Public Release: 

Imbalances In Diet Can Reduce Testosterone, Muscle Strength

Penn State

University Park, Pa. -- Imbalances in the diet can reduce levels of testosterone, a hormone necessary to increase the size and strength of muscles.

A Penn State study published in the Journal of Applied Physiology, showed a positive correlation between diet and testosterone levels, notes the March issue of the Penn State Sports Medicine Newsletter.

"Some people recommend high-carbohydrate, low-fat diets," says Jeff Volek, M.S., R.D., a researcher at Penn State. "While this diet has some advantages, high-carbohydrate intake at the expense of other nutrients such as fat may cause a drop in testosterone. The same is true if there is too much protein in the diet and too few carbohydrates."

The effects of overtraining, combined with a low-fat diet, can compound the problem of low-testosterone concentrations, according to the Sports Medicine Newsletter.

The public has come to believe that the lower the fat, the better in all circumstances," says William J. Kraemer, Ph.D., a member of the newsletter's editorial board and one of the study researchers. "Our study shows that a balance of nutrients is needed, based on the goals of training and nutrition."

The Penn State study involved 12 men in an exercise routine that included bench presses and jump squats. The study showed a positive correlation between dietary fat and both pre-exercise and post-exercise, resting testosterone levels.

EDITORS: The Penn State Sports Medicine Newsletter can be reached at (814) 865-7110 or at its home page at


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