Purpose: To evaluate adherence, tolerability, and total protein intake in bariatric surgery patients provided with ready-to-drink protein supplements, and to evaluate the effects of supplementation on body composition, metabolism, and health outcomes.

Participants: Patients scheduled to under go bariatric surgery aged 18-70 years old. Participants will be included if they agree to comply with the study protocol, are free of medical conditions that may contraindicate participation, and do not plan to become pregnant during the study.

Procedures (methods): Participants will complete five laboratory visits for the current study (pre-screening (visit 1), baseline testing (visit 2), and return visits at 3 weeks (visit 3), 12 weeks (visit 4), and 24 weeks (visit 5) post-surgery). The treatment group will be given a 12 week supply of a high protein, low-carbohydrate, low-fat supplement to be taken once daily during days 3-7 post-surgery, and twice daily weeks 2-12. The treatment group will follow standard of care recommendations put forth by the physician-nutritionist team, but using the provided protein supplement to meet recommendations. The control group will be asked to follow the standard of care recommendations from the physician-nutritionist team.

The primary study endpoints will be adherence, tolerability, and total protein intake in bariatric surgery patients provided with a 12-week supply of ready-to-drink protein supplements. Secondary outcomes will evaluate the effect of a protein supplement on body composition (lean mass, fat mass, percent body fat, visceral fat, muscle thickness), resting metabolic rate, clinical and endocrine blood values, functional fitness, and responses to questionnaires evaluating mood, satiety, functional independence, and health related quality of life.

Inclusion Criteria:

• Participant is scheduled for weight loss surgery
• Participant agrees to abstain from extraneous supplementation with creatine, β-hydroxy β-methylbutyrate, carnosine, beta-alanine, taurine, or any other supplement or prescription drug that may significantly influence body composition or metabolic rate
• Participant has provided written and dated informed consent to participate in the study
• Participant is willing and able to comply with the protocol
• Participant agrees to abstain from using caffeine, tobacco, and alcohol for at least 24 hours before testing days
• Participant agrees to abstain from exercise 24 hours prior to each testing visit
• Participant is not currently pregnant and does not desire to become pregnant in the next six months

Exclusion Criteria:

• Physicians on the research team believe that a pre-existing condition may influence participant safety or study outcomes, including previously diagnosed cardiovascular, metabolic, renal, hepatic, or musculoskeletal disorders
• Participant is using, or has used one of the following dietary supplements within 8 weeks prior to enrollment: creatine, β-hydroxy β-methylbutyrate, carnosine, beta-alanine, taurine, or any other supplement or prescription drug that may significantly influence body composition or metabolic rate
• Participant is in, or has participated in another clinical trial within 4 weeks prior to enrollment
• Participant is pregnant or plans on becoming pregnant
• Participant has a known allergy or sensitivity to any ingredient in the test product (determined from health history questionnaire)