sfgate.com Web Search by YAHOO! Businesses

Do You Lose Weight Faster by Eating Less or Exercising?

by Gina Battaglia
    Dieting promotes faster weight loss, but exercising helps you keep weight off.


    loss weight image by gajatz from Fotolia.com

    Weight loss is simplistic in theory. If you reduce more calories than you normally burn, by either reducing your food intake or increasing your exercise, you will lose weight. Eating fewer calories will lead to faster weight loss in most people because substantial calorie deficits through exercise would require a large volume of training. However, exercise can help maintain muscle mass and thus sustain a high metabolic rate, ensuring a greater proportion of fat loss and perhaps making it easier to maintain the weight loss.

    Calorie Deficit

    Losing a pound of body weight requires that you take in or spend 3,500 calories less than you usually burn. Therefore, to lose a pound per week through diet and exercise, you would have to average a 500-calorie deficit per day by reducing your food intake, increasing your exercise, or doing some combination of the two. However, drastic long-term calorie restriction is difficult to maintain and may slow your metabolism by decreasing muscle mass while high volumes of exercise may increase your appetite and thus offset any calorie deficit.


    A reduced-calorie diet is instrumental to losing a significant amount of weight in a short period of time. A 1997 study published in the "International Journal of Obesity, " which analyzed 493 weight loss intervention studies over a 25-year period, showed that diet and diet plus exercise interventions resulted in approximately four times the weight loss over a 13- to 15-week period compared to an exercise-only intervention. Furthermore, both groups with a reduced-calorie diet lost weight at an average rate of about one kilogram per week, whereas the exercise-only group lost 0.2 kilograms per week. Although exercise increases calorie burn rate, it may also increase appetite and decrease physical activity levels during the remainder of the day in some individuals, thereby offsetting calorie deficit.


    Although a reduced-calorie diet is most effective for short-term weight loss, exercise in addition to a calorie deficit may promote long-term weight loss better than diet alone. While the analysis of 493 weight loss interventions showed a similar rate of weight loss during the initial weeks, the individuals who went through the diet plus exercise intervention maintained more of the weight loss compared to the individuals who only dieted. According to a 1994 analysis of multiple weight loss studies published in the "International Journal of Obesity," exercise training preserves more muscle mass during a reduced-calorie diet, compared to dieting alone. Because muscle has a higher metabolic rate than fat, maintaining muscle mass will keep your metabolism elevated and perhaps make it easier to keep excess weight off.


    The efficacy of diet or exercise in promoting weight loss will likely depend on how many calories you are currently consuming and the amount of exercise you are currently doing. For example, if you are already doing a large volume of exercise training, you probably cannot realistically increase your exercise much more and would benefit from adjusting your diet. Conversely, if you do not have a high calorie intake and do not exercise, increasing activity level along with making minor dietary adjustments is a better strategy for you.

    About the Author


    Photo Credits

    Suggest a Correction

    Have Feedback?


    © 2013 Hearst Communications Inc.