In this study, the investigators want to assess the effects of a new beverage containing whey protein and glycerol (two different dosages) on hydration status in healthy adults when compared to the control (water).

This is a single-center, double-blinded, 3 arm cross-over randomized controlled study looking to enroll 45 healthy adult participants. The study will be performed at the Clinical Innovation Lab (CIL), Nestlé Research, Lausanne. Participants will be screened and randomly assigned to 1 of 6 sequences of consumption. Enrolled participants will have three visit days. They will consume one of the test products, or control at each visit and complete the study assessments.

Inclusion Criteria:

1. Female and male adults aged 18-50 years.
2. Body mass index (BMI) between 18.5 to 25 kg/m² (inclusive).
3. Healthy as determined based on self-reported medical history.
4. Able to understand and to sign a written informed consent prior to study enrolment.
5. Willing and able to comply with the requirements for participation in this study.

Exclusion Criteria:

1. Any past or on-going diagnosed medical/surgical condition (e.g. malignancy, renal condition, liver condition, uncontrolled diabetes mellitus, cardiovascular disease, hypertension, migraine and headache disorders) and/ or psychiatric condition (e.g. depression, psychotic disorders, chronic insomnia, eating disorder), which in the opinion of the site physician/investigator may risk participant's well-being/safety, impede participant compliance with study procedures or ability to complete the study and/or could confound the primary objectives of the study.
2. Current intake of medication/s that impact hydration status (e.g. anti-hypertensive medications, anti-diabetic medications, anti-psychotics, anti-depressants, diuretics, laxatives, antidiuretic hormone (ADH) antagonists, oral corticosteroids, glucocorticoids, anti-cholinergic medications, or cyclosporine A).
3. Currently on a high-protein (1.5g/kg/BW/day) or ketogenic diet (based on self-report).
4. Known/suspected food allergy or intolerance to any food (based on self-report).
5. Female participants who are pregnant, lactating and/or breastfeeding (self-report or if in doubt, via urine pregnancy test).
6. Any self-reported chronic alcohol or drug abuse within the past year; specifically, an average alcohol intake > 2 standard drinks per day over a week for males, and > 1 standard drink per day over a week for females. One standard drink contains 10-12 g of ethanol, i.e., 0.3 dl of strong alcohols, 1dl of wine, 3 dl of beer.
7. Currently participating in another interventional study.
8. Family or hierarchical relationships with the research team members.