D Briskey^{1, 2}, RA Skinner¹, Haibo Zhang^{3, 4}, Zhixian Chen⁴, A Rao^1,

Protein supplementation is a practical and cost-efficient strategy to meet protein needs, essential for muscle maintenance and growth, especially during exercise. A critical factor in assessing protein sources is their impact on muscle protein synthesis. This study aimed to compare the effectiveness of yeast protein, whey protein, and a placebo when combined with resistance exercise, focusing on body composition, strength, and endurance outcomes. Seventy-nine participants consumed either 40 g of AnPro® yeast protein, whey protein, or a placebo (maltodextrin) twice daily for 8 weeks. Simultaneously, they engaged in thrice-weekly resistance training and underwent DEXA scans at baseline and week 8. Results showed increases in total mass, BMI, and strength for all groups compared to baseline, with both yeast and whey protein groups exhibiting gains in trunk and total lean mass. Additionally, the AnPro® group experienced reduced diastolic blood pressure and enhanced muscle endurance in bench press performance at 80% 1-RM, while the whey protein group showed improved muscle endurance in leg press performance. Furthermore, the whey protein group displayed a significant reduction in trunk fat mass compared to the placebo group. Subgroup analysis, focusing on individuals with low protein intake, revealed significant increases in lean mass and muscle strength, particularly in the 1-RM bench press, for both yeast and whey protein groups compared to placebo. These findings emphasize the effectiveness of yeast and whey protein in enhancing lean mass and strength compared to a placebo, particularly among individuals with low dietary protein intake.

yeast protein, resistance exercise, lean mass, strength, protein supplementation