Provided By: Berkeley Wellness

Many people fear that exercise will do just that, and that the calories they burn while exercising will be more than made up for by the extra food they'll eat. But most studies have found that people who exercise moderately tend to eat about the same as they would if they didn't work out--or only slightly more. Competitive athletes in strenuous training do eat much more than usual, but they almost always burn the extra calories. Remember, however, that even if you don't lose weight when you start exercising regularly, you're likely to become trimmer and fitter, since you'll build muscle and lose some body fat.

During the first hour or so after a workout, appetite tends to drop, especially if you exercise strenuously. But over the longer term, energy expenditure and intake tend to be in balance.

It's hard to generalize, however, about the effect of exercise on appetite. Appetite regulation is a complex process, involving insulin and blood sugar levels and a variety of hormones and other chemicals, as well as psychological factors. In addition, many variables come into play in the studies, such as whether the subjects were overweight or not, women or men, previously sedentary or athletes, as well as the frequency, duration, and intensity of their workouts. The studies also look at different time frames: food intake may be measured right after exercise, over the course of the day, or for several days or weeks. Short-term research can't evaluate the body's regulation and adaptation processes during a long-term exercise regimen.

A balancing act
If you're trying to lose weight, or at least not gain weight, exercise is your friend. Most studies comparing the roles of dieting (that is, reducing calorie intake) and exercise in weight loss have found that the greater benefit comes from the diet. To lose one pound, you need a 3,500-calorie deficit. You could get that by running four or five miles every day for a week (depending on how much you weigh and how fast you run), or else by cutting your calorie intake by 500 calories a day for a week. For most overweight people, the exercise would be harder than dieting, at least at first.

But combining exercise and diet may be easiest: jog four miles every other day and cut your calories by 250 a day and you'll lose that same pound in a week. Adding exercise to a low-calorie diet not only burns more calories, but also helps prevent the loss of muscle mass and the drop in metabolic rate that usually accompanies dieting. And once you're at your desired weight, exercise is an excellent way to stay there and prevent future weight gain.