Fasting has been with us since time immemorial. Our Paleolithic ancestors went numerous days without food when either climate, pestilence, or disease interfered. Evolutionarily speaking, our bodies are quite adept at going several hours, if not days, without eating. The Bible details several occasions when fasting is done as a metaphorical and literal cleansing of the body and mind. More recently, several religions (Buddhism, Catholicism, Orthodoxy, Islam, and Mormonism) exhort this practice. This article will provide a elementary understanding of intermittent fasting and its benefit to the body.
Why should you fast?
The better question is “Why shouldn’t you fast?” Seriously, here is a quick list, by no means exhaustive, how fasting helps you optimize your health.
Fasting promotes caloric efficiency meaning the body learns to “do more with less.” As such, the body learns to need less calories to perform the same tasks as before. This leads to a more efficient, optimized body.
The body and its organs and muscles use glucose (typically consumed as carbohydrates) as its primary fuel. When we eat, the body metabolizes the food and the pancreas releases insulin to allow the excess glucose in our blood to be stored in our organs and muscles. The remaining glucose is sent to the liver to be stored as glycogen. Afterwards, any excess glucose is turned into fat. If one is eating every 4-6 hours this cycle is repeated and thus is is difficult to ever tap into your adipose fat to catabolize it to melt off the fat.
When the body is fasting, it will initially consume all of the glucose stored in the organs and muscles. It will then turn to the liver to deplete the glycogen. When that is exhausted, the body does a crazy thing: it will turn to your stored adipose fat!
The body converts the fat into ketones which is then used as fuel by the organs. As a result, one’s fat is burnt off, thus the resulting loss of body fat. Now this is a much-simplified version of ketosis, but please understand the basic principle. The body needs a very small amount of carbohydrates (glucose) to maintain itself (<50 grams carbs/day) and one does not need 4-6 meals a day, or even eat daily. This is a salient point which must not be understated and sadly is so sadly undermentioned in not only mainstream media, but even most personal trainers. They are still quagmired in the “calorie in, calorie out” model of the last 40 years.
In short, if done properly, intermittent fasting will burn your fat quickly.
To be succinct, the brain loves to run on ketones. Many people are familiar with the term “brain fog,” a term used to denote lack of concentration, decreased cognition, and increased forgetfulness. “Brain fog” is synonymous with a high carbohydrate diet. Conversely, the brain revs on high-octane on a ketogenic (ketone-fueled) diet.
Ketogenic diets may be accomplished either through fasting or a high-fat diet. This is partly due to brain-derived neurotrophic factor (BDNF.) BDNF activates brain stem cells to convert into new neurons, and triggers numerous other chemicals that promote neural health. Fasting turns you into Bradley Cooper’s character in the movie, Limitless, or Scarlett Johansson from the movie Lucy. The improved mental clarity you will manifest when on the final hours of a fast will astound you!
It’s all about blood flow and hormones. When you eat a large meal the body shunts blood to the intestines to metabolize your food. Every try working out an hour or two after eating? Sub-optimal workout at best. Now juxtapose that with exercising on an empty stomach, such as in the morning. At dawn, you have likely been fasting for 10-12 hours due to sleep. As such, when you work out all the body may shunt all the blood directly to your skeletal muscles thus optimizing your workout.
The same may be said for hormones. No insulin is present since you have not eaten in a while thus you will avoid the “sugar crash.” Working out while fasting allows for the release of adaptive hormones, such as growth hormone, testosterone, cortisol and adrenaline, all of which are beneficial to the body (the last two in short amounts). What about hypoglycemia? We will cover that later.
Reduced Inflammation and Aging
Why is sleep good for you? Because it allows the body to recover from a strenuous day and re calibrate the hormones. Fasting is essentially the same. Believe it or not, eating and metabolizing of foods takes a toll on the body, in particular your endocrine (hormone) and digestive systems. When you fast your endocrine system re-calibrates itself and the digestive organs may rest. (This too is why juice cleanses are so popular.)
In the fasting state cells flourish, for they are allowed to undergo the process of autophagy. Autophagy is when cells eliminate damaged cellular matter; thereby protecting the body against oxidative stress and inflammationn. When calories are abundant cells multiply freely thus increasing aging and possible cancer. Conversely, when deprived of calories cells must become more efficient in cellular respiration and autophagic (hearkening back to caloric efficiency).
Hormones responsible for growth, repair, and immune function are optimized since insulin levels are low. Fasting mitigates cell division thus slowing down aging. (Think of all those old Buddhist monks.) This is done by extending the length of telomeres, which are essentially the casing which keep our chromosomes in place. (OK, no more biochem.)
You have probably heard those “Low T” commercials ad nauseum. Aging naturally decreases free testosterone in the body, but that doesn’t necessarily mean that everyone over 40 should bemoan flabbiness, low libido, malaise, and decreased muscle mass. Fasting, along with high-intensity-interval training (HIIT) (exemplified by sprinting and lifting very heavy things in a short amount of time and on rare occasion) are methods to not only mitigate the effects of decreasing testosterone but possibly reverse it.
Other reasons exists as to the benefits of intermittent fasting (increased control of hunger, reduced insulin resistance, increased metabolism, etc). In the next article I will discuss the various methods in which fasting may be accomplished in a safe manner and pitfalls to avoid.
“Reach out to me…let me help you achieve your goals.”
A. Gregory Luna
Double-certified Health Consultant
(I would appreciate your comments below.)