Disclaimer: The cardinal rule to fasting is to do it safely, and avoid doing prolonged fasting without medical supervision.
As I mentioned in the last article, Intermittent fasting does help in reducing weight but the most important benefit of intermittent fasting is that it is the most effective way to trigger autophagy.
Now next question that comes is, what happens in autophagy?
To understand this first know that there are many things that happen when we fast that doesn’t happen when we are in a well-fed state or when our body is sourcing its energy from glucose
When our body is well-fed, every cell in your body is in a state of growth. In more technical terms, when our body has plentiful food in the body with carbs, nutrients, and proteins, insulin gets released and mTOR gets activated. When active these two tell the cell to grow, divide, and synthesize protein. They also tell the cell not to bother about the process of autophagy which is a process by which the body recycles and cleans up the damaged and misfolded proteins. These pathways if overactive, have implications in cancer growth too.
But things are different when your body is starving. When you are fasting, your body considers it a state of stress and works on handling this stress. So when you fast and exercise there is different kinds of pathways gets activated when glucose is not present, these are called AMPK pathways. AMPK pathways inhibit the mTOR pathways and tells the cell to be in a self-protective mode, which activates autophagy and fat breakdown.
This all when your body doesn’t receive any calories. But these processes at different times of fasting, and hence it’s very important to know what happens to your body so that you can be aware and experience that when you are actually fasting.
4-8 hours: Blood sugars fall, all food has left the stomach, insulin is no longer produced.
12 hours: Food consumed is burned, the digestive system goes to sleep, the body starts to break down and burn fat, some of this fat is used by the liver to convert it into ketones. The brain which usually runs on glucose partly starts using these ketones as an alternative source of energy, this is the moment when you have raised the level of mental clarity which is often talked about in fasting.
18 hours: Your body is switched to the fat-burning mode and generates a lot of ketones, somewhere around the value of 0.6 to 1.0. These levels of ketones signals your body to activate stress pathways(AMPK pathways) which starts reducing inflammation and starts repairing DNA.
24 hours: By this time your body is in a full-fledged recycling process called autophagy. It breaks down damaged proteins liked to Alzheimer’s and other diseases, removes damaged cellular components, and runs AMPK pathways.
48 hours: By this time the growth hormone level in the body reaches up to 5 times from the start of your fast. As we age, the growth hormones help preserve lean muscle mass and reduce all the accumulated fat tissues, hence they play a very important role in body healing, cardiovascular health, and longevity.
54 hours: By this time, the insulin levels in the body are at the there lowest level and your body starts to get increasingly insulin-sensitive. In the long run, making your body more insulin sensitive reduces your chances of having diabetes dramatically.
72 hours: By this time, your body starts breaking down old immune cells and generate new ones. This state of prolonged fasting leads to stress resistance, self-renewal, and regeneration of hematopoietic or blood cell stem cells. For patients who undergo chemotherapy, this prolonged fasting has shown to preserve healthy WBC or lymphocyte counts.
What you eat to break your fast is as critical as fasting to reap the maximum benefits of fasting, this is called the refeeding state. It’s advised not to eat a lot of carbs in breaking your fast, avoid any processed/packaged food. It’s best to break your fast with a light meal including vegetables, plant fibers, and plant fats, with healthy proteins and some whole grains or legumes if you choose.
