The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


Fitness vs. fatness: diet vs. exercise for weight loss

Posted in
Live well

Monday, Jan 25, 2010

The diet vs exercise debate for weight loss continues as TV and web sites market their weight loss programs.  A recent study1 performed at Louisiana State University examined the benefits of losing weight by diet only and combined diet plus exercise compared to a control group.  The purpose of the study was to determine if dieting plus exercise provides more health benefits than dieting alone.  Thirty-six healthy male and female, healthy, overweight participants (average age of 39 years) were assigned to either a control, diet, or diet and exercise group.  The diet only group reduced their caloric intake by 25%.  The combined diet and exercise group decreased caloric intake by 12.5% and burned another 12.5% of calories during supervised exercise sessions.  They were allowed to select their own exercise intensity.  Then exercise time was adjusted until they had burned the required number of calories.  The control group was placed on a diet which allowed them to maintain their current body weight.  Researchers measured fitness level, belly fat, blood pressure, cholesterol levels, insulin sensitivity and weight loss before and after 6 months of participation in the study.     Both the diet and diet plus exercise groups lost the same amount of weight, pounds of fat, and belly fat.  The diet plus exercise group increased fitness level by 22% with no change in the diet or control groups.  Total and bad cholesterol (LDL-cholesterol) decreased significantly in the diet plus exercise group only.   Good cholesterol levels increased significantly in all three groups including the control group.  However, blood pressure and insulin sensitivity improved in the diet plus exercise group only.      The results of this study show that losing weight through a combination of diet and exercise provides additional benefits over diet alone. 

These findings are consistent with the fact that both fitness and fatness affect cardiovascular disease risk.  Based on data from this study and a previous study2, 10-year risk of cardiovascular disease was reduced by 29% in the diet group and by 38% in the diet plus exercise group.  This research suggests that losing weight through a combination of diet and exercise provides more health benefits than diet alone.  Another important reason to include exercise as part of a weight loss program was addressed in the Stand Up and Eat blog in August, 2008.  It reported that women who lost 10% or more of their initial body weight were more likely to keep it off after two years if they exercised.  Those who exercised an average of 275 minutes per week (40-55 minutes of exercise 5 days/week) were the most successful in keeping their weight off.  Studies support the need to include both caloric restriction and exercise for optimal weight loss and weight maintenance.   

1.  Larson-Meyer, D.E., Redman, L., Heilbronn, L.K., Martin, C.K. & Ravussin, E. (2010). Caloric Restriction with or without Exercise: The Fitness versus Fatness Debate. MSSE, 42, 152-159. 2.  Lefevre, M., Redman, L.M., Heibronn, L.K. et al. (2009). Caloric restriction alone and with exercise improves CVD risk in healthy non-obese individuals. Atherosclerosis. 203(1), 206-213.