Ketones and Muscle Protein Synthesis

Ketones are natural substances normally produced by the body during prolonged fasting and starvation, or in response to a "ketogenic" diet to be used as fuel by the brain and muscles. Ketones are therefore similar to dietary proteins, carbohydrates and fats since they represent a source of energy for the body. In addition to serving as a source of energy, ketones have also been shown to stimulate increased rates of muscle protein synthesis in humans. The ingestion of dietary protein is well established to stimulate an increase in the rate of protein synthesis in skeletal muscle. The rate of muscle protein synthesis can be maximized following the intake of 20g of protein. As a result, smaller doses of protein (i.e. 10g) represent a sub-optimal dose of protein because there is still room for improvement concerning muscle protein synthesis. Recently ketone-containing food products have become available that elevate ketone levels in the body without the need for ketogenic diets or prolonged fasting. Therefore, the purpose of this study is to measure skeletal muscle protein synthesis rates after ingesting the following: Ketone monoester Ketone monoester supplemented with sub-optimal dose of whey protein Sub-optimal dose of whey protein It is hypothesized that muscle protein synthesis rates will increase following the ingestion of a ketone-containing beverage. Further, muscle protein synthesis rates will be enhanced when the ketone-containing beverage and sub-optimal protein dose are taken together.

Ketone monoester supplement (R)-3-hydroxybutyl (R)-3-hydroxybutyrate based on participants' body weight (0.36g/kg body weight) and carbohydrate control.

Ketone monoester supplement (R)-3-hydroxybutyl (R)-3-hydroxybutyrate based on participants' body weight (0.36g/kg body weight) and 10g of whey protein.

Ketone monoester supplement (R)-3-hydroxybutyl (R)-3-hydroxybutyrate based on participants' body weight (0.36g/kg body weight) Isocaloric carbohydrate control: dextrose + vanilla flavouring

Ketone monoester supplement (R)-3-hydroxybutyl (R)-3-hydroxybutyrate based on participants' body weight (0.36g/kg body weight) 10g Whey Protein L-[ring-2H5]-phenylalanine tracer (enriched to 4%)

Isocaloric carbohydrate control: dextrose + stevia 10g Whey Protein L-[ring-2H5]-phenylalanine tracer (enriched to 4%)

The use of Western blots to measure the phosphorylation status of signaling molecules involved in protein synthesis ie. mTOR, p70S6k, 4E-BP1

Inclusion Criteria: Male Aged between 18-35 years inclusive Healthy, moderately active BMI < 30 kg/m2 and > 18.5 kg/m2 Having given informed consent Exclusion Criteria: Presence of any identified metabolic or intestinal disorders Use of tobacco products Allergies to milk proteins (whey or casein) Lactose intolerance Phenylketonuria (PKU) A history of neuromuscular problems Previous participation in amino acid tracer studies Adherence to a strict vegetarian or vegan diet Current use of ketone supplements or adherence to a ketogenic diet Use of medications known to affect protein metabolism Diagnosis of Diabetes Engagement in sports or physical exercise 5 or more days per week