I worded that poorly, sorry. "and therefore save glucose" would have better read, "the body does not need glucose for energy".

This question is doing more for me than you know. I hope I can explain everything right now since it is all a just a picture in my head. So if this does not make sense I can go on.

I want to take a step waaaay back. Most people think it is ketones, glucose, protein, or fats that the body wants for energy. Well, they are all wrong. The body wants Actyl-CoA for energy. Acetyl-CoA drives the TCA cycle and that is what keeps us alive. All of those things are sources of Acetyl-CoA.

https://www.researchgate.net/figure/Origin-and-fate-of-acety...

Next, the body does not prefer ketones as a source of Acetyl-CoA, in MOST PEOPLES (depending on genetics) it prefers glucose above all else.

https://www.ncbi.nlm.nih.gov/books/NBK493179/
"Most organs and tissues can use ketone bodies as an alternative source of energy. The brain uses them as a major source of energy during periods where glucose is not readily available. This is because, unlike other organs in the body, the brain has an absolute minimum glucose requirement."

So being in ketosis is a rescue situation when there is not enough Acetyl CoA being made from glucose. You want proof of this? Fasting increases ketones levels more than any diet.

https://www.medicalnewstoday.com/articles/324599#_noHeaderPr...

If a person genetically prefers glucose over fats for making Acetyl CoA, my guess is that they will go into ketosis much more slowly.

So once the body runs out of it's preferred source of energy, glucose, it resorts to its second best source; fat. Now how are fats used for energy?

https://els-jbs-prod-cdn.jbs.elsevierhealth.com/cms/asset/e1...

They are turned into Acetyl CoA BEFORE it enters the cell and needs CPT1A to enter the cell. Both glucose and protein enter the cell and THEN are turned into Acetyl CoA.

But all this is NOT TRUE of the Inuit. Their preferred source is from fat, not glucose. Why? Because of the genetic changes resulting from a diet high in fat. So for the Inuit, a high glucose diet causes problems like a high fat diet does for most European caucasians.

Let's look at the problem for people with CPT1A deficiency. They enter a state of "hypoketotic hypoglycaemia". Low glucose AND low ketones. So we know that we need CPT1A to function to make ketones to power the TCA cycle.

I am still trying to reason why CPT1A transport slows down so much for the Inuit. But I know it is because of generational dependance on a high fat diet. It seems that Omega 3 might change the expression of CPT1A making it more effective. Omega 9 fats increase CPT1A activity.

https://www.nature.com/articles/s41431-020-0674-0

This is probably the best Paper on this confusing topic.

https://escholarship.org/content/qt8wz5h9kp/qt8wz5h9kp.pdf?t...

"Given that the PUFA content of traditional Arctic diets may compensate for the genetic reduction of CPT1A activity, and that the absence of urinary ketones found in early studies in North America may reflect fat adaptation and limitations in testing technology, current speculation about the lack of a ketogenic state in traditionally living Arctic peoples cannot be considered settled."

I mean, if you think about it, having high ketones means your body is not USING the ketones for energy. Wow, that just blew my mind! Time to look at my ketone genetics!

Thank you!