Why Dieting Doesn’t Work for Athletes

Racing Weight - Running shoes and mixed fruits and vegetables on the floor

Racing Weight explains 6 simple ways athletes can lose fat without losing performance.

This article is from Racing Weight, Matt Fitzgerald’s proven weight-management program designed specifically for endurance athletes. 

Everyone knows what a diet is. Because dieting is so familiar and ubiquitous, we don’t usually define it, but if we wanted to do so anyway, we could describe it as the practice of adopting a set of dietary rules—which usually include reduced food intake or forbidden food types—for the sake of losing weight.

Performance weight management is rather different from dieting. It is best defined as an ongoing effort to improve endurance performance by optimizing body composition for racing through nutritional, as well as other, means. Successful performance weight management usually results in the loss of body fat and body weight, but not always, because this is not, in fact, the goal. Some athletes attain their optimal racing weight by gaining muscle, for example.

Dieting can be an effective way to lose weight. Men and women who follow a traditional weight-loss diet such as Weight Watchers (based on calorie restriction) or the Atkins diet (based on food-type prohibition) often lose weight quickly at first. Unfortunately, few dieters stick with their program long enough to reach their weight goal, and more than 80 percent of those who do reach that goal through dieting eventually gain back most or all of the weight they lost.

Many age-group endurance athletes use dieting to lose weight as well. But dieting is not really appropriate for endurance athletes. The goal of dieting— weight loss for its own sake—is not the proper goal for cyclists, runners, swimmers, and triathletes. Improved performance is the proper goal. While weight loss in endurance athletes is frequently associated with improved performance, it isn’t always. When endurance athletes lose weight through dieting, their performance often suffers. The main problem is that the typical weight-loss diet fails to supply enough energy to support hard training. Diets based on food-type prohibitions sometimes also deprive the body of specific nutrients—especially carbohydrate— that are needed to properly absorb a heavy training load.

In fact, many diets intended for nonathletes can lead to worsened body composition when athletes use them.

A number of years ago scientists at the American Institute of Cancer Research (AICR) analyzed the nutritional guidelines presented in four diet books that were then popular: Dr. Atkins’ New Diet Revolution, The New Beverly Hills Diet, Protein Power, and Suzanne Somers’ Get Skinny on Fabulous Food (Meinz n.d.). None of these diets was promoted as a low-calorie diet. Each of them had its own distinct “secret” to weight loss. The secret of the New Beverly Hills Diet, for example, was food combining, whereas the secret of the Atkins diet was, of course, low carbohydrate intake. But the AICR analysis revealed that any reader who strictly followed the guidelines of any one of these four diets would in fact find herself on a low-calorie diet. Any weight loss that a person achieved on one of these programs would be attributable to the large calorie deficit it created, not to its proposed secret.

Other research has shown that the various popular weight-loss diets are more or less equally effective for overweight individuals who stick with them (Dansinger et al. 2005). This is only to be expected since, again, all such diets work the same way despite their disparate packaging. Endurance athletes are able to create even larger calorie deficits and lose weight even faster on traditional low-calorie diets because their training increases the amount of calories needed to maintain their current body weight. The catch—and it’s a big one—is that large calorie deficits deprive the muscles of the fuel they need for optimal performance in workouts and for fast recovery between workouts.

Racing Weight explains 6 simple ways athletes can lose fat without losing performance. For athletes who do want a more traditional diet, Racing Weight Quick Start Guide offers a training plan and nutrition plan to lose weight quickly over a short period of time between training blocks.

Racing Weight is a proven weight-management program designed specifically for endurance athletes. Revealing the latest research and drawing from the best practices of elite athletes, coach and nutritionist Matt Fitzgerald lays out six easy steps to help cyclists, triathletes, and runners lose weight without harming their training.