The Impact of Ketogenic Diet on Hypertrophic Signalling and Body Composition in Resistance-Trained Males

The ketogenic diet (KD) is a nutritional approach characterized by high fat, adequate protein, and restricted carbohydrate intake (5% of total daily intake) that induces a state of physiological ketosis. However, metabolic adaptations may potentially interfere with muscle hypertrophy signaling pathways. Thus, this study sought to assess the impact of KD on muscle adaptation to resistance training (RT) in trained, healthy male subjects. Nineteen subjects (28.7 ± 8.1 years) were randomized to either a ketogenic (KD, n=10) or a control diet (CD, n=9), similar in terms of calories (35 kcal/kg body weight) and protein intakes (2 g/kg body weight). During the four-week intervention, participants followed the same RT protocol. Before and after the intervention period, hormonal profiles (IGF-1, insulin, total and free testosterone), resting metabolic rate, body composition (BIA and DEXA), and muscle strength (1RM) were assessed. Muscle biopsies were obtained at rest and at 6 and 24 hours after a single RT session to evaluate the phosphorylation of regulatory signaling proteins (i.e., Akt, rpS6, 4E-BP1) via Western blotting. Preliminary findings show that a pronounced fat loss was reported in KD (-8.06% vs +0.84%) while lean soft mass was not significantly affected in both groups. At rest, differences in hormones profile were not reported and, acute response after a single bout of RT was also comparable between groups. In conclusion, four weeks of KD combined with RT seem to improve body composition without impairing anabolic response and post-exercise hypertrophic signaling.