Is GPDH Responsible for That Beer Belly or Those Fat Hips?
What is GPDH?
GPDH -- also known as Glycerol 3-phosphate dehydrogenase or alpha-glycerol phosphate -- may be one of the most important and generally overlooked molecules in
What role does alpha-glycerol phosphate play in weight gain?
It stimulates the
creation of fat tissue.
How does it do this?
By changing the dynamics of what’s known as the fatty acid triglyceride cycle.
And why is that cycle important?
Because it is constantly going on in our fat tissue and is intimately bound up with how and why we fatten. Triglyceride molecules (TGs) are relative big and tend to get stuck in our fat tissue; whereas free fatty acids (FFAs) can escape (assuming they are not "re-esterified" into TGs), and once free they can be burned by the body as fuel.
In simpler terms, when we create more TGs than FFAs, we accumulate fat.
So how does alpha-glycerol phosphate change this cycle?
When fat is regulated normally, the TG-FFA cycle proceeds apace and we don't gain weight.
The presence of alpha-glycerol phosphate, on the other hand, changes the rate at which FFAs become bound up with glycerol molecules to form TGs, catalyzing the preferential formation of the larger TGs.
How do we get alpha-glycerol phosphate?
We make it as a byproduct of digestion. When we eat sugar, our insulin levels go up. Insulin, in turn, drives sugar into fat cells, where it is oxidized. Alpha-glycerol phosphate is a product of that oxidation.
Thus, a hypothetical mechanism for why people get fat might be as simple as the following:
- We eat carbohydrates.
- We produce more alpha-glycerol phosphate molecules.
- We preferentially bind up free fatty acids into triglycerides.
- We repeat this over time.
- Our fat tissue increases in size.
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