The Science Behind Coffee, Caffeine, & Dehydration

Ever drink a ton of coffee and have to pee really bad right after? Yup, me too!

But the science says that coffee dehydrates you, and often times when you drink coffee your urine tends to be more on the dark yellow side. What gives?

Here’s what the research says…

1. Caffeine has a slight diuretic effect, meaning it will make you want to urinate more, which could dehydrate you.

2. When caffeine is consumed with fluids (coffee, tea, energy drinks, etc.), the fluid ingested will hydrate you more than the caffeine dehydrates you.

Although the science behind the statement “caffeine dehydrates you” is true, the statement “coffee dehydrates you” is false. This is because the fluid in coffee will counteract the dehydrating effect of the caffeine.

Why then, is urine often times dark yellow when drinking coffee? Think about it…when you drink coffee, are you chugging it, or sipping it slowly? Okay maybe occasionally you are chugging, but for the most part it is a slow sip.

When you sip slowly, what are you doing? Limiting your overall fluid intake. The behavioral aspect of drinking coffee slowly is what tends to dehydrate people, and is likely why your urine is darker when drinking coffee.

Solution? Make sure to sip water in between sips of coffee in order to prevent getting overly dehydrated.

I discuss this in more detail in the video below.