An Expert Explains If Coffee Causes Dehydration

To learn if coffee can dehydrate you, Chowhound spoke with food scientist Kantha Shelke. She says that to understand the effects of coffee, we have to know about its caffeine.

"Coffee contains caffeine, which acts as a mild diuretic and increases urine production," Shelke said. If you don't replace the liquids you lose to caffeine, you’ll get dehydrated.

While drinking one cup likely won't cause issues, Shelke said, "Consuming several cups of strong (and high-caffeine) coffee in a short period

may cause noticeable dehydration."

In addition, Shelke says, "Coffee on an empty stomach may act faster." To slow down coffee's effect,

stay hydrated by drinking other beverages and eating while you sip.

The last point that comes into play

is individual tolerance. "If one is unaccustomed to caffeine, consuming a high amount at once may

increase urine output," Shelke says.