Eli5 What is actually happening when you burn fat?

Question

This might be a stupid question, I might indeed be stupid. But what is the actual process going on inside my body at 290lbs when I go hiking for example?

In: 5

Answer 1

[Here’s](https://www.youtube.com/watch?v=NGKLpYtZ19Q) an interesting TED talk on the chemistry of weight loss.