Effects of calorie restricted low carbohydrate high fat ketogenic vs. non-ketogenic diet on strength, body-composition, hormonal and lipid profile in trained middle-aged men

Abstract

The aim of this paper was to investigate and compare the effects of two iso-energetic hypo-caloric ketogenic hyper-ketonemic and non-ketogenic low carbohydrate high fat high cholesterol diets on body-composition, muscle strength and hormonal profile in experienced resistance-trained middle-aged men. Twenty non-competitive experienced resistance-trained middle-aged men were on the supervised calorie maintenance western diet and resistance-training regimen for 4 weeks and then divided into ketogenic and non-ketogenic groups for 8 weeks period. Keto bodies (β-hydroxybutyrate) levels were measured weekly, testosterone and insulin biweekly, strength and body-composition monthly, lipid profile and blood sugar level at the beginning and at the end of the study. Both groups lost a similar amount of lean body mass and fat tissue (from F=248.665, p<0.001 to F=21.943, p=0.001), but preserved maximal upper and lower body strength (from F=1.772, p=0.238 to F=0.595, p=0.577). Basal testosterone and free testosterone increased (from F=37.267, p=0.001 to F=16.261, p=0.005) and insulin levels decreased significantly in both groups (F=27.609, p=0.001; F=54.256, p<0.001, respectively). No differences in lipid profile and blood sugar level were found (from F=4.174, p=0.058, to F=0.065, p=0.802). Ketogenic diet with sustained hyper-ketonemia above 1mol/l has the same impact as low carbohydrate non-ketogenic diet on muscle strength, body-composition, and hormonal and lipid profile in hypo-caloric dietary conditions in strength-trained middle-aged men.