There's been studies to this, for example [1]

"Dando's previous research had already found that when you chemically block people's ability to taste sweet flavors, it makes them crave more sugar and seek out higher-calorie treats. Based on his collective research, we now know that drinking a caffeinated cup of coffee, which has the same blocking effect, makes people want cookies or cake more than they otherwise would."

Caffeine seems to blocks the adenosine receptors, which makes us feel less sleepy, but these same receptors also play a part in helping us taste sweet flavors. While doing this, it pushes us to find more sweet, sugary tastes. This might be a part of why when drinking coffee especially, which is also pungent and bitter in taste, opposed to sweet, might drive us toward these sugary treats.

Also I feel coffee depletes our energy levels very fast, making us feel more tired when the effect comes down, making hte body want to replenish those energies quickly, and high in sugar ingredients do that fast, with a price though.

It's interesting why tea and mate for example don't have this effect so clearly, maybe it has to do with the bitternes of coffee and the way it is roasted, not sure.

1: http://www.chicagotribune.com/lifestyles/health/ct-coffee-an...

A strong coffee (e.g. via a Moka pot) should send you to the bathroom too.

Would you have any sources on that?

I casually looked into that claim in the past and read that coffee is as strong a diuretic as pure water.

there's.... i believe there is enough anecdotal evidence to state with a reasonable confidence level that coffee makes you poop.

Yeah really no need to study this. There's "anecdotal" and then there's "this happens to 80% of people and we have cute euphemisms for when you excuse yourself" and that to me is as good as the most rigorous of studies. Now uhh, excuse me, back in a sec.

Chiming in for n+1. Can confirm: I enjoy my post-caffeine quiet time. :)

Hmmm, I smell an IG Nobel prize opportunity for an ambitious grad student who is not afraid to get his hands dirty.

What? I drink rather a lot of coffee and have never had that effect. I've never heard it from anyone else either. Is there any non-anecdotal evidence for this?

Do you primarily drink iced, cold brewed, or something like keurig?

Nope, just normal coffee. Sometimes made in a cafetiere, sometimes from the (rather good) machine at work, but I mostly make Greek or Turkish style these days. It's never given me a dose of the shits however its made though!

The caffeine relaxes the intestinal tract..

Caffeine is a stimulant. One of the things it stimulates are your colonic muscles which can induce peristalsis.

Perhaps they mean as a laxative rather than as a diuretic.

Yes, I believe so from the comments.