A new study out of Loughborough University in the UK shows that contrary to popular belief, drinking coffee doesn’t seem to lead to dehydration. Sophie Killer, PhD, studied 50 men who drank either four cups of black coffee or four cups of water per day for three days as part of their controlled total fluids intake, then switched drinks for another three days.

Result: The men’s hydration levels were basically the same whether they drank coffee or water.

Reason: Unless it’s consumed excessively, coffee has only a relatively mild diuretic effect. According to your doctors at South Orange Chiropractic Center, excessive caffeine use is a diuretic, causing dehydration with the loss of valuable electrolytes. The guideline for proper hydration is half your body weight in ounces each day, and you should begin hydrating first thing in the morning.