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by m_kos 1590 days ago
> gluconeogenesis

I am very curious about gluconeogenesis. I am well aware of this pathway but have read a few times that glucose generation from protein happens very rarely. Have you ever tried eating zero carb whey protein in a fasted state? If yes, have you noticed a spike in glucose? I am genuinely very interested in your experience with gluconeogenesis as a person with diabetes.

1 comments

Oh, I am very happy to answer this to the extent I can. Whey protein impacts my blood glucose in confusing ways! Most days, I'll have a whey protein shake that consists of one scoop whey protein, a little bit of coffee for taste, and some almond milk. This will typically be my first meal after ~12-16 hours without eating. The correct dose of insulin for this shake can vary from 2 units of insulin to 4.

First, I believe you're correct that gluconeogenesis happens rarely. More specifically, I believe it happens in the absence of carbohydrates in the food you consume. Since I eat a low carb diet, it would make sense that I experience gluconeogenesis.

Second, have I noticed a spike in glucose? Yes! I have to take some amount of insulin if I have a protein shake. The coffee has no effect, so any effect comes from the almond milk and whey. There's maybe half a cup of almond milk in my shakes which is close to negligible. We can probably assume that whey drives most of the glucose effects from my shake.

Third, why is there so much variance in my blood glucose response and insulin requirements? Here, I do not have a defined answer. One aspect may be that whey is quickly digested. The quick digestion may accelerate the effect of gluconeogenesis. Another factor may be the state of the glucose reserves in my liver before I consume the whey. If I'm in a state of ketosis, it may be that my body accelerates gluconeogenesis because it believes it's in a carbohydrate shortage. In this situation, the glucose spike may exceed what would otherwise be expected. There's a few other things such as exercise I'd include here, but I don't have a single definitive answer to this.

A final note: In some sense, I can feel/anticipate my insulin sensitivity during the day. I cannot explain this in writing in any coherent way, but I have decent intuition on what insulin dose between 2 and 4 units I should pick each day. Or, before bed, even if my blood sugar appears constant and in-range, I may anticipate that it'll go up and down as I sleep and eat/inject insulin accordingly. One part of this intuition is "knowing" rather a protein heavy meal will kick into gluconeogenesis while I sleep. Anyways, I can answer more, but as you can perhaps tell, most of my explanations are of the waves hands variety.

Thank you for such a thorough and informative response!
> have to take some amount of insulin

There are quite a few pathways for your muscles and liver to release "stored glocose". If you want to artificially do it, get a glucagon siringe and get the worst hyperglycaemia you ever had since your liver starts converting glycogen into glucose en-masse. Natural release of glucagon is also regulated by having a low carb diet.

I just want to point out that gluconeogenesis can also use fatty acids to obtain glucose.