training or cardio three or four times a week are sufficient to produce slow, steady weight loss without changing your eating habits one bit. Better yet, your weight loss will consist entirely of fat loss without the large amounts of fluid and muscle mass that are lost when dieting. Indeed, you will be adding lean muscle mass, which means your metabolic rate increases.

Regular Exercise Can Change Eating Habits

While regular exercise will result in weight loss even if you eat exactly the same way you do right now, working out often has the welcome side effect of changing your eating habits for the better. Melanie Landers is a classic example of this phenomenon. "Every popular diet that came out in the last ten years--you name it, I've tried it," says Landers. In every case, she ended up gaining back the weight she lost, and then some. Finally, Melanie had enough. Instead of embarking on yet another weight loss diet, her new goal was simply to stick to a regular exercise routine. She started by exercising every other day and alternating between cardio and weightlifting workouts.

"After a couple of weeks something interesting began to happen. I became more conscious of what I ate. It was like, I just worked real hard to burn 400 calories; do I really want to eat that piece of pie and put it all back?" Sometimes the answer to that question is still yes. "If I'm at a restaurant with an amazing desert selection or my mom has made her incredible pecan pie, I don't deny myself. After all, it's not like I'm on a diet." But Melanie found herself making healthier food choices in her everyday life. "When you start taking pride in your body, you're less likely to fill it with junk food," she says.

Another reason people who exercise regularly often improve their eating habits is that exercise reduces stress, and stress is a major factor in overeating and weight gain. Additionally, exercise--especially intense exercise--results in endorphin release and boosts serotonin levels, both of which can make you feel happier. In fact, exercise is often prescribed as a treatment for mild depression. And since many people are overweight due to "emotional eating," regular exercise can have a profound effect on eating habits.

If changing your diet and starting an exercise routine is more than you can handle, just focus on getting into the habit of working out for now. Once you start exercising regularly, you may find that your eating habits improve automatically.