Protein supplementation is said to be one of the cost-efficient and practical strategies to meet protein needs for growth and exercise, and can help maximize muscle gain from resistance exercise. It facilitates faster recovery from stress-induced tissue damage and enhances performance output. Protein sources derived from animal products are generally recognized as the highest quality protein. However, altering the protein composition of a protein source can improve the protein quality. The yeast protein supplement the investigators will use in this study has a similar amino acid composition to whey protein, which is derived from an animal product, but it is produced more sustainably. The study aims to compare the effects of yeast and whey protein on muscle mass over 16 weeks.

This is a double-blinded randomized clinical trial of a 16-week nutrition intervention with yeast and whey protein in 72 people (36 per group; 18 male and 18 female) between the ages of 18 and 35, recruited from the University of Alberta campus, Edmonton, Canada. Consenting participants will be randomly assigned to one of two groups: whey protein or yeast protein by the study coordinator, who will not collect study outcome measurements or analyze the data.

The goal of the trial is to determine if consumption of 40 g per day of yeast protein produces similar effects to 40 g supplementation with whey protein. It is anticipated that daily yeast protein consumption will show similar gains in muscle mass and improvement in immune function, increased diversity in gut microbiota, and amino acid-derived metabolites compared to whey protein.

Inclusion Criteria:

• Participants must have the ability to read, understand, and sign an informed consent and must be willing to comply with study treatment and follow-up.
• Prior resistance training experience (defined as performing resistance exercises >1/week for the past 3 months or longer) to enable them to reach a large training stimulus relatively quickly and to avoid the longer phase of neuromuscular adaptations
• ≥18 years and <35 years of age

Exclusion Criteria:

• Diabetes, musculoskeletal disease, cancer, Crohn's disease, or any other acute or chronic condition that interferes (or the medication prescribed for those conditions) with muscle anabolism.
• Diagnosed with or being treated for heart disease, stroke, high blood pressure 130/80 mmHg or higher
• Pain/discomfort/pressure in the chest during activities of daily living or physical activity
• Pregnant or not on adequate contraception.
• A known hypersensitivity/allergy to ingredients in the supplements.
• Inflammatory bowel diseases
• Enrolment in any other clinical protocol or investigational study that may interfere with study procedures
• Taking antibiotics

Only researchers who have the training and experience to do the research (also known as "qualified researchers") will be allowed to use the data. IPD collected throughout the trail will be shared on request and with ethics approval after the study results have been accepted and published

IPD will be available for 15 yrs