What happens to when fat is lost?

[Ghost]

So you've just lost a pound (kilo, anything) of fat. You're super excited, finally, progress!

But where has that fat gone?

What happens to the calories, or the energy?

I've always wondered but just couldn't make sense of it.

Could someone please explain? I don't really know what I am talking about, but I can always learn.

Thanks.

[GoToTheGround]

Your body is burning that stored energy for fuel, expelled as heat loss etc.

Fat is stored inside the fat cell in the form of triaglycerol. The fat is not burned right there in the fat cell, it must be liberated from the fat cell through somewhat complex hormonal/enzymatic pathways. When stimulated to do so, the fat cell simply releases its contents (triaglycerol) into the bloodstream as free fatty acids (FFA's), and they are transported through the blood to the tissues where the energy is needed.

A fairly useful article: http://www.muscleandstrength.com/articles/what-happens-when-fat-is-burned.html