The Biochemistry Of Starvation Metabolism

Let's talk plain language about starvation metabolism. The biochemistry and physiology behind this is not well understood. Why? Because you would have to do starvation experiments, and no doctor or researcher is allowed to do that.

Not on humans, not on monkeys, not even on rats. That's why diet advisors like to argue about the fastest way to lose weight without going into starvation. There is simply no scientific data on it.

This Is What Happens In The Radically Starved Body 

Let's say you're on a zero diet: just water, tea, and vitamin pills, no calories. Your blood sugar level begins to drop and the pancreas stops producing insulin. Your muscles meet their resting needs from fatty acids. Your liver still has to keep blood sugar levels above 40 mg/dl because your brain and red blood cells depend on glucose.

To do this, the liver converts various substances into sugar: pyruvate and lactate from muscle metabolism, glycerol from fat and proteins. Unfortunately, only small amounts of the first three raw materials are in the blood. Less than 24 hours after your last meal, your liver has to resort to protein. On the first and second day of a zero diet, the body burns a total of about 150 grams of muscle mass to supply the brain.

From The Third Day Of Fasting

The second priority of starvation metabolism is to keep the muscles as long as possible because you need them to survive. The liver meets its own requirements from fat. It also converts fatty acids into ketone bodies. From the third day of a radical fast, the brain begins to get some of its energy needs from these ketone bodies.

 If starvation lasts for weeks, the brain metabolizes large amounts of ketone bodies. His sugar consumption drops from 120 grams per day to about 40 grams. The liver now burns about 20 grams of muscle mass per day, the rest of the energy comes from the fat deposits. Only when there is no more fat left does the metabolism switch completely to burning protein.