Protein showdown: which drink helps seniors most?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * English-literate and able to give informed consent * Adults 60 to 80 years old (inclusive) * (If applicable) Postmenopausal * BMI of 18·5 to 30 kg/m2 (inclusive) Exclusion Criteria: * Currently participating in another clinical study that involves altering the regular diet and/or involves consuming a dietary supplement or investigated food product as an intervention * Weight change \>3 kg in the past 3 months * Exercising vigorously over the past 3 months (i.e., engaging in high-intensity exercises for more than 3 hours a week, where high-intensity exercises leave one out of breath and unable to talk or sing during the workout) * Current smokers or have quit smoking for less than 5 years * Drinking \>2 alcoholic drinks per day (i.e., one drink is defined as either 150 ml of wine, 340 ml of beer/cider or 45 ml of distilled spirit) * If drinking ≤2 alcoholic drinks per day, not willing to stop consumption of alcoholic beverages two days before and on the day of the test visits (total 12 days) * Not willing to stop consumption of caffeinated beverages 10 to 12 hours before and on the day of the test visits (total 4 days) * Taking supplements containing omega-3, magnesium, gamma-aminobutyric acid (GABA), L-theanine, melatonin and/or 5-hydroxytryptophan for the past 3 months, and not willing to discontinue usage 3 months before and during the study duration * Currently on a specialised diet (e.g., vegetarian, vegan, weight loss diet) * Had serious food allergies in the past, or having intolerance, sensitivities or allergies to any of the following: milk/dairy products (e.g., casein, whey), starch/starch-derived products (e.g., rice, corn, wheat, potato), soy/soy-derived products, gluten, eggs, nuts, peanuts, fish and crustaceans. * Disease or impairment of the kidney and/or liver * Currently diagnosed with diabetes, sleep disorders, gastrointestinal issues (e.g., lactose intolerance, irritable bowel syndrome), gout and/or G6PD deficiency * History of diseases known to affect the central nervous system (e.g., heart disease, stroke, migraine headaches, multiple sclerosis, Parkinson's disease, mental illnesses) * Taking antibiotics 2 weeks prior to study participation * Taking medication known to interfere with cognitive function and mental wellbeing (e.g., benzodiazepines, antidepressants, other central nervous agents) * Taking anti-hypertensive or cholesterol-lowering drugs for less than 3 years unless medically declared by an official doctor to be in stable condition * Poor peripheral venous access based on past experiences with blood drawing