Resistance to body fat gain in 'double-muscled' mice fed a high-fat diet

Objective: To determine if myostatin deficiency attenuates body fat gain with increased dietary fat intake. Methods: Normal and myostatin-deficient mice were fed control (8-10 kcal % fat) and high-fat (HF) ( 45 kcal % fat) diets for a period of 8 weeks, starting at 2 months of age. Body composition, including percent body fat, lean mass, and fat mass, were measured using DXA. Serum adipokines were measured using a Beadlyte assay. Results: Two-factor ANOVA revealed significant treatment x genotype interactions for body fat (g), percent body fat, and serum leptin. The HF diet significantly increased body fat, percent body fat, and serum leptin in normal mice but not in myostatin-deficient mice. Conclusion: Loss of myostatin function not only increases muscle mass in animal models but also attenuates the body fat accumulation that usually accompanies an HF diet.