Originally Posted by noogz256
so why does your liver turn protein into glucose when the body doesn't have any glucose? and when protein is burned, ketone bodies are produced which again...get turned into glucose. sugar...true you do not need to consume sugar but carbs...hell ya you need them.
By the time the body runs out of glucose, it goes into ketosis, producing ketone bodies in place of glucose. To have that to happen, fat is being burned to the point that it cannot keep up with maintaining the body's blood sugar, and that can be at least 36h of fat burning from not eating anything (fasting), or eating no-carb meals under a caloric deficit. It's not practical to do for some people due to the steep requirement of going into ketosis, and no way needed for fat loss.
Carbs weren't as abundant or as energy dense as it was during prenatal times, where the main source of carbs were fruits and vegetables. If it wasn't for the advent of processed food we wouldn't have so many cases of high blood sugar due to the overabundance of carb consumption without an outlet of energy removal.
We don't necessarily need them still, it just explains what the body does when glucose doesn't come available in what they eat if there are times of famine.