Water is being unseated as the king of hydration . . . by milk?
Researchers at St. Andrews University in Scotland compared the hydration responses to a variety of drinks, and found that beverages with a little bit of sugar, fat or protein keep you hydrated longer than water. They found milk in particular is more hydrating because it contains lactose, protein and some fat, all of which help to keep hydration happening over a longer period of time.
In case you didn’t know how hydration works - the more you drink, the faster the drink empties from your stomach and gets absorbed into the bloodstream, where it can dilute the body's fluids and hydrate you.
No, your latte won’t count as a good hydrater. Caffeine causes the body to flush fluids more.