Black coffee - how many calories?

I don't know if you people can read, but I know that coffee has 2-5 calories, and I know that there is no such thing as negative calories which is why I used quotation marks around "negative calories"

What I clearly said was that coffee makes your body metabolism work harder whether needed or not, your fight or flight mode becomes more prominent and your "rest and digest" mode shuts down. Hence when you drink coffee your body uses more energy than it normally would, making you burn more calories than you have consumed. Same goes goes for drinking water. Similar, is eating celery, it has some calories, but your body burns more processing it than you have actually gained.
Hence the unorthodox term "negative calories," professor lemonsnowdrop.

As per hydration, anything you drink other than water will dehydrate you and you will urinate it out. When you drink alcohol, the higher concentration of alcohol( or caffeine or salt or any electrolyte) outside your cells will cause the water to leave the cells thus dehydrating you. That's why you urinate a lot when you drink alcohol or coffee and feel very thirsty when you eat a lot of salty fish or whatever.

I'm premed so don't argue with me.