Intermittent Fasting Support Group?

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!

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.

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.

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.

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.

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.

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.