The science of intermittent fasting

[Afro_Vacancy]

I'm doing my first multi-day fast.

Had dinner on the evening of August 1st.
August 2nd, 86.8 Kg, 191.3 lbs
August 3rd, 84.6 Kg, 186.5 lbs

I lost 5 lbs in the first day, which is clearly water weight, probably 4 lbs of water weight and 1 lbs of fat weight, approximately. On the second day I might lose 1 lbs, we'll see, I'm at ~39 hours now and all of the fasts I've done so far have been ~36 hours. I feel totally fine. Incidentally I got my blood pressure taken this morning and it was ~116/79. I wonder if I'll get an energy surge tomorrow or the day after?

Saturday morning and Sunday morning I have social events, so the longest my fast can go is ~108 hours or 4.5 days. I might do another one next week depending on how this goes. The hardest aspect, as I've stated before, is the anti-social aspect. Fasting rules out most social activities in our food-driven culture.

 

[Afro_Vacancy]

Had dinner on the evening of August 1st.
August 2nd, 86.8 Kg, 191.3 lbs
August 3rd, 84.6 Kg, 186.5 lbs
August 4th, 83.6 kg, 184.3 lbs

I'm now up to ~60 hours of fasting. Interestingly, I still lost water weight in the period between 36 and 60 hours, roughly ~0.5 Kg or 1 lbs of water weight.

 

[kj6723]

Had dinner on the evening of August 1st.
August 2nd, 86.8 Kg, 191.3 lbs
August 3rd, 84.6 Kg, 186.5 lbs
August 4th, 83.6 kg, 184.3 lbs

I'm now up to ~60 hours of fasting. Interestingly, I still lost water weight in the period between 36 and 60 hours, roughly ~0.5 Kg or 1 lbs of water weight.

60 hours fasting...Damn dude, that's some serious fortitude. The one meal a day thing is still working well for me. This past week though I've found myself having to pull back a bit during my meal, as my hunger hits me hard and I've been close to borderline binging.

 

[Afro_Vacancy]

60 hours fasting...Damn dude, that's some serious fortitude. The one meal a day thing is still working well for me. This past week though I've found myself having to pull back a bit during my meal, as my hunger hits me hard and I've been close to borderline binging.

If you're eating one meal a day which is not high in simple carbs I would think that it would be extremely hard to gain weight.

I might do 1 or 2 meals a day for "maintenance" when I'm done. Right now I'm trying to cut, to cut fast. I'm also experimenting with the prolonged fasting protocol, there are so many people who fast for 10, 20, 30 days and report great benefits, the longest I had done is 36 hours. With that said I'm eating on Friday morning (tomorrow morning) so this will come out to ~3.5 days.

How long have you been practicing your fasting protocols, and what results have you had with it? Did you try other methodologies prior to that?

 

[kj6723]

If you're eating one meal a day which is not high in simple carbs I would think that it would be extremely hard to gain weight.

I might do 1 or 2 meals a day for "maintenance" when I'm done. Right now I'm trying to cut, to cut fast. I'm also experimenting with the prolonged fasting protocol, there are so many people who fast for 10, 20, 30 days and report great benefits, the longest I had done is 36 hours. With that said I'm eating on Friday morning (tomorrow morning) so this will come out to ~3.5 days.

How long have you been practicing your fasting protocols, and what results have you had with it? Did you try other methodologies prior to that?

I've done the one meal a day thing on and off a few times in the past, probably for a couple months straight at the most(don't remember specific timelines). This time around, I'd say I've been doing it for about 2-3 months. I body fat was fairly low before I started, but I've still managed to drop about 10 pounds in that time, while still making small strength gains(don't care to gain much, I'm pretty happy with my muscle mass and don't want to add much size apart from a few areas I'm "perfecting"). I find 1 meal a day allows me to maintain low body fat while still being able to enjoy a hearty meal every day. I plan to continue with it for the foreseeable future.

I'm not technically full on fasting. I start off my day with a banana for a boost of energy before working out, and I still aim to consume 20-30 grams of protein roughly every three hours when I'm awake, as well as some vegetables. This is roughly what a typical day for me looks like:

wake up: banana
work out
protein shake
2.5-3 hours later: leftover meat and vegetables in fridge
2.5-3 hours later: protein shake
2.5-3 hours later: GLORIOUS DINNER
before bed: casein protein shake

I stick to this Monday-Friday

As far as other methodologies I've used....I used to always do the "bulk up" and then "cut" thing, but since I'm at a BMI I'm pretty happy with maintaining, I'd rather have a way of living and eating I can just keep doing indefinitely without having to worry about getting my body ready for "beach season" or whatever. I'd rather just look my best 24/7 365 days a year, and so far the 1 meal a day thing seems to be working in that regard.

 

[Afro_Vacancy]

I've done the one meal a day thing on and off a few times in the past, probably for a couple months straight at the most(don't remember specific timelines). This time around, I'd say I've been doing it for about 2-3 months. I body fat was fairly low before I started, but I've still managed to drop about 10 pounds in that time, while still making small strength gains(don't care to gain much, I'm pretty happy with my muscle mass and don't want to add much size apart from a few areas I'm "perfecting"). I find 1 meal a day allows me to maintain low body fat while still being able to enjoy a hearty meal every day. I plan to continue with it for the foreseeable future.

I'm not technically full on fasting. I start off my day with a banana for a boost of energy before working out, and I still aim to consume 20-30 grams of protein roughly every three hours when I'm awake, as well as some vegetables. This is roughly what a typical day for me looks like:

wake up: banana
work out
protein shake
2.5-3 hours later: leftover meat and vegetables in fridge
2.5-3 hours later: protein shake
2.5-3 hours later: GLORIOUS DINNER
before bed: casein protein shake

I stick to this Monday-Friday

As far as other methodologies I've used....I used to always do the "bulk up" and then "cut" thing, but since I'm at a BMI I'm pretty happy with maintaining, I'd rather have a way of living and eating I can just keep doing indefinitely without having to worry about getting my body ready for "beach season" or whatever. I'd rather just look my best 24/7 365 days a year, and so far the 1 meal a day thing seems to be working in that regard.

Sounds like things are working well for you and you have a good plan. How often do you have breakfast or lunch for social reasons?

When I was working out first thing in the mornings, I was doing so in a fasted state and then eating a good meal right afterwards. I did a scan of the literature on eating just before a workout, just after a workout, etc and in general the literature is quite poor. A lot of contradictory studies with small sample sizes, et cetera.

One of the few consistent findings is that it's a good idea for a many to eat 100-150 grams a day of protein, the need is higher when one is starting to build. If one is already built, protein needs are lower, which I found interesting but in hindsight obvious.

The GLORIOUS DINNER is without a doubt a benefit of fasting. If you're following the 1990s-era advice of having six small meals a day, you never get to have a great meal. That sounds depressing. As it is now, I can push away the psychological hunger as I expect a glorious dinner tomorrow night, and a glorious breakfast the morning after, both are social outings.

 

[kj6723]

Sounds like things are working well for you and you have a good plan. How often do you have breakfast or lunch for social reasons?

Lol rarely. My social life is very sub-par at the moment. Occasionally I'll go out to breakfast with my parents, but on Saturday, which is an off day from the diet.

When I was working out first thing in the mornings, I was doing so in a fasted state and then eating a good meal right afterwards. I did a scan of the literature on eating just before a workout, just after a workout, etc and in general the literature is quite poor. A lot of contradictory studies with small sample sizes, et cetera.

One of the few consistent findings is that it's a good idea for a many to eat 100-150 grams a day of protein, the need is higher when one is starting to build. If one is already built, protein needs are lower, which I found interesting but in hindsight obvious.

The GLORIOUS DINNER is without a doubt a benefit of fasting. If you're following the 1990s-era advice of having six small meals a day, you never get to have a great meal. That sounds depressing. As it is now, I can push away the psychological hunger as I expect a glorious dinner tomorrow night, and a glorious breakfast the morning after, both are social outings.

Knowing the big meal is around the corner is what makes it doable. I have desert every day, and my stomach still looks like it's photoshopped with popping 300esq abs

 

[Afro_Vacancy]

Had dinner on the evening of August 1st.
August 2nd, 86.8 Kg, 191.3 lbs
August 3rd, 84.6 Kg, 186.5 lbs
August 4th, 83.6 kg, 184.3 lbs
August 5th, 82.3 Kg, 181.4 lbs

I'm surprised by how much water weight I lost in day 3 -- about 2 lbs. I did in fact chain drink tea yesterday, so that's probably the reason.

My fast is over. I had a significant breakfast this morning: small container of mixed fruit, 500 ml of warm milk mixed with honey, and some nuts. So that's about ~800 calories, lol.

Overall the fast was pretty easy, but I did no exercise (obviously), and it's an anti-soial thing to do. I might do a few more multi-day fasts, but I don't want to do them regularly.

 

[Afro_Vacancy]

One physiological side-effect I'm noticing now is intense thirst.

It is well-known that equilibrium water weight is higher when one is getting energy from glucose than when one is getting energy from fat.

For the past three days, I was getting energy from fat and thus I lost 7 lbs (~3.1 Kg) of water in 3 days despite continuously drinking. I can assure you that I was drinking a ton, but the body's equilibrium is for lower water retention when fat burning. In spite of excreting tons of water, I was not thirsty.

Today, my body is returning to a glucose-burning state, and even though I am continuously drinking, I am nonetheless continuously thirsty. It's a stronger thirst than I've felt in a long time.

All of this to say, it is pleasing to see how adaptive the human body is.

ETA: I neglected to say, I am assuming that fat loss is approximately 1 lbs per day, which is well-backed by various studies.

ETA #2: I'll add, this is why I don't buy most people saying "hydration is important, remember to drink water". Perhaps if you're 75 years old and your senses are failing. But in general I don't need to remember to drink. The body tells me to go to drink quite naturally. For that matter I don't need to remember to breathe either.

 

[Afro_Vacancy]

We need to breathe? Forgot. LOL.

Good post. So, what is your theory on fasting?

The human body is evolved to efficiently deal with feast and fast cycles.

When not fasting and simply going "low-calorie", reduce sugar and anything that raises insulin as much as possible. Sugar raises insulin, and high insulin prevents your body from metabolizing its own fat reserves for energy.

 

[kj6723]

I'm thinking that towards the end of this week I may take a break for like 3-4 days...lately I've been having a hard time not completely binging out for my dinner.

 

[Afro_Vacancy]

I'm thinking that towards the end of this week I may take a break for like 3-4 days...lately I've been having a hard time not completely binging out for my dinner.

Take it easy.

 

[Afro_Vacancy]

May 21st, 2016, 88.3 Kg, 194.7 lbs
May 28th 2016, 88.6 Kg, 195.3 lbs
June 4th, 2016, 87.2 Kg,192.2 lbs
June 11th, 2016, 87.3 Kg, 192.5 lbs
June 20th, 2016, 87.1 Kg, 192.1 lbs
June 25th, 2016, 85.6 Kg, 188.7 lbs
July 2nd, 2016, 85.3 Kg, 188.1 lbs
July 9th, 2016, 85.3 Kg, 188.1 lbs
July 17th, 85.3 Kg, 188.1 lbs
July 30th, 84.3 kg, 185.8 lbs
August 3rd, 84.6 Kg, 186.5 lbs
August 4th, 83.6 kg, 184.3 lbs
August 5th, 82.3 Kg, 181.4 lbs
August 9th, 82.9 Kg, 182.7 lbs

Was a straightforward fast on Tuesday. Instead of getting a little hungry around lunch time, I got a little hungry around dinner.

 

[Senku]

Sorry, new member here!

I've been reading this thread and thought wow a lot of things I have been doing have been quite different. My dad had always fed me quite a ton of carbs... but I've been living off of 3 meals a day as usual. Upon reading this I feel like I should try to fast now. However, I've always been told that breakfast was always an important meal to have because that's when our body absorbs nutrients better?(no source, going by word of mouth). So how do we fast more than 24 hours when we're skipping the most important meal of the day?

 

[Afro_Vacancy]

Sorry, new member here!

I've been reading this thread and thought wow a lot of things I have been doing have been quite different. My dad had always fed me quite a ton of carbs... but I've been living off of 3 meals a day as usual. Upon reading this I feel like I should try to fast now. However, I've always been told that breakfast was always an important meal to have because that's when our body absorbs nutrients better?(no source, going by word of mouth). So how do we fast more than 24 hours when we're skipping the most important meal of the day?

The idea of breakfast as the most important meal of the day doesn't hold up well.

People have looked into the studies on which the claim is based and they're not robust.

Aside from that, even if it were, skipping a single breakfast won;t hurt you unless you're doing a physical job.

 

[Senku]

The idea of breakfast as the most important meal of the day doesn't hold up well.

People have looked into the studies on which the claim is based and they're not robust.

Aside from that, even if it were, skipping a single breakfast won;t hurt you unless you're doing a physical job.

Is there a fine balance between fasting and exercising? Also, can I survive just on apple cider vinegar + water when I'm fasting?

How about green tea?

 

[Afro_Vacancy]

Is there a fine balance between fasting and exercising? Also, can I survive just on apple cider vinegar + water when I'm fasting?

I'm not sure what the point of taking vinegar when not eating is? I thought vinegar was good specifically for its effects on the digestive system. So, imo, take vinegar with food, or just before food.

How long do you plan on making your fasts?

Water is of course essential. Tea and coffee are good too.

I do not recommend exercise while fasting. Keep in mind that though your body can easily make glucose and ketones from its own fat, it cannot make proteins or amino acids. Amino acids contain a nitrogen atom, which cannot be found in fats or carbs, so they are actually their own separate unit. If you exercise during fasting, I (and others) recommend exercising at or near the end of the fast, such that you're eating right after.

 

[Senku]

I'm not sure what the point of taking vinegar when not eating is? I thought vinegar was good specifically for its effects on the digestive system. So, imo, take vinegar with food, or just before food.

How long do you plan on making your fasts?

Water is of course essential. Tea and coffee are good too.

I do not recommend exercise while fasting. Keep in mind that though your body can easily make glucose and ketones from its own fat, it cannot make proteins or amino acids. Amino acids contain a nitrogen atom, which cannot be found in fats or carbs, so they are actually their own separate unit. If you exercise during fasting, I (and others) recommend exercising at or near the end of the fast, such that you're eating right after.

Ah I see so that makes sense. So I can either go with green tea or black coffee I suppose while I fast. Because I was wondering if we're not eating, how else would we get our energy to do our daily activities right.

Since this will be my first time, I'll try to go for the maximum to see my limit and then lower the threshold from there. So I guess I'll fast for 36 hours and see how well I'll do. But why does it have to be at 36 hours?

 

[Afro_Vacancy]

Ah I see so that makes sense. So I can either go with green tea or black coffee I suppose while I fast. Because I was wondering if we're not eating, how else would we get our energy to do our daily activities right.

Since this will be my first time, I'll try to go for the maximum to see my limit and then lower the threshold from there. So I guess I'll fast for 36 hours and see how well I'll do. But why does it have to be at 36 hours?

When you don't eat, your body slowly activates extracting energy from your body fat. That's what your body fat is: a battery. A reserve battery for when you're not eating.

Technically, this takes 4-days to fully activate apparently, but not a lot of news do 4-day fasts. I'd like to try one soon ... apparently on the 5th day people feel full of energy.

It doesn't "have" to be any particular length. 36 hours is just convenient for me and that's what I do. I would do longer than 36 hours but I'm not willing to sacrifice coffee/drinks/dinner with friends. I would like to schedule a longer fast.

Among the different protocols people do:
- "8-hour eating window", where you eat your food within 8 hours, for example skip breakfast and have lunch and dinner;
- 4-hour eating window, same idea;
- 36 hour fasts, 42 hour fasts (wait until lunch on second day);
- long-term fasts, which I think is 7+ days;

I would like to try 7+ days at some point.

Warning: if you lose 10 lbs, you probably need to spend money on new clothes.

 

[Senku]

When you don't eat, your body slowly activates extracting energy from your body fat. That's what your body fat is: a battery. A reserve battery for when you're not eating.

Technically, this takes 4-days to fully activate apparently, but not a lot of news do 4-day fasts. I'd like to try one soon ... apparently on the 5th day people feel full of energy.

It doesn't "have" to be any particular length. 36 hours is just convenient for me and that's what I do. I would do longer than 36 hours but I'm not willing to sacrifice coffee/drinks/dinner with friends. I would like to schedule a longer fast.

Among the different protocols people do:
- "8-hour eating window", where you eat your food within 8 hours, for example skip breakfast and have lunch and dinner;
- 4-hour eating window, same idea;
- 36 hour fasts, 42 hour fasts (wait until lunch on second day);
- long-term fasts, which I think is 7+ days;

I would like to try 7+ days at some point.

Warning: if you lose 10 lbs, you probably need to spend money on new clothes.

Wow very informative! Thank you for taking the time to answer back! I am truly inspired by your posts and your journey. And for that, I will test my body to the limits even further starting from today. After I have my lunch, I will fast until Monday for a total of 72 hours and see how my body will react.

I've read somewhere online saying that fasting should also be taken at a slow pace to allow our body to get use to the conditions. I have been fasting actually without knowing for 15-18 hours daily so I think I can pull off a 72 hour fast by drinking water/black coffee. I will update and post up any results I find interesting regarding my body.

Oh I definitely hear you on the new clothes! I have been on and off with my weight but finally I was able to drop from 215 lbs to 155 lbs. Went from waist size 34 to 29-31~ish. I just did ate a lot healthier, and didn't eat anything after 5pm. Moderate exercise including skipping rope/jogging/push ups. I think with fasting and eating 1 meal a day will drastically decrease my weight. Not sure about my weight being healthy by then.. I'm 180 cm tall