COM/155
Exercise vs. Diet in Weight Loss
INTRODUCTION
It is estimated that 55% of the adult population in the United States are either obese or overweight (National Institutes of Health, National Heart Lung, and Blood Institute, 1998). Obesity substantially increases an individual’s risk of suffering from chronic diseases such as hypertension, coronary artery disease, and diabetes. Those with excess fat in the abdominal area are at increased health risk (National Institutes of Health, National Heart Lung, and Blood Institute). In an attempt to define the role of exercise in the treatment and prevention of obesity, the American College of Sports Medicine (ACSM) held a scientific roundtable to address this subject. Following the meeting, several consensus statements regarding physical activity and public health were released. Two statements are of particular interest to the applied exercise professional. The first statement declares that the addition of exercise to a diet with restricted caloric intake promotes fat loss, while maintaining fat free mass. The second statement claims that physical activity, without caloric restriction, minimally if at all affects fat loss. The statements suggest that to optimize weight loss, a combination of diet and exercise is best, and that exercise alone will not suffice. Although it is well established that a regimen of diet and exercise is the best way to control body weight, a recent review by Ross, Freeman, and Janssen (2000) challenges ACSM’s statement that exercise alone is not an effective method of weight loss. This review suggests that the studies this statement was based upon do not effectively compare caloric restricting programs to increased energy expenditure programs. They conclude that if these factors were equal, exercise alone can be as effective as caloric restriction for weight loss. The purpose of this article is to present Ross et al.’s argument contrasting the ACSM consensus
References: Grundy, S.M., G. Blackburn, M. Higgins, R. Lauer, M. Perri, D. Ryan. Roundtable Consensus Statement: Physical activity in the prevention and treatment of obesity and its comorbidities. Med. Sci. Sports Exerc. 31: S502-S508, 1999. Hagan, R.D., S.J. Upton, L. Wong, and J. Whittam. The effects of aerobic conditioning and/or caloric restriction in overweight men and women. Med. Sci. Sports Exerc. 18:87-94, 1986. National Institutes of Health, National Heart, Lung, and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report. Obes. Res. 6(Suppl 2), 1998. Pate, R.R., M. Pratt, S.N. Blair, W.L. Haskell, C.A. Macera, C. Bouchard, D. Buchner, W. Ettinger, G.W. Heath, A.C. King, et al. Physical activity and public health. A recommendation for the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA. 273:402-407, 1995. Ross, R., D. Dagnone, P.J.H. Jones, H. Smith, A. Paddags, R. Hudson and I. Janssen. Reduction in obesity and related comorbid conditions after diet-induced weight loss or exercise-induced weight loss in men: A randomized controlled trial. Ann. Intern. Med. 133:92-103, 2000 Ross, R., and I. Janssen. Is abdominal fat preferentially reduced in response to exercise-induced weight loss? Med. Sci. Sports Exerc. 31: S568-S572, 1999. Ross, R., J.A. Freeman, and I. Janssen. Exercise alone is an effective strategy for reducing obesity and related comorbidities. Exerc. Sport Sci. Rev. 28: 165-170, 2000. Sopko, G., A. Leon, D. Jacobs, N. Foster, J. Moy, K. Kuba, J. Anderson, D. Casal, C. McNally, and I. Frantz. The effects of exercise and weight loss and plasma lipids in young obese men. Metabolism. 34:227-236, 1985.