V. Vidić, V. Ilić, L. Toskić, N. Janković and D. Ugarković (2021). 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. Clinical nutrition (Edinburgh, Scotland), 40(4), 1495-1502. https://doi.org/10.1016/j.clnu.2021.02.028

PubMed 33743284

[Abstract]
BACKGROUND & AIMS: 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.

METHODS: 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.

RESULTS: 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).

CONCLUSIONS: Ketogenic diet with sustained hyper-ketonemia above 1 mol/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.