I have heard the term sugar burner and fat burner thrown around in the topic of metabolic inflexibility…
The idea is that some people are unable to start burning fat, and some seem to suggest that this happens as a result of adaptation regardless of energy content of diet. So, if not from the diet, where are the carbohydrates coming from in sugar burners if removed from the diet?
Since muscle glycogen cannot mobilized unless contracting/exercising, how could the body continue to burn mostly carbs for several days on low carb diet with energy deficit? Liver glycogen stores are pretty modest at 400kcals - which could easily be burned through a night’s sleep.
Most text I have read suggests that the absorptive period is about 3-5 hours - do larger meals digest substantially beyond this period? Can a large meal with substantial CHO in the evening take 8-10 hours to digest and absorb?
Let me know if I am missing something here! Thanks!
>The idea is that some people are unable to start burning fat,
These people would be dead. You only have 400 calories of glucose stored in the liver. Not enough to get through the night
Metabolic flexibility as purported by low carbers is nonsense
Everyone can enter fat burning Ketosis. Consistent high carb meals causing ones metabolism to rely upon the carb/insulin cycle is like muscle memory. When I began fast/ keto meal cycles, it took me almost 3 days to show Ketosis signifiers. After 4 months , I was dropping into ketosis in less than 15 hrs. I learned alot about it before attempting this and found a basic online primer in (Dr. Eric Berg).