A myth: Exercisers eat better

With those New Year’s diet and exercise resolutions fresh in your mind, it might be important to know that it’s a myth that people who work out eat better.

In a 16-month federally funded study, researchers from the University of Kansas and University of Colorado put to the test the popular notion that people improve their eating habits when they exercise.

They recruited 74 overweight to moderately obese people ages 17 to 35 who were sedentary, otherwise healthy and didn’t smoke. Members of one group exercised for 45 minutes five times a week under researchers’ supervision and were told to maintain their normal caloric intake. Members of the other group were told to maintain their usual physical activity and eating habits, which periodically were observed in the college cafeteria.

At the end of the study, the researchers found no change in the amount of fat, protein and carbohydrates the exercisers and nonexercisers consumed. Furthermore, they found that people harbored the illusion that they could eat what they wanted as long as they were exercising.

“The general public believes that everyone reduces fat and increases carbohydrate intake automatically when exercising, but this spontaneous change to a healthy diet didn’t happen,” lead author Joseph E. Donnelly said in a recent statement. Donnelly is a professor of health, sport and exercise sciences at the University of Kansas Center for Physical Activity and Weight Management.

The study, funded with $2.4 million from the National Institutes of Health, appears in the November issue of the American Journal of Clinical Nutrition.