Hydration Science Hydration Guides
Browse all 4 hydration guides for hydration science.
Does Milk Hydrate Better Than Water?
In a landmark randomized trial, skim milk and whole milk both retained significantly more fluid than plain water — because protein, lactose, fat and sodium slow how fast the drink leaves your stomach.
Does Orange Juice Hydrate You?
In the landmark Beverage Hydration Index study, orange juice held fluid better than water two hours in - but the advantage disappeared by four hours, and OJ carries about 470 kcal per litre of energy you have to account for.
Does Sparkling Water Hydrate as Well as Still Water?
Carbonation changes the fizz, not the hydration. In a controlled 72-person trial, sparkling water held its own against plain water, retaining fluid just as effectively over four hours.
The Beverage Hydration Index: What Hydrates Better Than Water
A landmark randomized trial measured how 13 drinks are retained versus still water. Milk, ORS and orange juice topped water; coffee, tea, cola and beer matched it. None scored below water.