Glycerol Follow Up

My post on glycerol still had me thinking and I couldn't seem to find an answer by researching. So I decided to ask my nutrition professor here at the University of Florida Dr. Harry Sitren, PhD.

I inquired "Why doesn't the body just deanimate triglycerides and use the glycerol backbone to synthesize glucose while on a no/low carb diet?"

His response in a nutshell:

It can and it does.

The problem is, glucose is a 6 carbon sugar. Glycerol is a 3 carbon sugar. So for every one triglyceride molecule, we can make one half glucose.

Moreover, triglycerides are only broken down to monoglycerides in the intestinal tract. So it needs to be further deanimated before synthesis of glucose from glycerol can occur.

Basically, not only is it an inefficient process but it's also a metabolically expensive process- maybe even more expensive than the energy it would yield.

This explains why the body opts for ketosis instead.

Theoretically, consuming glycerol could not a person out of ketosis because of the aforementioned processes even though it doesn't raise blood sugar. However, one would have to consume a VERY large amount of it.