I recently heard from someone that fasting is “stupid” because of the muscle loss that happens while fasting. I was thinking, really? After only 24-36 hours? And if so, then how much? Is this going to harm me in the long run?

As I started reading up on this, I found several very interesting things. First of all, the short answer is yes. During a fast the body turns to muscle at some point to get needed glucose, which results in loss of muscle mass. The speed with which this happens depends on how much glucose your body is receiving. If you are on a “water only” fast, few things will happen at different times during the fast. After your body takes all the glucose it can from your last meal, it has to go elsewhere. It goes to your liver, which stores glucose in the form of glycogen. This is good for about 24 hours.

After that the body turns to fatty acids for its source of fuel. It breaks down the fatty acids in the reserves of stored fat in the body and around the organs. But the brain and our red blood cells need glucose to function. The body takes the glucose from glycerol in the fat tissues and the amino acids in muscle, thus beginning the process of muscle deterioration.

Reading this, I was thinking, this is no good. Our fasts are around 36 hours long. We start Sunday evening after dinner around 7pm and our next meal is Tuesday morning around 9am. During our fast we have as much water as we want and one or two cups of herbal tea. And usually Monday evening (after 24 hours into fasting) we have a cup of clear vegetable broth.

Before I get to the most interesting point, here is something very fascinating. It’s called Protein Sparing. During the fast, usually between 48 to 72 hours after the start, the body recognizes that taking glucose from the muscles is too inefficient and wasteful. The body then turns to ketosis, where the liver produces ketone bodies from fatty acids that the brain can use as fuel; only the red blood cells will continue using the muscles for fuel. This reduces the amount the muscles get used as fuel significantly and is referred to as “protein sparing.”

But our Monday fasts are not long enough for this to happen. And from what I have been able to ascertain so far, it does look like there may be some small muscle mass loss between 24-36 hours of the fast. So how concerned should I be?

And here is the point I find to be the most fascinating. The main reason we decided to start our weekly fast is based on the research that points to our bodies being able to get into a self healing state after the first 24 hours of fasting. (read our post Healing Of Our Bodies Can Begin With Fasting for info on this). Your body will consume the muscle mass, but it will start with the damaged tissue first! For example some scarred muscle tissue! The body is very smart. It will turn to the muscle if it has to, but it will start with the type of muscle that is deteriorated. It will only consume the healthy tissue after that. I can relax again, there is enough of damaged muscle tissue in me for my body to have a feast for a while during my fasts.

Let me end this article with the words from a nutritionist, naturopathic physician, educator and award-winning author Paavo Airola: “…your body will first decompose and burn those cells and tissues which are diseased, damaged, aging or dead. In fasting, your body feeds itself on the most impure and inferior materials, such as dead cells and morbid accumulations, tumors, abscesses, damaged tissues, fat deposits, etc. During fasting, while the old cells and diseased tissues are decomposed and burned, the building of new, healthy cells is stimulated and speeded up… Amino acids, the building blocks of proteins, are not wasted, but are released from the decomposed cells and used again in the new-building of young, vital cells.”

Research material: