Intermittent Fasting Support Group?

chrisdavey

I started doing every-other-day Intermittent Fasting about 3 weeks ago, at that time not having heard of LeanGains or Eat Stop Eat. I did it based on research I read about its effectiveness in animal studies at lengthening lifespan and improving blood health markers, and also because I noticed one day that I was about 20 lbs over my ideal weight and past 25 BMI. I figured it was worth a try, and I haven't looked back or even lost step since I started. It's very surprising how much easier it is than I though it would be.

About a week ago I did buy "Eat Stop Eat" as I was doing research so I could defend my new diet to friends and family (veteran dieters, many of them, who are afraid of the dreaded Starvation Mode). Since Mr. Pilon's only caution against doing more than two days a week is that it reduces flexibility in the diet, and I had no problem with that whatsoever, I just continued with my alternating days thing.

I've been getting good results so far. Lost about 10 lbs, and insofar as I can tell from my inexpert use of a fat caliper, almost all of that has been body fat, and my lean mass has stayed about the same (doing mostly body weight exercises to keep up muscle). The caliper measurements have a lot of variance when taken by an amateur like me, but the trend still seems significant, and the visual results are encouraging as well.

I plan to step down to a once or twice a week fast once I reach my goal just to maintain good health for the long term. Hopefully it all pans out!

Good results for a short time period!

Another benefit of IF for me which I thought of today. I am unsure if I will be able to fit in my workout this arvo because of various other stuff going on. Coming up to the time that I would be working out, I will have taken in 1100cals for the day. If I can workout, then I get to feast on pretty much whatever to get an additional 80g protein minimum and about 1500cals. If I don't workout, then I still aim for my 80g of protein but 1000 cals max (hence a "cleaner" food choice would be required)

Things like this make it good and flexible for me.

mormas

Hi,

I'm interested in IF and have subconsiously done it for years by not eating breakfast. There is so much info on the net that I am a bit mind boggled, and was wondering if someone could look at my plan (below) to see if I got my head around it, and offer any tips.

My goal is weight / fat loss at this point, but I will be looking to add more strength training soon.

My plan is to complete 16/8 (eating window between noon and 8pm) five days a week
Am I correct in thinking during this 'eating window' I eat the calories allocated to me via MFP
I complete Cardio for about an hour a day, which I normally compete either just before my eating window opens, or about 4pm, so I should be able to eat following my workout.

Any advise appreciated

Huskeryogi

My plan is to complete 16/8 (eating window between noon and 8pm) five days a week
Am I correct in thinking during this 'eating window' I eat the calories allocated to me via MFP
I complete Cardio for about an hour a day, which I normally compete either just before my eating window opens, or about 4pm, so I should be able to eat following my workout.

Any advise appreciated

Sounds like a very similiar plan to what I do. I only do cardio 5 days/week and I stick to my eating window even on weekends unless there's an event (I had brunch with my family on Sunday).

But I do stick to the calories allocated by MFP. The only difference for me is that I look at calorie intake from a weekly basis. Daily MFP allocates 1550 cal/daily w/o exercise. If I know I have something fun/food oriented coming up on Saturday, on Wednesday and Thursday I might only eat 1200 calories. That usually puts me 800 calories under my MFP goal for those days so I have some room to play with on Saturday.

I mostly do my cardio around 5:30 when I get home from work. I would prefer to do it in the morning in a fasted state, but I haven't been able to get myself up to do that yet.

pork_belly

I normally don't weigh in until Friday but I decided to take a look just in case I need to make adjustments. I was pleasantly surprised to find that in 5 days I've lost 3 lbs. I haven't felt starving and other than my first day I didn't feel like I ate a lot more than I normally do. In fact, I now am eating less than when I wasn't on IF. Not only did I lose 3 lbs but I also went down one percent in bodyfat. Looking forward to my official weigh in on Friday.

chrisdavey

To reiterate, if you are planning on doing IF LG style, one of the main contributing factors is resistance training and lifting heavy. You intake more cals on this day than you do on your rest days. Or conversely, you could intake similar calories and create your deficit through your cardio exercise on this day.

e.g.
Mon: train 2000cals exercise cals -200 net 1800
Tue: 1400cals gross and no exercise or 2000cals gross and -600 from cardio to net 1400. (high intensity cardio will impact recovery so be aware of this)

http://www.leangains.com/2008/06/sure-fire-fat-loss.html

stroken96

So this IF is fasting when and how?

chrisdavey

So this IF is fasting when and how?

did you read anything?

theresamommyof4

Okay, I'm just now getting started on IF. I haven't bought the books, I've just read the research, and I'm ready to kick it into high gear... but I have some questions. I'll tell you guys what I'm doing, and you tell me where I'm going wrong.

I decided to do the 24 hours on, 24 hours off. I start my fast at about 1:30pm and fast until the following day at 1:30 pm. Then eat from 1:30pm until about 8:00 at night, then wake up and eat until 1:30 and start my fast again. My question is this.... should I treat that "feeding"period as 1 day and eat only my 1500 calories, spread out between that afternoon, evening and next morning), or should I try to cram in those calories (the full 1500) that afternoon and evening, and then cram them in again the next morning for a total of 3,000 calories during my eating hours?

My mind is so programed to be TERRIFIED of starvation mode, that I feel like I need to get in those calories, but seriously there's not a snowballs chance that I can eat that much comfortably.

The first day I started the fast (Saturday), I ate oatmeal with peanut butter and blueberries for beakfast, then ate a veggie burger on a whole wheat sandwhich thin and a grapefruit for lunch (a little over 600 calories) Started my fast at 1:30. Fasted 24 hours with some cardio thrown in and drank lots of water. Sunday at 1:30pm, I broke my fast with a cup of whole wheat pasta, a couple of sauteed chicken tenders and sauteed zucchini (with olive oil), then ate snacks and a low carb dinner for a total of 1200 calories. Then this morning, I woke up, ate my normal oatmeal with peanut butter and berries, had snacks and ate another veggie burger for lunch for a total of 1,006 calories today. So in a 24 hour period, I've eaten over 2200 calories, and I could have done less because I was FULL before I started my fast... uncomfortably so.

I started my second 24 hour fast today at 1:30 and I'll end the fast at 1:30 pm tomorrow.

So am I eating enough calories? Do I need to eat less or more? Are 24 hour fasts, 3 or 4 x's a week too much, or it that a healthy goal?

Thanks in advance for the help!

CALIECAT

Bump

pork_belly

I'm doing the Fast-5 fast with low-carb (a la Atkins) for feeding.

Alloranx

Hi theresamommyof4,

I am kind of new to this myself, but I'll try to answer your questions, and others can correct me if I'm running off the rails:

My question is this.... should I treat that "feeding"period as 1 day and eat only my 1500 calories, spread out between that afternoon, evening and next morning), or should I try to cram in those calories (the full 1500) that afternoon and evening, and then cram them in again the next morning for a total of 3,000 calories during my eating hours?

Based on what Brad Pilon says in Eat Stop Eat, it seems to me that you can do pretty much whatever on feeding days as long as you aren't binging on a bunch of crappy food. The way he puts it is----just forget that your fast happened after you get off of it, and eat normally. Don't try to make up for the fast by gorging yourself, just eat like you would if you hadn't fasted at all. I've been taking that advice, and had good results. I don't worry that much about what I eat on my feeding days, I just don't go crazy. According to him, that is the power of the Intermittent Fasting method in general: it's very flexible. You can do any kind of "mainstream" weight loss diet you want on the feeding days, or you can just let the fasting do its work and eat a non-restrictive diet, which is what I'm doing (within reason, of course).

My mind is so programed to be TERRIFIED of starvation mode, that I feel like I need to get in those calories, but seriously there's not a snowballs chance that I can eat that much comfortably.

Again, based on what Brad says, starvation mode is largely overblown. The idea that your metabolism slows down hugely without sufficient calories does not seem to be based in fact. He presents a lot of research that suggests that your basal metabolism is rooted almost exclusively in your lean body mass. You can (slightly) increase your metabolism with exercise and (somewhat more) by putting on muscle long-term, but food has little to do with it. He has one nice graph (which unfortunately he doesn't source) which shows basal metabolic rates for people with different lean body masses on different diets. Diet has pretty much no effect. It's a direct relationship - more lean body mass equals more basal metabolism, regardless of diet (even with very low calorie diets).

What I take away from all this is: in order to enter "starvation mode", you have to have very little fat left so that your body starts significantly catabolizing muscle, and then as your lean mass goes down, your metabolism will go down. Our bodies desperately try to preserve protein in muscle until the last possible minute, because, though it can be burned, it's structural. It's needed for you to survive, and ideally, to find more food. The majority of fat that most people have is storage fat whose primary function is to be an energy reserve. To burn the protein while you still have fat left to burn would be like someone trying to get warm during the winter by busting up furniture and rafters to put in the fireplace when they still have a pile of perfectly good firewood standing by. So your body is going to try to get rid of all the fat before dipping into muscle and lowering your metabolism.

Thus far in my 3 week experience with doing alternate day fasting like you, I have not seen any lean mass loss, and if anything my strength has continued to go up even though I am not doing anything terribly time consuming, exercise-wise.

So am I eating enough calories? Do I need to eat less or more? Are 24 hour fasts, 3 or 4 x's a week too much, or it that a healthy goal?

Any advice you get on that will probably be opinion. As for me, I do not devote even a second to worrying about starvation mode. Unless you're at super-athlete body fat level, you probably shouldn't either. I'd say just listen to your body: if you can eat fewer calories without feeling tired or hungry, then go for it, as long as you're eating nutritious foods. As for whether it is healthy....that's harder to say, but studies in rats suggest that every other day fasting is very healthful, and I suspect it is the same in humans (there have been a couple of studies to that effect). I've felt great doing it, honestly. Food tastes so much better after fasting!

theresamommyof4

Hi theresamommyof4,

I am kind of new to this myself, but I'll try to answer your questions, and others can correct me if I'm running off the rails:

My question is this.... should I treat that "feeding"period as 1 day and eat only my 1500 calories, spread out between that afternoon, evening and next morning), or should I try to cram in those calories (the full 1500) that afternoon and evening, and then cram them in again the next morning for a total of 3,000 calories during my eating hours?

Based on what Brad Pilon says in Eat Stop Eat, it seems to me that you can do pretty much whatever on feeding days as long as you aren't binging on a bunch of crappy food. The way he puts it is----just forget that your fast happened after you get off of it, and eat normally. Don't try to make up for the fast by gorging yourself, just eat like you would if you hadn't fasted at all. I've been taking that advice, and had good results. I don't worry that much about what I eat on my feeding days, I just don't go crazy. According to him, that is the power of the Intermittent Fasting method in general: it's very flexible. You can do any kind of "mainstream" weight loss diet you want on the feeding days, or you can just let the fasting do its work and eat a non-restrictive diet, which is what I'm doing (within reason, of course).

My mind is so programed to be TERRIFIED of starvation mode, that I feel like I need to get in those calories, but seriously there's not a snowballs chance that I can eat that much comfortably.

Again, based on what Brad says, starvation mode is largely overblown. The idea that your metabolism slows down hugely without sufficient calories does not seem to be based in fact. He presents a lot of research that suggests that your basal metabolism is rooted almost exclusively in your lean body mass. You can (slightly) increase your metabolism with exercise and (somewhat more) by putting on muscle long-term, but food has little to do with it. He has one nice graph (which unfortunately he doesn't source) which shows basal metabolic rates for people with different lean body masses on different diets. Diet has pretty much no effect. It's a direct relationship - more lean body mass equals more basal metabolism, regardless of diet (even with very low calorie diets).

What I take away from all this is: in order to enter "starvation mode", you have to have very little fat left so that your body starts significantly catabolizing muscle, and then as your lean mass goes down, your metabolism will go down. Our bodies desperately try to preserve protein in muscle until the last possible minute, because, though it can be burned, it's structural. It's needed for you to survive, and ideally, to find more food. The majority of fat that most people have is storage fat whose primary function is to be an energy reserve. To burn the protein while you still have fat left to burn would be like someone trying to get warm during the winter by busting up furniture and rafters to put in the fireplace when they still have a pile of perfectly good firewood standing by. So your body is going to try to get rid of all the fat before dipping into muscle and lowering your metabolism.

Thus far in my 3 week experience with doing alternate day fasting like you, I have not seen any lean mass loss, and if anything my strength has continued to go up even though I am not doing anything terribly time consuming, exercise-wise.

So am I eating enough calories? Do I need to eat less or more? Are 24 hour fasts, 3 or 4 x's a week too much, or it that a healthy goal?

Any advice you get on that will probably be opinion. As for me, I do not devote even a second to worrying about starvation mode. Unless you're at super-athlete body fat level, you probably shouldn't either. I'd say just listen to your body: if you can eat fewer calories without feeling tired or hungry, then go for it, as long as you're eating nutritious foods. As for whether it is healthy....that's harder to say, but studies in rats suggest that every other day fasting is very healthful, and I suspect it is the same in humans (there have been a couple of studies to that effect). I've felt great doing it, honestly. Food tastes so much better after fasting!

Wow... thanks. That was exactly what I needed to know! I really appreciate all of the time you put into that, it helped temendously! ~Theresa

mormas

Well I stopped eating last night at 2000hrs and have fasted until 1215hrs this afternoon, and to be honest it wasn't as difficult as I imagined it would be. It is way to early to decide if this is going to be a new way of eating for me, but I am going to give it a go for a while and have started a blog where I will be posting how I'm getting on and my results, and my plan of action. Please feel free to have a look and offer any advice. Please remember I am new to this and may have got things wrong or muddled up, but I can adapt tofind a way to work, hence the blog being called an experiment in Intermittent fasting. I attach the link below.

http://www.myfitnesspal.com/blog/mormas/view/intermittent-fasting-an-experiment-beginning-26-07-11-129075

joejccva71

I not only do Intermittent Fasting but I incorporate Carb Cycling into it as well at the same time.

I fast 16 hours a day from the hours of 8pm to 12 noon the next day, then I have an 8 hour feeding window.

Works like a charm. I also train in the morning so it's on an empty stomach.

chrisdavey

Smashed over 1100 cals of healthy foods post workout yesterday! Love IF

pork_belly

I not only do Intermittent Fasting but I incorporate Carb Cycling into it as well at the same time.

I fast 16 hours a day from the hours of 8pm to 12 noon the next day, then I have an 8 hour feeding window.

Works like a charm. I also train in the morning so it's on an empty stomach.

I do similar but I don't know if its called carb cycling. I just reduce my carbs to under 100 but am typically down in the 20-30s. I follow the Fast-5 fasting schedule with only a 5 hour feeding window. 5PM-10PM.

Setapart

I took a day off, and boy did it throw me for a loop! I went carb crazy. I'm going to look into getting back on track with decreasing my carbohydrates, rather than trying to do IF right now. However, I do like the practice of not eating after 6:30 except for special occasions if I can swing it. I could feasibly be happy with a 10 hour feeding window.

hush7hush

Preparing for a 24+ hour fast tomorrow. [:

rileysowner

Just coming off a 32 hour fast. Feeling great.

Teemo

Our bodies desperately try to preserve protein in muscle until the last possible minute, because, though it can be burned, it's structural. It's needed for you to survive, and ideally, to find more food. The majority of fat that most people have is storage fat whose primary function is to be an energy reserve. To burn the protein while you still have fat left to burn would be like someone trying to get warm during the winter by busting up furniture and rafters to put in the fireplace when they still have a pile of perfectly good firewood standing by. So your body is going to try to get rid of all the fat before dipping into muscle and lowering your metabolism.

The opposite, actually.

Glycogen from the muscles is catabolized first, followed by protein from lean tissue, then fat. It's why doing cardio on an empty stomach (long held to be the "best" way to lose fat) is counterproductive if your goal is to preserve lean mass.

Teemo

*double post*

MFP should really let you delete posts.

rileysowner

Our bodies desperately try to preserve protein in muscle until the last possible minute, because, though it can be burned, it's structural. It's needed for you to survive, and ideally, to find more food. The majority of fat that most people have is storage fat whose primary function is to be an energy reserve. To burn the protein while you still have fat left to burn would be like someone trying to get warm during the winter by busting up furniture and rafters to put in the fireplace when they still have a pile of perfectly good firewood standing by. So your body is going to try to get rid of all the fat before dipping into muscle and lowering your metabolism.

The opposite, actually.

Glycogen from the muscles is catabolized first, followed by protein from lean tissue, then fat. It's why doing cardio on an empty stomach (long held to be the "best" way to lose fat) is counterproductive if your goal is to preserve lean mass.

While I agree on the glycogen, I am not sure it is as simple as you seem to indicate about going to lean tissue for energy before fat. At least in the first 36-72 hours of a fast your body burns more fat for energy. That does change as the fasted state continues, but to immediately catabolize lean tissue when in a fasted state would be counter-productive for survival as the lean tissue is needed to hunt down or find the next meal. I would like to see some references to the process either way.

Teemo

While I agree on the glycogen, I am not sure it is as simple as you seem to indicate about going to lean tissue for energy before fat. At least in the first 36-72 hours of a fast your body burns more fat for energy. That does change as the fasted state continues, but to immediately catabolize lean tissue when in a fasted state would be counter-productive for survival as the lean tissue is needed to hunt down or find the next meal. I would like to see some references to the process either way.

I am not sure what you want a reference to. That protein in lean tissue will be broken down for amino acids (which cannot be obtained from adipose tissue)? Or that lean tissue will be broken down first in the absence of dietary calories? (Compare relative energy cost of breaking down proteins vs. breaking down fats.)

Though really, for purposes, of this argument both lean and adipose tissue are being broken down more or less simultaneously... and in a 24 hour fast, neither is really being done to any significant extent. However, I don't believe your statement that your body will try to preserve protein in your muscles until the last possible minute is correct; especially if your body has no other source for protein.

rileysowner

While I agree on the glycogen, I am not sure it is as simple as you seem to indicate about going to lean tissue for energy before fat. At least in the first 36-72 hours of a fast your body burns more fat for energy. That does change as the fasted state continues, but to immediately catabolize lean tissue when in a fasted state would be counter-productive for survival as the lean tissue is needed to hunt down or find the next meal. I would like to see some references to the process either way.

I am not sure what you want a reference to. That protein in lean tissue will be broken down for amino acids (which cannot be obtained from adipose tissue)? Or that lean tissue will be broken down first in the absence of dietary calories? (Compare relative energy cost of breaking down proteins vs. breaking down fats.)

Though really, for purposes, of this argument both lean and adipose tissue are being broken down more or less simultaneously... and in a 24 hour fast, neither is really being done to any significant extent. However, I don't believe your statement that your body will try to preserve protein in your muscles until the last possible minute is correct; especially if your body has no other source for protein.

I don't think the original quote was mine, but a quick look through the thread and I couldn't find it so I don't know. I would agree that is an overstatement, but at the same time if the body immediately jumped to protein for an energy source as opposed to scavenging amino acids it would be a less than helpful survival process as muscle is needed to hunt food and in times of intermittent shortage eating what is needed to procure those things needed for survival would be less than helpful.

crisanderson27

I didn't have the time to read all 10 pages...but I have been practicing Eat, Stop, Eat for a couple weeks now.

See, I was on a 6 week plateau, at 189-192lbs. Nothing was working...not eating clean, not zig zagging, not upping or lowering calories...nothing. Then, I got sick...and I mean, violently sick for two days. I didn't eat...at all, anything I ate would just come back up. On the third day I was ravenous...and since we were out of groceries...we ate Taco Bell. I'd started working again...tons of hours, and it was a couple weeks before I got back to the grocery store to pick up real food. It was also two full weeks before I began exercising again. I started a cycle of two days very low calorie (with large spacing between meals), and one day above maintenance.

During that two weeks, I lost 8lbs, and 4" or so on my waist. I gained 1/4" on my biceps.

I so totally didn't understand, and no one could explain it. It went against everything I'd learned on this site and others. Then it was recommended to me by my bodyweight workout mentor to look into Eat Stop Eat...that he used it and that it was working well for him. I did. It totally explained what had happened to me during those two weeks. So now I'm doing it on purpose. I do have to say, I'm not eating as clean as I'd like...and I think that's starting to impact my gains...but in the first three weeks (including the two without exercise), I lost 12lbs and over 5" on my waist. All of this VERY near my goal weight as well.

Currently, I'm trying to work out a way to eat more cleanly with my work schedule, along with eating more normally on Eat days. It shouldn't be hard to pick back up...but it might take a little time. I think once I'm on that path...the gains will come quickly again.

Anyhow...there it is, my experience with IF =D.

chrisdavey

^^^^ champion effort mate. Keep it up

Just saw this girl posting on Martin's FB page. Said she follow LG principles exactly nutritionally but preferred to do higher reps for weights. Looks pretty bloody amazing. No before shots unfortunately.

http://www.facebook.com/photo.php?fbid=10150737855370473&set=a.10150677047500473.711279.606740472&type=1&ref=nf

Alloranx

The opposite, actually.

Glycogen from the muscles is catabolized first, followed by protein from lean tissue, then fat. It's why doing cardio on an empty stomach (long held to be the "best" way to lose fat) is counterproductive if your goal is to preserve lean mass.

That's broscience, I'm afraid. Fat is an energy storage molecule. It contains more than double the energy of protein pound for pound, and has relatively few crucial functions outside of energy production in our bodies when compared with the myriad critical functions of protein. It makes no sense whatsoever for our bodies to break down protein first, which is, as I said, structural and necessary for survival, when fat is lying around just waiting to be burned. That is, in fact, what usually kills people people who are starving: arrhythmia due to breakdown of proteins in the heart, or respiratory failure due to breakdown of the diaphragm. Obviously the body avoids that as long as possible. It's late and I'm not going to go finding a bunch of sources for you right now, but even the lowly Wikipedia disagrees with you:

http://en.wikipedia.org/wiki/Starvation_response
http://en.wikipedia.org/wiki/Fasting#Health_effects

If you want to convince me that proteins are broken down first, I need to see at least *some* sources. I'm not just going to take your word for it. I just did a quick Google search and literally every source I found said that fat is burned burned before proteins during fasting until only essential fat remains (~4-5% body fat for males, basically super-athlete / cut bodybuilder level).

I am not sure what you want a reference to. That protein in lean tissue will be broken down for amino acids (which cannot be obtained from adipose tissue)?

The requirement for amino acids as an energy source during fasting is minimal while fat is still present, as stated in the article on starvation I posted above. There is of course some turnover of proteins during fasting, but that's not much different from the non-fasting state.

Or that lean tissue will be broken down first in the absence of dietary calories? (Compare relative energy cost of breaking down proteins vs. breaking down fats.)

I spent a few minutes looking on Google Scholar and found no easily comparable values for these two things. Have a handy source? In any case, I *highly* doubt that the energy cost vs. energy production on breaking down proteins is favorable compared to fats. Amino acids are in general tied up in complex structures like enzymes, membrane channels, extracellular matrix, cell skeletons, muscle fibers, and so on (all of which cost a lot of energy to create, and a lot of energy to break down, and don't give a very good ATP return). Fats are mostly just sitting around in globs within adipocytes waiting to be burned. That is their function - energy storage (as well as some minor other functions like body temperature buffering and shock absorption). Why would our bodies save fat (a high energy, accessible molecule) for last and instead cripple us by destroying muscle? It makes no sense.

Though really, for purposes, of this argument both lean and adipose tissue are being broken down more or less simultaneously... and in a 24 hour fast, neither is really being done to any significant extent.

I agree, they are being broken down simultaneously. Then again, they're always being broken down simultaneously, even in the fed state, though to a much lesser degree. The question is which is being broken down to a greater extent, and what counts as "significant" in your view? Anecdotally at least, I count the fat breakdown as significant...I've lost about 4% body fat over the past 3 weeks doing IF, and by my calculations my lean mass has stayed almost exactly the same...on top of that I have essentially not restricted my diet at all on my feeding days: I'm just eating like I was when I didn't give a crap about losing weight. And I'm still losing a ton of fat and actually gaining strength at the same time. Interesting, no?

However, I don't believe your statement that your body will try to preserve protein in your muscles until the last possible minute is correct; especially if your body has no other source for protein.

Your error is in thinking that the body has a large need for amino acids themselves in a fasting state: it doesn't. There is a constant process of breaking down old proteins and recreating new ones from the breakdown products going on all the time that doesn't necessarily need a large influx of new exogenous amino acids. The major concern of your body in a fasting state, though, is not anabolism, that is, building new cells, enzymes, and muscles and such. It is catabolism - breaking things down to keep what you already have alive and running. Relatively few amino acids are required for this. What's needed is ATP, that is, energy, which is provided more efficiently from fat.

I will spend some time hunting down studies to back up what I've said in the near future. In any case, I recommend to you Brad Pilon's book Eat Stop Eat. He makes extensive citations to the research literature to back up the idea that for most people who are not already super-low body fat, short-term fasting does not cause a large increase in muscle catabolism, and it does cause a large increase in fat catabolism.

rileysowner

The opposite, actually.

Glycogen from the muscles is catabolized first, followed by protein from lean tissue, then fat. It's why doing cardio on an empty stomach (long held to be the "best" way to lose fat) is counterproductive if your goal is to preserve lean mass.

That's broscience, I'm afraid. Fat is an energy storage molecule. It contains more than double the energy of protein pound for pound, and has relatively few crucial functions outside of energy production in our bodies when compared with the myriad critical functions of protein. It makes no sense whatsoever for our bodies to break down protein first, which is, as I said, structural and necessary for survival, when fat is lying around just waiting to be burned. That is, in fact, what usually kills people people who are starving: arrhythmia due to breakdown of proteins in the heart, or respiratory failure due to breakdown of the diaphragm. Obviously the body avoids that as long as possible. It's late and I'm not going to go finding a bunch of sources for you right now, but even the lowly Wikipedia disagrees with you:

http://en.wikipedia.org/wiki/Starvation_response
http://en.wikipedia.org/wiki/Fasting#Health_effects

If you want to convince me that proteins are broken down first, I need to see at least *some* sources. I'm not just going to take your word for it. I just did a quick Google search and literally every source I found said that fat is burned burned before proteins during fasting until only essential fat remains (~4-5% body fat for males, basically super-athlete / cut bodybuilder level).

I am not sure what you want a reference to. That protein in lean tissue will be broken down for amino acids (which cannot be obtained from adipose tissue)?

The requirement for amino acids as an energy source during fasting is minimal while fat is still present, as stated in the article on starvation I posted above. There is of course some turnover of proteins during fasting, but that's not much different from the non-fasting state.

Or that lean tissue will be broken down first in the absence of dietary calories? (Compare relative energy cost of breaking down proteins vs. breaking down fats.)

I spent a few minutes looking on Google Scholar and found no easily comparable values for these two things. Have a handy source? In any case, I *highly* doubt that the energy cost vs. energy production on breaking down proteins is favorable compared to fats. Amino acids are in general tied up in complex structures like enzymes, membrane channels, extracellular matrix, cell skeletons, muscle fibers, and so on (all of which cost a lot of energy to create, and a lot of energy to break down, and don't give a very good ATP return). Fats are mostly just sitting around in globs within adipocytes waiting to be burned. That is their function - energy storage (as well as some minor other functions like body temperature buffering and shock absorption). Why would our bodies save fat (a high energy, accessible molecule) for last and instead cripple us by destroying muscle? It makes no sense.

Though really, for purposes, of this argument both lean and adipose tissue are being broken down more or less simultaneously... and in a 24 hour fast, neither is really being done to any significant extent.

I agree, they are being broken down simultaneously. Then again, they're always being broken down simultaneously, even in the fed state, though to a much lesser degree. The question is which is being broken down to a greater extent, and what counts as "significant" in your view? Anecdotally at least, I count the fat breakdown as significant...I've lost about 4% body fat over the past 3 weeks doing IF, and by my calculations my lean mass has stayed almost exactly the same...on top of that I have essentially not restricted my diet at all on my feeding days: I'm just eating like I was when I didn't give a crap about losing weight. And I'm still losing a ton of fat and actually gaining strength at the same time. Interesting, no?

However, I don't believe your statement that your body will try to preserve protein in your muscles until the last possible minute is correct; especially if your body has no other source for protein.

Your error is in thinking that the body has a large need for amino acids themselves in a fasting state: it doesn't. There is a constant process of breaking down old proteins and recreating new ones from the breakdown products going on all the time that doesn't necessarily need a large influx of new exogenous amino acids. The major concern of your body in a fasting state, though, is not anabolism, that is, building new cells, enzymes, and muscles and such. It is catabolism - breaking things down to keep what you already have alive and running. Relatively few amino acids are required for this. What's needed is ATP, that is, energy, which is provided more efficiently from fat.

I will spend some time hunting down studies to back up what I've said in the near future. In any case, I recommend to you Brad Pilon's book Eat Stop Eat. He makes extensive citations to the research literature to back up the idea that for most people who are not already super-low body fat, short-term fasting does not cause a large increase in muscle catabolism, and it does cause a large increase in fat catabolism.

This is the response I would have liked to write, good response.

Teemo

Obviously the body avoids that as long as possible. It's late and I'm not going to go finding a bunch of sources for you right now, but even the lowly Wikipedia disagrees with you:

http://en.wikipedia.org/wiki/Starvation_response

For the sake of this discussion, these are the sources which the Wikipedia article cites to:

http://www.weightlossresources.co.uk/calories/burning_calories/starvation.htm
"The main way it does this is to protect its fat stores and instead use lean tissue or muscle to provide it with some of the calories it needs to keep functioning."

http://www.healthpromoting.com/Articles/articles/therap.htm
"Fortunately, this is not a problem. In fact, within ten hours from the last meal approximately 50% of muscle fuel is coming from fat. Even the brain itself begins to shift over the fat metabolism. The consumption of protein reserves decreases from 75 grams per day at the beginning of a fast to just 20 grams a day by the end of the second week."

http://www.netwellness.org/question.cfm/37350.htm
"Once fat stores are exhausted though, protein is used, leading to death once all protein stores are utilized"

Please note that I am not claiming that any of these are authoritative sources and, especially in the context of the "Ask a Dietitian, etc." articles, I'm almost inclined to consider them the opposite.

If you want to convince me that proteins are broken down first, I need to see at least *some* sources. I'm not just going to take your word for it. I just did a quick Google search and literally every source I found said that fat is burned burned before proteins during fasting until only essential fat remains (~4-5% body fat for males, basically super-athlete / cut bodybuilder level).

I'll retract my statement, though I would appreciate a link to the source saying that fat is burned during fasting until only essential fat remains, before muscle is catabolized. If that's true, you may have just hit upon the easiest way to get ripped ever and revolutionized the contest-dieting procedure.

I agree, they are being broken down simultaneously. Then again, they're always being broken down simultaneously, even in the fed state, though to a much lesser degree. The question is which is being broken down to a greater extent, and what counts as "significant" in your view? Anecdotally at least, I count the fat breakdown as significant...I've lost about 4% body fat over the past 3 weeks doing IF, and by my calculations my lean mass has stayed almost exactly the same...on top of that I have essentially not restricted my diet at all on my feeding days: I'm just eating like I was when I didn't give a crap about losing weight. And I'm still losing a ton of fat and actually gaining strength at the same time. Interesting, no?

Not really interesting. Strength gains are not dependent on lean mass preservation or lean mass gains. It's entirely possible to increase in strength while losing lean mass. Again, if you have a source for the argument that fasting is muscle sparing absent the ingestion of protein I'd love to read it. Would save me a fortune on protein. (Non-sarcastic).

I will spend some time hunting down studies to back up what I've said in the near future.

Appreciated!

In any case, I recommend to you Brad Pilon's book Eat Stop Eat. He makes extensive citations to the research literature to back up the idea that for most people who are not already super-low body fat, short-term fasting does not cause a large increase in muscle catabolism, and it does cause a large increase in fat catabolism.

ESE, if I recall, recommends a high intake of protein even during dieting/fasting.

Teemo

I don't think the original quote was mine, but a quick look through the thread and I couldn't find it so I don't know. I would agree that is an overstatement, but at the same time if the body immediately jumped to protein for an energy source as opposed to scavenging amino acids it would be a less than helpful survival process as muscle is needed to hunt food and in times of intermittent shortage eating what is needed to procure those things needed for survival would be less than helpful.

I think my disagreement, and your very common sense consideration, are both taken care of if you distinguish between the catabolization RATIO of protein/fats vs. the catabolization ORDER of proteins/fats.

Note that I am not saying that lean muscle is exclusively catabolized first, only that:

1) the statement that fat stores are catabolized COMPLETELY before lean tissue is incorrect.
2) the statement that fat stores are catabolized FIRST before lean tissue is incorrect.

Again, your common sense response is easily taken into regard then. Lean tissue is catabolized first, fat stores second (though more or less simultaneously) and a greater percentage of fat stores are catabolized vs. lean tissue. Right?