How do negative calories work?

Question

I’ve heard about this thing so many times. How is it possible to eat something, but still burn calories?

In: Biology

Answer 1

It isn’t really a thing. At best, a food will have 0 cal. However, some foods require a lot of effort to eat AND have very few calories, and so your net calorie intake is negative. For example, if a baby carrot has around 4 calories, and you burn through 8 calories chewing it, you net -4 calories. At least, that’s the idea. I’m unconvinced.