What Happens to your Body During a Water Fast

Whether you’re currently fasting or heavily considering a fast, this info will be a source of inspo- to push you along your journey. Find out what happens to your body during a water fast.*

Let’s face it, when you’re in the thick of a fast, it’s nice to go back the to science of things to drive you forward if things get tough (as they may). Going back to the science of fasting can also serve as a reminder as to why the heck you’re fasting in the first place!

Here is a breakdown on what happens to your body during a fast–from the moment you begin your fast, up to 4 days:

Before we dive in, it’s best you understand how intelligent your body is and how it is ALWAYS working to heal you…

This healing process is interrupted when we eat. Our body’s intelligence has to shift it’s priorities to digesting food. What does this mean? Let’s put this into perspective: when we are constantly eating throughout the day, our body’s internal intelligence system will always be looking to tackle immediate situations like digestion. So, if the only time we aren’t eating is when we are sleeping, our bodies only have about 6-10 hours to work on healing itself. Depending on the time you stopped eating before bed, most of what will be happening during your sleep time would be digestion.

Now, let’s take food OUT of the Equation

Take food out the equation and therein lies a whole world of chemical reactions that will occur in your body. Cease from eating, sit back and just watch what your body does.

Here’s what happens when you begin eating the last meal before your fast:

Your body will receive an insulin spike. The size of insulin spike depends on the amount of protein or carb you’re having in that meal. If it’s high-protein, high-carb you’re going to get a really big insulin spike. It will take about 8-10 hours for that insulin and glucose to start to come down. If you’re eating a lower sugar, carb, or protein meal, your insulin spike will no be as high and will begin to come down a lot quicker.

Cheat code: If the last meal before your fast was a low carb/protein/sugar meal, you will encounter all of the benefits of fasting much quicker!

The Moment you Stop Eating…

It typically takes about 8-12 hours after your last meal to fully enter a fasted state.  

12-13 hours of Fasting:

Growth hormone (GH) kicks in. In fact, research shows that you get a boost of about 1300% just from 12-13 hours of fasting.

Growth hormone is really important because it helps us burn fat, build muscle, and slows down the aging process. It’s also important to note that it begins to decline because once we hit the age of 30.

13-15 hours of Fasting

The body starts to sense that no more food is coming. It will begin to transition from burning the energy from sugar, to burning fat for fuel. If you’re looking to lose weight with fasting, this is the switch/transition that you’re trying to make happen.

The way that your body lets you know that this switch has happened is by an increase in ketones. Ketones are healing. The more ketones your body has, the more healing is taking place in the brain, and in the cells of your body.

17 hours of Fasting

By this time, you are well into the fasting “sweet spot”. Autophagy begins to kick in. Autophagy is when the cells of your body notices that your blood sugar is going down and there is no food coming in, so they (the cells) find food elsewhere. Where is elsewhere? Within the cell itself. This is called cellular detoxification. It can continue long and strong up until the 72 hour mark of a fasting (according to research). After the 72 hour mark, autophagy does continue, just at a slower, steady pace.

Here’s a summary of what’s going in the body thus far. Growth hormone is switched on. Autophagy is turned on. Plus, the body is learning to become “Fat-Adapted” and will start to make more and more ketones!

[“Fat adapation: a long-term metabolic adjustment to ketosis, a state in which your body burns fat for fuel instead of carbs. Fat adaptation is said to result in decreased cravings, increased energy levels, and improved sleep.”]

At 24 hours of Fasting

There’s so much magic that gets turned on at this point. At the 24 hour mark of fasting, 3 major organs begin to repair and go into an accelerated healing state:

The Gut (Small and Large Intestine): An MIT study states that your intestinal stem cells begin to regenerate after being in a fasted state. This helps with leaky gut, candida, SIBO, or any other digestive issues that you might have. If you keep fasting past 24 hours, those intestinal stem cells will continue to heal and repair.

The Brain: At 24 hours, your body starts to create more BDNF (Brain-Derived Neurotrophic Factor) for the brain. BDNF is a like protein fertilizer for the brain. It goes into the brain and REPAIRS degenerating neurons that cause memory loss, brain fog, the inability to focus, depression, anxiety, and trouble with learning.

The cool thing about BDNF is that when it goes up, serotonin levels go up, too! A surge in serotonin is great especially when fasting because it makes you happy!

Inflammation: Also known as CRP levels, inflammation begins to go decrease.

Blood Pressure: Starts to come down.

36- 48 hours of Fasting

At this point, your body has settled with not having any incoming glucose, so it will find sugar that it stored a long long time ago.

If you find it difficult to lose weight, 36 hour fasts may do the trick for you. When you hit this mark during a water fast, you force your body to go and find stored sugar and fat.

Here’s what else is happening during the second day of your fast: Ketones continue to go up. You might begin to feel a little dizzy BUT, as your ketones go up, so will GABA production. GABA produces a feeling of calm. It is normal to feel as though you want to lay down and go to bed throughout the day. If you have the freedom and ability to do so, by all means, lay down and go to sleep.

[“GABA is considered an inhibitory neurotransmitter because it blocks/ inhibits, certain brain signals and decreases activity in your nervous system. When GABA attaches to a protein in your brain known as a GABA receptor, it produces a calming effect.”]

Because you have so much BDNF (still) being released, brain repair is heightened during this time.

Overall, day 2 of a (water) fast can bring on some tough times. You may have waves of uncomfortable feelings throughout your fast.  Allow them to come and go. Feelings of tiredness, dizziness, even headaches, and/or pain in other areas of the body may occur.

They are likely side-effects of your body repairing itself. Repair does not always feel great; so, if you need to, take naps or go to bed early and allow the body to heal itself.

72-120 hours of Fasting

Stem cell production is really starting to kick in. If you’re really fat-adapted you may hit this point early (before the 72 hour mark). Others may need all the way up until the 72 hour mark for the stem cells to really kick in.

According to Walter Longo’s research, the primary stem cells that kick in on the 3rd day are from the immune system. Old, useless white blood cells will be recycled and regenerated 72 hours after the start of a water fast. So, if you’re looking to boost your immune system, a 72-120 hour water fast is the way to go. Keeping the body in a fasted state between 3-5 days is a sure-fire way to enter the land of MAXIMUM stem cell, BDFM, and ketone production.

In summary, the first 3 days of water fast is where all of the (beneficial) chemical reactions are initiated. Fasting beyond 3 days allows you to live in a longer healing state. Listen to your body during a water fast. Use your best judgement when deciding how long you’d like to carry on in this healing state.

Bonus

Because you are not getting that dopamine response from reaching for food while fasting, you, in turn, recalibrate your dopamine receptor sites.

Hang in There

If you’re on day 2 of your water fast, hang in there if you can help it! Go back and read this article from the beginning if you must. Miracles are happening inside of you right now. Be proud because are giving yourself an incredible gift.

Click here to learn about the Ultimate benefits of Fasting.

Click here to learn how you can Naturally Balance your Hormones w/ fasting.

*See Medical Disclaimer