7 Surprising Things That Happen to Your Body When You Fast





In my last post, I described my personal experience with the Master Cleanse, or so-called “lemonade cleanse,” which is basically a 10-day (or more) water fast.

Now, that was just my anecdotal evidence on the risks and benefits of fasting, but what does the scientific literature (if any) say about the effects of fasting on your body? Are the critics correct in their assertion that such cleanses are dangerous at worst, and completely unnecessary at best?

Read on for a list of 7 physiological and biological changes that happen within your body when you do a fast.

7 Things That Will Happen to Your Body When You Fast

1.Weight Loss

Ok, so this first one is probably not so surprising, it’s pretty obvious: restrict calories and the body must draw energy from sources other than food, starting with adipose tissue (aka our lovely lady lumps).

After just 3 days of fasting, the body begins a process known as ketogenesis, whereby ketones are produced in the liver, resulting in the body beginning to break down fatty acids to supply itself with energy. [1]

In addition, (and maybe more surprising) fasting increases growth hormone, which also facilitates fat burning and muscle gains. This is often the foremost reason people decide to take on something as challenging as a 10-day water fast <raises hand>, or simply tries intermittent fasting.

2. Slow Down the Aging Process

Increased ketone bodies due to ketogenesis also helps cells resist oxidative stress [1]. Oxidation plays a corrosive role within the body which results in the bodies reduced ability to neutralize toxic substances. As it becomes more overwhelmed, free radicals increase. Free radicals then have the potential to damage your cells resulting in, among other things, premature aging (that ugly, ugly word). Fasting reduces oxidative stress, optimizes energy metabolism, and supports stress resistance by increasing parasympathetic tone. [2]

In other words? Fewer wrinkles for you, dear reader. I can drink (water) to that!

3. Fight Cancer

According to a study by the Department of Radiation Oncology at the Robert Lurie Cancer Center, fasting may protect cells against carcinogens [3], a substance or agent that can cause cancer. Fasting can increase certain proteins such as SIRT3 which are involved in aspects of longevity [2], stress response and metabolism resulting in a reduction of cancerous cells.

4.  Boost the Immune System

Fasting enhances immunological defenses, decreasing inflammation throughout the body by triggering the synthesis of glucocorticoids (the natural equivalent of steroids) and inhibiting the degranulation of mast cells, a process that plays a role in allergic disorders by causing cells to burst and release histamine which in turn triggers inflammation. [1]

5. Improve Circadian Rhythm and Sleep

Fasting affects circadian rhythm by producing cardio-metabolic improvements and synchronizing the body. By contrast, eating meals at irregular times (like late at night) can disrupt sleep. In turn, proper, restorative sleep can in and of itself aid the detoxification process at the cellular level by helping to clear neurotoxic waste from the central nervous system. [2]

6. Protect Against and Reduce Symptoms of Autoimmune Disorders

One way fasting reduces autoimmunity is by affecting intestinal permeability, a condition that leads to disorders like leaky gut, and is a precursor to autoimmune diseases. (Leaky gut can lead to other issues like hypothyroidism.) By giving the digestive system a break from potentially allergenic foods, the lining of the intestine is able to repair and heal. In addition, fasting reduces the “antigenic load,” or the energy the body must expend in processes such as digestion. As a result, the body can better turn its attention to other regenerative actions. [2]

7. Protect the Brain

According to a 2013 study by the Department of Anesthesiology, of the University of Virginia, mice who were put on an intermittent (alternative-day) fast, showed greater gains in learning and memory compared to mice who were not. [4]

By increasing production of proteins that suppress oxidation and free radicals, fasting can increase the resistance of brain cells to malfunction and die by protecting neurons and increasing the number of new neural cells in the adult brain. [5]

I don’t know about you, but these sound like some pretty amazing “side-effects” of a (properly executed) fast. No wonder I recall feeling so energetic and clear-headed by the end of my fast!

The best part about it is that you don’t have to commit to a grueling 10, 20 or 30-day fast to get these benefits (which may not be healthy anyway). Even alternate day fasting, eating your breakfast later in morning (say at 9 or 10 am), or your dinner earlier in the evening (around 4 or 5 pm), can put your body into a mini-fasting mode.

As for the critics? It may be true that you will be limiting nutrients, and to do so for prolonged periods of time may be dangerous [6], but intermittent fasting has been shown to be relatively safe and effective.

If you’re looking for a way to seriously benefit almost every system of your body, or just kick-start a cleanse or new healthy eating habits, fasting may be the just the thing you need!

Have you ever done a fast? Let me know in the comments!

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