The Science of Fasting (1 Viewer)

[Tapxe]

Okay, I found and read this thread over the weekend. I watched the documentary posted by Expat in the OP. Fascinating and almost unbelievable.

I intend to do more research and re-read the thread because of the many good posts.

I'd like to give this a go, but I don't want to do it unsafely and I haven't done the homework. Because of lent I'm attempting a fast for Ash Wednesday (last meal was last night at about 19:00). What are the rules to fasting - just water? Any nuts or broth, etc.?

I'm hoping to go at least 36 hours.

And does someone have a link to the 8-hour eating window that was mentioned earlier?

I'm sure I'll be back with more questions, later - if I don't pass out. Thanks in advance.

Most of what I read said to ease into a fast rather than just cold turkey. That would be reducing calories for a couple days with just light meals or juices/soups before and after.

I'd think 36 hrs would be no problem for most people medically, but you might want to talk to a Dr first especially if you have any medical conditions. I'd probably recommend starting with a 16 hr fast window and 8 hr eating window for a few weeks to work up to the total fasting which yes would be just water or coffee without sugar/cream.

I used this site before even seeing the video get started with lots of info on different methods. YMMV

http://www.allaboutfasting.com/types-of-fasting.html

http://www.allaboutfasting.com/intermittent-fasting.html

FYI, down 40#'s since my heaviest. Was stuck at 210 and 200 for a while, but made it to 189 this morning. My Dr. is going to be impressed as his goal for me was 185, but I think I'll try to get back to 155-160 eventually.

 

[RussTKD]

Care to explain why and your credentials vis a vis the topic? I'd like to know if you are coming from a place of science, experience, or both before I accept as factual your statement.

Speaking scientifically, muscle is metabolically active tissue, whereas fat isn't. Your body will break down muscle protein and burn that for energy when caloric supply isn't sufficient, especially easily accessible fuel, like simple and/or complex carbs.

All the weight training in the world isn't going to put on muscle if you're not feeding your body the nutrients it needs to build and repair muscle tissue.

As for not being able to out-run a bad diet, people grossly overestimate the amount of calories that are burned in an exercise session. On average, an adult only burns 100 calories running a mile. That's not even enough to burn off a 12oz. Coke. You'd have to run 2 miles just to work off a Snickers bar. Swimming is even less efficient at burning calories, hence the guy referenced who was gaining weight as he got older despite swimming 3-4 hours a day.

And what's even worse as far as swimming goes, the better a swimmer you are, the lower your calorie burn per distance swam since you move through the water much more efficiently than a beginner swimmer. Couple that with the fact that your appetite can get voracious after being in 78-80 degree water for a half-hour or so, and it's really easy to out-eat any caloric deficit you've created.

For personal experience, here was my workout Saturday coupled by caloric intake:

I rode a tick under 60 miles Saturday. I was on the bike for 3 hours.

Pre-ride, I ate a double serving of cereal, about 300 calories.
During the ride, I consumed 2 bottles of Infinit, roughly 600 calories or so.

According to my Garmin, my calorie burn was around 1400 calories, so my caloric deficit was only 500, which I completely used up with the second chicken sandwich I had for lunch.

My BMR (Basal Metabolic Rate) is probably 1500 calories or so, give or take 100 calories, as I'm a small guy. That was probably less than my dinner (2 Big Easy IPAs, fried calamari, cup of gumbo, catfish po-boy, slice of king cake).

Someone who doesn't track caloric intake might be shocked to learn that an intense bike ride only yields around 470 calories burned per hour.

I've tried training on an empty stomach. It doesn't work. At all. I can't hit my interval numbers, I'm sluggish, and as proof of my body catabolizing my muscle tissue, all my workout clothes smell like ammonia after I'm done (byproduct of muscle breakdown during exercise). You NEED to fuel your body to exercise. You need to eat to gain muscle. Period. And while you can't "out run" a bad diet, most people are ignorant as to how quickly your bad diet can wreck any progress you make from training. If they knew, maybe they'd stop with the XL Mocha Latte and muffin the size of their head after their 45 minute Zumba class.

Want further proof? Watch body-builders eat. The Rock has a video or 8 about his eating when he's bulking.

This isn't to say whether or not fasting with do anything with weight loss. But trying to claim muscle mass is a function of exercise and not diet is absolutely ridiculous, and using an endurance athlete as proof is also foolish.

 

[Tapxe]

Speaking scientifically, muscle is metabolically active tissue, whereas fat isn't. Your body will break down muscle protein and burn that for energy when caloric supply isn't sufficient, especially easily accessible fuel, like simple and/or complex carbs.

All the weight training in the world isn't going to put on muscle if you're not feeding your body the nutrients it needs to build and repair muscle tissue.

As for not being able to out-run a bad diet, people grossly overestimate the amount of calories that are burned in an exercise session. On average, an adult only burns 100 calories running a mile. That's not even enough to burn off a 12oz. Coke. You'd have to run 2 miles just to work off a Snickers bar. Swimming is even less efficient at burning calories, hence the guy referenced who was gaining weight as he got older despite swimming 3-4 hours a day.

And what's even worse as far as swimming goes, the better a swimmer you are, the lower your calorie burn per distance swam since you move through the water much more efficiently than a beginner swimmer. Couple that with the fact that your appetite can get voracious after being in 78-80 degree water for a half-hour or so, and it's really easy to out-eat any caloric deficit you've created.

For personal experience, here was my workout Saturday coupled by caloric intake:

I rode a tick under 60 miles Saturday. I was on the bike for 3 hours.

Pre-ride, I ate a double serving of cereal, about 300 calories.
During the ride, I consumed 2 bottles of Infinit, roughly 600 calories or so.

According to my Garmin, my calorie burn was around 1400 calories, so my caloric deficit was only 500, which I completely used up with the second chicken sandwich I had for lunch.

My BMR (Basal Metabolic Rate) is probably 1500 calories or so, give or take 100 calories, as I'm a small guy. That was probably less than my dinner (2 Big Easy IPAs, fried calamari, cup of gumbo, catfish po-boy, slice of king cake).

Someone who doesn't track caloric intake might be shocked to learn that an intense bike ride only yields around 470 calories burned per hour.

I've tried training on an empty stomach. It doesn't work. At all. I can't hit my interval numbers, I'm sluggish, and as proof of my body catabolizing my muscle tissue, all my workout clothes smell like ammonia after I'm done (byproduct of muscle breakdown during exercise). You NEED to fuel your body to exercise. You need to eat to gain muscle. Period. And while you can't "out run" a bad diet, most people are ignorant as to how quickly your bad diet can wreck any progress you make from training. If they knew, maybe they'd stop with the XL Mocha Latte and muffin the size of their head after their 45 minute Zumba class.

Want further proof? Watch body-builders eat. The Rock has a video or 8 about his eating when he's bulking.

This isn't to say whether or not fasting with do anything with weight loss. But trying to claim muscle mass is a function of exercise and not diet is absolutely ridiculous, and using an endurance athlete as proof is also foolish.

I think you may be confusing people interested in weight loss and people interested in body building. I don't doubt that you'd need to eat to build muscle, but most folks in this thread are interested in losing fat. From what I've read, the muscle loss is not significant for an average person just looking to get to a healthy weight.

 

[Madmarsha]

Okay, I found and read this thread over the weekend. I watched the documentary posted by Expat in the OP. Fascinating and almost unbelievable.

I intend to do more research and re-read the thread because of the many good posts.

I'd like to give this a go, but I don't want to do it unsafely and I haven't done the homework. Because of lent I'm attempting a fast for Ash Wednesday (last meal was last night at about 19:00). What are the rules to fasting - just water? Any nuts or broth, etc.?

I'm hoping to go at least 36 hours.

And does someone have a link to the 8-hour eating window that was mentioned earlier?

I'm sure I'll be back with more questions, later - if I don't pass out. Thanks in advance.

You won't pass out, remember, Hunger is not an emergency.

I just did a 24 hour. I wanted to go 36, too, but it's hard. Best if you "step up" to it. In fact, I can't really make it past 36 hours.

For me, right now, I can do 16-18 easy. Nothing but water and decaf coffee with HWC, no sweetener. Getting to 24 was a matter of white knuckling it and keeping myself distracted and "filling up" on the water.

24 to 36 is where it gets interesting. I just decided to pack it in; but if you really want to go the distance, then you can do broth. It's better not to but it may be the difference between getting there or not. But, like I said, it's okay to step up to it.

If you want to go 36 but end up "only" going 24, that's fine. It's not a failure. You have to listen to your body and whatever else is going on externally.

For me, at 36 hours, I start missing the act of eating. And that's what does me in more than the hunger. And I like the idea of giving my body a "rest", letting it truly fully digest, letting my BS subside, making sure my body is fat adapted and is utilizing those saved fat stores.

 

[RussTKD]

I think you may be confusing people interested in weight loss and people interested in body building. I don't doubt that you'd need to eat to build muscle, but most folks in this thread are interested in losing fat. From what I've read, the muscle loss is not significant for an average person just looking to get to a healthy weight.

Right, but I was refuting the claim the quoted author made that “exercise builds muscles, not diet”. It’s simply not true in the least.

 

[Tapxe]

Right, but I was refuting the claim the quoted author made that “exercise builds muscles, not diet”. It’s simply not true in the least.

You can eat the perfect meal everytime, but if you don't exercise properly you won't build muscle. For optimal results you need both for sure.

 

[SoggyBottomBoy]

You won't pass out, remember, Hunger is not an emergency.

I just did a 24 hour. I wanted to go 36, too, but it's hard. Best if you "step up" to it. In fact, I can't really make it past 36 hours.

For me, right now, I can do 16-18 easy. Nothing but water and decaf coffee with HWC, no sweetener. Getting to 24 was a matter of white knuckling it and keeping myself distracted and "filling up" on the water.

24 to 36 is where it gets interesting. I just decided to pack it in; but if you really want to go the distance, then you can do broth. It's better not to but it may be the difference between getting there or not. But, like I said, it's okay to step up to it.

If you want to go 36 but end up "only" going 24, that's fine. It's not a failure. You have to listen to your body and whatever else is going on externally.

For me, at 36 hours, I start missing the act of eating. And that's what does me in more than the hunger. And I like the idea of giving my body a "rest", letting it truly fully digest, letting my BS subside, making sure my body is fat adapted and is utilizing those saved fat stores.

Still going. 38 hours into it. Just water with the exception of a wafer of Eucharistic host at mass, yesterday. Probably going to break the fast at lunch today. Trying to figure out what type of meal to have today. Expat's links were very informative. I'll go into more detail later, but after reading on it some more, I've been kinda eating in a smaller window already - I'm a breakfast skipper. So, I've been semi-preparing for this.

Right now, I'm just listening to my body and trying not to be stupid with this first foray into fasting. I'm trying to sort out how I feel. Strangely, a little light headed, but with more clarity, if that makes sense. It hasn't been easy, but not nearly as hard as I thought. I really thought I'd buckle in sooner mainly because water is so boring.

Right, but I was refuting the claim the quoted author made that “exercise builds muscles, not diet”. It’s simply not true in the least.

You can eat the perfect meal everytime, but if you don't exercise properly you won't build muscle. For optimal results you need both for sure.

What I gathered from the doctor's quote was that you can't gain muscle purely from what you eat. You can't go to GNC, buy some powdered shake to drink and you'll grow muscles. You have to work out or exercise to build muscles. Yes, the muscle growth/development has to be fed by a diet (like the rest of our body) but without exercise wouldn't a particular muscle friendly diet just maintain rather than grow or add muscle tissue?

 

[RussTKD]

What I gathered from the doctor's quote was that you can't gain muscle purely from what you eat. You can't go to GNC, buy some powdered shake to drink and you'll grow muscles. You have to work out or exercise to build muscles. Yes, the muscle growth/development has to be fed by a diet (like the rest of our body) but without exercise wouldn't a particular muscle friendly diet just maintain rather than grow or add muscle tissue?

The doctor says straight up you won’t burn muscle by fasting. That’s false.

The doctor says muscle is a result of exercise, and not diet. Also false. It’s a symbiotic relationship between the two.

 

[SWJJ]

SO after splurging and consuming too many calories on 3 of my consecutive eating windows (All involved drinking too much alcohol) I gained 2 pounds back in the last week. I am 12 hours into a 48 hour fast. I'll reweigh on monday and post an update.

 

[zeetes]

The doctor says straight up you won’t burn muscle by fasting. That’s false.

The doctor says muscle is a result of exercise, and not diet. Also false. It’s a symbiotic relationship between the two.

i think it can be looked at both ways. my wife was sick for years and it made me learn what i could about what could be done to prevent muscle burn, and this is basically how i know it. it has been a few years, so i may be a little off, but i'm fairly confident this is how it goes:

the human body burns glycogen (glycolysis) and fat (ketosis), before muscle atrophy. a person with muscle degradation is malnourished, or has a deadly disease, and should not be fasting. common with very high protein and little to no carb or fat diets.

muscle growth requires simply protein and exercise, on top of what is needed to maintain growth. for this, the body needs just enough carbs and fat to prevent the amino acids within muscle from being converted into glucose, enough protein, converted into essential and non-essential amino acids, depending on the organ, and to replenish those that have been used (we pee/sweat out excess).

 

[kevin from buffalo]

i think it can be looked at both ways. my wife was sick for years and it made me learn what i could about what could be done to prevent muscle burn, and this is basically how i know it. it has been a few years, so i may be a little off, but i'm fairly confident this is how it goes:

the human body burns glycogen (glycolysis) and fat (ketosis), before muscle atrophy. a person with muscle degradation is malnourished, or has a deadly disease, and should not be fasting. common with very high protein and little to no carb or fat diets.

muscle growth requires simply protein and exercise, on top of what is needed to maintain growth. for this, the body needs just enough carbs and fat to prevent the amino acids within muscle from being converted into glucose, enough protein, converted into essential and non-essential amino acids, depending on the organ, and to replenish those that have been used (we pee/sweat out excess).

this is why I try to drink plenty of water for my arthritic back..if my muscles get tight back there..the spasms are brutal.

 

[Madmarsha]

been kinda eating in a smaller window already - I'm a breakfast skipper. So, I've been semi-preparing for this

Same here. Sleeping and then getting going without breakfast is why 16-18 is easy for me. I always get a good start on my water in the morning which helps not only "filling" my stomach up but gives me something to do with my hands.

Right now, I'm just listening to my body and trying not to be stupid with this first foray into fasting. I'm trying to sort out how I feel. Strangely, a little light headed, but with more clarity, if that makes sense. It hasn't been easy, but not nearly as hard as I thought. I really thought I'd buckle in sooner mainly because water is so boring

Very good. Yeah, it's odd that, as an otherwise healthy person, you think it's going to be your BS bonking and crashing is what's going to get you and it's not. It makes you super aware, gives you a weird energy, teaches you that what we perceive a lot of times as hunger truly isn't, it's a lot of times boredom or being dehydrated.

 

[SoggyBottomBoy]

Same here. Sleeping and then getting going without breakfast is why 16-18 is easy for me. I always get a good start on my water in the morning which helps not only "filling" my stomach up but gives me something to do with my hands.

Very good. Yeah, it's odd that, as an otherwise healthy person, you think it's going to be your BS bonking and crashing is what's going to get you and it's not. It makes you super aware, gives you a weird energy, teaches you that what we perceive a lot of times as hunger truly isn't, it's a lot of times boredom or being dehydrated.

You won't believe this, but I'm still going. 61 hours. 72 feels doable. If I make that (7pm) I'm definitely breaking the fast, then. Did I mention that water is boring? Well, it is.

 

[SoggyBottomBoy]

Done. Ate this evening. 73 hours.

 

[Madmarsha]

You won't believe this, but I'm still going. 61 hours. 72 feels doable. If I make that (7pm) I'm definitely breaking the fast, then. Did I mention that water is boring? Well, it is.

I used to be one of those "I hate water" people, but I've embraced it because I know I never used to drink enough.