How many calories are in a cup of coffee? The quick answers is that black coffee contains about 5 calories or about negative 100, depending on how you consider the science.  Roast Magazine published and interesting article on this topic of how many calories does a cup of black coffee contain.

You may be familiar with the counterintuitive idea of negative calories for foods such as celery, grapefruit or lettuce. Yet none of these popular fruits or vegetables actually have negative calories, so how can coffee, you ask?

To get to the bottom of this, we must first understand the nature of calories.

What is a calorie?

A calorie is a unit of measurement more similar to a British thermal unit (Btu) than to anything pertaining to biology. In fact, a calorie is the metric equivalent of a Btu. Where a Btu is the amount of energy required to raise 1 pound of water 1 degree fahrenheit, a calorie is the amount of energy required to raise 1 kilogram of water by 1 degree celsius.

Continue reading this article at Roast Magazine.