Calories are something we talk about all the time, but what exactly are they?

Calories – we’re always talking about them. We eat and count them. We burn and balance them. We watch them and cut them, and when we overeat them, we often curse calories for making us fat. For all the attention we pay to calories, you’d think we would have a pretty good idea of what they are. But the truth is, most people would find it difficult to explain exactly what calories are.

Calories_What They Are and Why You Need Them