Ketogenic Diets: A Molecular Monkey Wrench

Inhibit mTOR, Insulin, IGF-1 and Muscle Growth

- Michael J. Rudolph, Ph.D

Nutrition is arguably the most important component of an athlete or bodybuilder’s training regimen. A precise and effective nutritional diet plan produces a biochemical environment that promotes the most efficient muscular adaptations to resistance or endurance exercise. Throughout the years, bodybuilders and athletes have tried to improve their physiques by implementing the ketogenic diet that is high in fat and low in protein and carbohydrate. The fundamental idea behind the ketogenic diet, besides being hypocaloric, is to persuade the body to burn fats rather than carbohydrates or protein due to the lack of carbohydrate and protein in the diet. The excessive fatty acid oxidation in the liver leads to the inevitable conversion of accumulated fatty acid oxidation intermediates into ketone bodies, which were suspected to possess appetite-suppressant properties— thus further facilitating caloric restriction and loss of body fat.

LOSS OF MUSCLE MASS AND STRENGTH

While ketogenic diets tend to stimulate fast weight loss, one of the major drawbacks of the ketogenic diet is that a significant percentage of that bodyweight lost is muscle mass. This negative aspect of the ketogenic diet occurs despite the fact that the body typically prefers to burn either carbohydrates or fat for energy instead of muscle protein, even during times of reduced caloric consumption. For some reason, ketogenic diets generate a greater than normal preference for muscle protein as an energy source during hypocaloric consumption. This phenomenon appears to be partially due to the poor regulation of the all-important nutrient-sensing molecule mTOR from the low carbohydrate ketogenic diet.