Available at: https://digitalcommons.calpoly.edu/theses/3143
Date of Award
8-2025
Degree Name
MS in Nutrition
Department/Program
Food Science and Nutrition
College
College of Agriculture, Food, and Environmental Sciences
Advisor
Angelos Sikalidis
Advisor Department
Food Science and Nutrition
Advisor College
College of Agriculture, Food, and Environmental Sciences
Abstract
Plant-based diets continue to grow in popularity, but effective plant-based protein powder that produces similar effects to the gold standard of protein supplementation, whey protein, has yet to be developed. Leucine is a branched-chain amino acid (BCAA) that has become popular for its effects in enhancing and supporting muscle protein synthesis. Muscle protein synthesis can contribute to a more desirable body composition in terms of improving insulin sensitivity and preventing diseases such as type 2 diabetes mellitus. Leucine is notably lower in plant-based food products compared to animal-based counterparts, contributing to the lack of efficacy in plant-based protein powders’ capacity to produce results akin to animal-based protein powders. In this pilot study, eighteen college-aged females consumed either a rice protein (RP), amino acid/leucine-enhanced rice protein (RP+), or whey protein (WP) powder once a day for 8 days. Blood amino acid profile, body composition, dietary patterns, urinary nitrogen, urinary specific gravity, and nitrogen balance were assessed and compared between the three treatment groups. Results revealed significant differences from baseline to post-intervention for glucose, urinary specific gravity, nitrogen balance, total amino acids, essential amino acids, and leucine across all participants. Furthermore, differences between treatment groups were observed for total amino acids, essential amino acids, and leucine content, specifically between RP and both RP+ and WP groups. No significant difference was revealed between the RP+ and WP groups, illustrating the successful fortification of plant-based protein to achieve similar results to whey protein in terms of anabolic and MPS potential from improved amino acid profiles in the blood.