Does Drinking Coffee Dehydrate You

People have long been warned that drinking too much coffee will cause dehydration. But research suggests there s little truth to that claim: one 2014 study found that caffeine had no effect on the hydration status of 50 subjects, who first drank coffee as their primary drink, and drank water in the experiment s second phase. Another study found that coffee did not dehydrate tired athletes who drank it during practice. Though caffeine does have a diuretic effect, it isn t strong enough to cause the body to excrete more liquid than it s taking in. What s more, habitual coffee drinkers will find that this diuretic effect diminishes as their system becomes accustomed to the caffeine.