Dr. Ben Bikman

So...

Coming back to the fat cell, you have to have both.

You have to have elevated insulin sufficient to tell the fat cell to store that energy, but then you have to have the energy to store.

So calories matter, but so too does the insulin stimulus because in the absence of the insulin stimulus, there is no such thing as fat storage and indeed the body can't stop breaking down the fat.

And in fact, that's what ketones are.

Ketones are nothing more than a sign of the liver burning a lot of fat, where it's burning so much fat, it has such an abundance of acetyl-CoA that it can no longer feed the acetyl-CoA into the citrate cycle because it's too full.

It cannot divert it to lipogenesis because insulin is low, so that pathway is inhibited or not activated.

And then the only other option of all that acetyl-CoA is ketogenesis.

So ketones are simply sort of this overflow, this metabolic release valve of fat burning.

they go one step further, if you'll allow me, where how do we then reconcile it?

What is it about insulin?

I'm not saying calories don't matter.

I'm not trying to break the laws of thermodynamics.

In fact, my PhD is bioenergetics.

I have a unique appreciation for energy in organisms so that those carbons need to be accounted for.

But the more insulin is low,

You have two adaptations that allow the body to stay lean or to not store that excess that they're eating as fat, which is one, a higher metabolic rate by several hundred calories a day when insulin goes down.

So the body's just burning a little hotter.

The engine is revving higher.

So the overall energy expenditure is up again by 200 to 500 calories a day.