What Happened To My Body During My 48 Hour Fast

After hearing about all of the great benefits associated with fasting, I decided I wanted to put it to the test by doing my own 48 hour fast. This is the story of what happened to my body in what turned out to be the 52 hours that I gave up food.

I decided to begin my fast on a Tuesday afternoon, right after lunch. I woke up in the morning, and documented where I was at. When it came to my weight, in all honesty I was slightly bloated at this point. I was retaining more water than normal because I had a higher than normal salt intake on Sunday, but my weight was 195.2 pounds.

My blood pressure was 122/76 and my Ketones tested at zero.

I decided to skip breakfast to try and deplete my glycogen stores to prepare for my fast, this was so my body could start producing ketones faster, but more on that in a bit. I decided to still eat lunch, because it was taco tuesday and I really didn’t want to miss that. I finished lunch at 11:32AM and the fast was officially underway.

Through this experiment, I continued to exercise, obviously on this first night I didn’t really notice any difference in my performance at this point. Just slightly hungry throughout the night.

Around midnight, 12 hours into the fast, this is when some of the magic of fasting starts to happen. After fasting for 12 hours, Growth Hormone kicks in. Growth Hormone is what helps you to burn fat, build muscle and slows down the aging process. When you start fasting, your body can see a 1300% increase in the production of growth hormone. This is great, because after you reach 30 years of age, your body produces less and less growth hormone. So fasting helps you to produce more.

A few hours later (13 to 15 hours into the fast), the body realizes no food is coming in and begins to make a change from burning sugar for fuel, to burning fat for fuel. This is when the body starts to produce Ketones, the mechanism that your body uses to burn fat as a fuel source. For those wanting to lose fat, this is the stage you want to be in. The more ketones you have in your system, the more healing takes place in your cells and in your brain.

Right around the time I wake up (17 hours into the fast) my body is entering into the Autophagy phase, this is the self healing phase and you can think of it as a detox phase. Your cells realize that your blood sugars going down, and begins to look for energy within itself by eating the toxins within it. Autophagy will max out at about 72 hours, and will continue from there. This is when your body starts to detoxify itself. Also the ketone production in the body is increasing.

My weight for this first morning of the fast was 192 pounds and my ketone levels are at 4.0.

As lunch time rolls around, I hit the 24 hour mark of this fast. I keep going through periods where I'm incredibly hungry, but they pass after a short bit. Now is the time to hold strong, because this is when a lot of the magic really begins to take place.

At the 24 hour period of a fast, intestinal stem cells start to regenerate. This is great for fixing issues like leaky gut.

Your body also starts to create more of a protein called BDNF. BDNF is great for the brain, it will repair damaged neurons and can help with issues like memory loss, lack of focus and depression.

Your Serotonin levels also go up, this is the chemical that makes you happy! Inflammation in the body also starts to decrease and your blood pressure begins to go down.

So at 24 hours into a fast, a whole lot is beginning to happen, this is just from one day of not eating.

As the next morning rolls around I’m hitting the 36 to 48 hour point of the fast, my weights down to 188.8 and my ketone production is now a 16, this is as high as my testing strips measure and best of all, more benefits are kicking in.

Now that my body really notices that I am not getting any new sugars and begins searching for stored sugars within the fat my body stored years ago, this is why my ketones are so high now.

Also the neuron repair in the brain is really ramping up. This can cause some dizziness as well as tiredness. I noticed that I had a slight, dull headache for most of the day, but it wasn’t terrible, I also feel like going to bed earlier than normal.

So technically I hit the 48 hour mark while I was at work, so I couldn’t weigh myself to find my results, so I held off eating for a little longer, but this is great because white blood cells in my body are starting to get recycled and regenerated, this causes a boost in your immune system.

Stem Cell production is also really high now which is helping repair various issues within the body.

I weighed in at 188.4 pounds and definitely saw my waistline shrink in size.

I saw my BMI go from 27.9 to 27

My body fat go from 23.2 % to 21.7%

My subcutaneous fat as well as my visceral fat also dropped and my metabolic age lowered.

My blood pressure also improved, going from 122 /76 to 117 over 76.

[SimpleManChannel]

Thanks for watching everyone, it’s much appreciated!

[toothpastehombre]

You really did your research here, impressive detail and explanation. Thank you

[saiken]

That's great man! Started keto and IF about one and a half month ago. Began with 16/8 and switched to omad 2 weeks ago and I've lost 10kg already. Now I am trying to prep myself for my first 48 hr fast and your vid helps a lot!

[marines]

Good stuff, man. Thanks for being chill and being normal in you videos. Just straight to the points, facts, logic, and concise. Thanks!

[DookeyRidr]

I did 45 days of 72 hour fasts in succession. I lost 37 lbs, I slept better every night, my inflammation went away, my blood pressure went from pre-hypertensive to the lowest I’ve ever seen it recorded (105/63), my HRV was the highest ever recorded (on my Oura ring), and my resting heart rate was the lowest ever. Huge benefits.

[RamirezTwins]

Currently at hour 36, 1st fast ever, I feel, pretty good....your commentary was pretty funny, keep it up

[beeisbad]

Thank you for the depth AND simplicity in your explanation of 48hr fasting, bro!

[melanier]

Great video! Very informative and with animation. I’m currently on a 48 hour fast.

[Blaine]

Thank you for a great video!! Finally a concise, to the point video of what happens during a fast!!! All the other videos constantly digress to medical terminology and what foods to use. Appreciate your effort. I’ve been doing 20 hour fast for 2 weeks and lost 8 pounds. Also doing the keto diet with the fast. I’m definitely doing the 48 hour fast!!

[marktownsend]

I must say, I thought that was brilliant; straight to the point, honest and very informative....I'm at 24 right now and am going for 48 at least...I've been doing a 24 hr fast for a week, but now ramping up...Thank you and very well done fella>>

[rosanne]

You walking around that peanut butter jar and sniffing it is just me every day tbh

[ryancouch]

I’ve done some 16/8 intermittent fasting. You inspired me to try a 24 hour fast thanks Simple Man!!!

[slowjamcdub]

Great video!!!! I’m 30 hours in and going strong! Any tips to make it the rest of the way?💪🏻🙏👏👍

[DeafSeattleGuy]

Hey Dude! I just started my 2nd day of 16:8 Intermittent Fasting. It's amazing (so far). I plan on doing it slowly then will gradually get to 72 hour fasts (my goals). Your posts are always so inspiring and it's captioned! Thank you!

[kribz]

I’ve been doing intermittent fasting on and off for around 7-8 months now and it really helps to loose weight, especially if you add in some exercises every other day.

[rcoles]

Awesome mate, I'm 1/2 way through a 48hr fast and this video has really pumped me back up to finish.

I just had to watxh my son and wine eat a dinner I cooked for them and almost caved. Glad I didn't now :-)

[cheapflights]

Great, detailed explanation. Thank you. The human body is a very complex and clever machine I understand it much better now.

[danbee]

John Meadows a extremely knowledge person in fitness, said that fasting is particuarly great for sorting out digestion and help to absorb more nurtients as the digestive tracts beigns to repair during fasting period. He did a video on the matter.

[jameswoodall]

Made in a light-hearted way but very accurate! Keep it up. Simple Man is also Everyday Man.

[medzlopez]

Hi Simple Man. I learned a lot from this especially the JIF peanut butter. Seriously I'll replicate what you just did!