Inclusion Criteria:
1. Subject is greater than or equal to 65 years of age, inclusive at Screening.
2. Passes the gait speed criteria at Screening.
3. Minimum body weight of 50 kgs at Screening.
4. Subject is willing and able to comply with all study procedures including randomization into any of the experimental groups, maintenance of habitual dietary intake, exercise and medication and supplement use, blood draws and the following prior to test visits: fasting (≥10 h; water only), no alcohol (≥ 10 h), no cannabis products (≥10 h) and no exercise (≥ 10 h).
5. Subject understands the study procedures and can provide informed consent to participate in the study.
Exclusion Criteria:
1. Subject is non ambulatory.
2. Subject has a CSHA clinical frailty score \> 5.
3. Subject requires assistance with any activity of daily living, excluding continence.
4. Subject lives in an institutional setting (skilled nursing facility or residential care facility for the elderly).
5. Subject is a female who has not passed menopause.
6. Subject is unable to converse in English (or Spanish, if available at the study site).
7. Subject has been hospitalized within 30 days of Screening.
8. Subject has any physical limitation that would prevent them from performing 1RM leg press based on Medical Officer judgement.
9. Subject has an abnormal laboratory test result(s) of clinical importance at Screening, indicating unstable chronic disease of major organ dysfunction that requires urgent evaluation, at the discretion of the Medical Officer. One re-test will be allowed on a separate day prior to Visit 1, for subjects with abnormal laboratory test results. Additional clinical information may be gathered from the participant if needed to interpret the urgency of laboratory abnormalities (e.g. recent laboratory trends if an electrolyte is abnormal).
10. Subject has uncontrolled hypercholesterolemia on screening labs.
11. Subject has a history or presence of acute or uncontrolled and/or clinically active pulmonary (chronic obstructive pulmonary disease \>= Gold 3), cardiac (e.g. \>= New York Heart Association class III), hepatic (cirrhosis), renal (chronic kidney disease stage \>= IIIb), endocrine (including type 1 diabetes), hematologic, immunologic, neurologic (e.g., Alzheimer's or Parkinson's diseases), psychiatric (including unstable depression and/or anxiety disorders) or biliary disorders. "Uncontrolled" and "clinically active" are per the judgement of the Medical Officer. Stable chronic disease is not an exclusion criterion unless specified. Chronic disease that is managed with the patient's physician per shared decision-making, even if sub optimally by typically recommended care, is not an exclusion criterion unless uncontrolled or clinically active.
12. Subject has a clinically important gastrointestinal condition that would potentially interfere with the evaluation of the study beverage \[e.g., inflammatory bowel disease, irritable bowel syndrome, chronic constipation, severe constipation (in the opinion of the Medical Officer), history of frequent diarrhea, history of surgery for weight loss, gastroparesis, systemic disease that might affect gut motility according to the Investigator, history of gastrointestinal ulcers or bleeding, history of pancreatitis, history of hiatal hernia, history of Barrett's esophagus, or history of esophageal cancer\].
13. Heavy drinking (For women, 8 or more drinks per week. For men, 15 or more drinks per week).
14. Subject has a history of alcohol or substance abuse.
15. Subject has been instructed not to consume alcohol for medical reasons.
16. Subject has a known, clinically important allergy, intolerance, or sensitivity to any of the ingredients in the study beverages, including soy and milk protein.
17. Subject has uncontrolled hypertension as defined by the blood pressure measured at Screening. For subjects with elevated blood pressure at Screening, they are allowed for the purpose of this criteria to submit home readings from three separate days, or to have a repeat reading taken at the study site on a separate day before Visit 1.
18. Subject is undergoing treatment or active surveillance for cancer or has been diagnosed with cancer in the prior two years, except for non-melanoma skin cancer. Active surveillance is defined as regular imaging or laboratory tests at a frequency greater than annually. Cancer under long-term monitoring such as stable chronic lymphocytic leukemia need not be an exclusion, on the discretion of the Medical Officer.
19. Immunosuppressive disorders, taking immunosuppressive medications (including oral prednisone \>10mg/day and biological immunosuppressants), or receiving chemotherapy.
20. Chronic antibiotic use (e.g. expected to be ongoing, regardless of frequency, throughout the study period).
21. Subject has extreme dietary habits (e.g., intermittent fasting or time restricted eating, Atkins diet, vegan, very high protein/low carbohydrate or has used weight-loss medications (including over-the-counter medications and/or supplements) or programs within 30 days of Screening.
22. Subject has followed a ketogenic diet or used ketone supplements (ketone salts or esters, and medium chain triglycerides) within 30 days of Screening.
23. Subject has a condition the Medical Officer believes would interfere with their ability to provide informed consent, comply with the study protocol, which might confound the interpretation of the study results, or put the subject at undue risk.
24. Subject works nights or shifts that means it is not possible to maintain a consistent meal schedule during the study.
