A Pilot Study to Examine the Effect of Pea Protein on Limiting the Loss of Muscle Mass during Weight Loss: Study Design and Rationale

Objectives: Weight loss has physiological benefits for people with obesity; however, the accompanying loss of muscle mass may pose additional health risks.High protein diets are effective for retaining muscle mass during weight loss, but it has yet to be determined if all protein sources are beneficial.This paper describes the design and rationale of a randomized, double-blinded, comparator-controlled single-site clinical trial to investigate the effects of pea protein, whey protein, or maltodextrin supplementation on muscle mass and functionality in males and females with obesity undertaking a weight loss regimen.Methods: Sixty obese participants will be randomized to consume pea protein, whey protein, or maltodextrin for 12 weeks as part of a calorie-restricted diet.The primary endpoints are changes in muscle mass and functionality as measured by dual-energy x-ray absorptiometry and physical performance tests (hand grip strength, gait speed), respectively.Secondary endpoints include changes in body weight and composition, resting energy expenditure and measures of inflammation, metabolic and cardiovascular function, as well as 24 h activity patterns and food intake over time.Conclusion: This trial will provide novel and important findings on how these different protein sources affect the loss of muscle mass expected to occur during weight loss.Furthermore, this research may support the utility of pea protein as a functional plant-based ingredient for promoting favourable changes in body composition during weight loss.The study is registered on Clinicaltrials.gov(NCT04123938).