Does overeating on a keto diet help build muscle?

Ketogenic diets^[1] induce a chronic reliance on ketone bodies as an energy source, which results in a metabolic state known as ketosis^[2]. Depending on the extent of ketosis one wishes to achieve, protein and fat intake can be variable, but carbohydrate restriction is mandatory and usually kept under 50 grams per day.

Ketogenic diets result in a metabolic shift toward reliance on ketones and fatty acids for fuel, lower glucose oxidation, decreased circulating insulin concentrations, and a reduction in the rate of muscle glycogen utilization during exercise, which are believed by some to have beneficial effects on body composition^[3]. On the other hand, ketogenic diets are known to impair high-intensity exercise performance^[4], which could have negative effects on body composition in people who perform resistance training with the hopes of increasing muscle mass, since they would theoretically not be able to provide as great of an anabolic stimulus.

Although there is quite a bit of research on the effects of ketogenic diets on bodyweight^[5] in people who are overweight or obese, and on managing conditions like type 2 diabetes^[6] and epilepsy^[7], few studies to date have examined how ketogenic diets impact body composition in resistance-trained participants. Moreover, until recently, no studies had been published that looked at the body composition effects of overfeeding while on a ketogenic diet.

The study under review attempted to fill these knowledge gaps by investigating how a ketogenic diet would affect the body composition of resistance-trained men under hypercaloric conditions.

Ketogenic diets are very low carbohydrate diets that induce a metabolic condition called ketosis. While the impact of ketogenic diets on body composition is a growing area of research, little is known about how hypercaloric ketogenic diets would affect body composition in participants undergoing resistance training. The study under review sought to fill this knowledge gap.