Zero carb diet destroys fat cells...in rats

[Viking Dan]

If I'm reading this correctly. Sadly, I can only get at the abstract.

http://jn.nutrition.org/cgi/content/abstract/136/5/1256


Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

A High-Protein, High-Fat, Carbohydrate-Free Diet Reduces Energy Intake, Hepatic Lipogenesis, and Adiposity in Rats

Lisa Pichon, Jean-François Huneau, Gilles Fromentin1 and Daniel Tomé
UMR INRA 914 Physiologie de la Nutrition et du Comportement Alimentaire, Institut National Agronomique Paris-Grignon, F75231 PARIS Cedex 05, France


1 To whom correspondence should be addressed. E-mail: fromenti@inapg.fr.
The aim of this work was to determine the effects in rats of ingesting 1 of 3 diets with normal or high protein concentrations and various carbohydrate:lipid ratios on weight gain, body composition, and the development and metabolism of white adipose tissue (WAT). For this purpose, male Wistar rats were fed for 20 or 42 d a high-carbohydrate, low-fat, normal-protein diet (76, 10, and 14% of energy as carbohydrate, lipid, and protein, respectively, carbohydrate:lipid ratio (C/L) = 7.6), a normal-carbohydrate, low-fat, high-protein diet (35, 10, and 55% of energy as carbohydrate, lipid, and protein respectively, C:L = 3.5), or a carbohydrate-free, high-fat, high-protein diet (45 and 55% of energy as fat and protein, respectively, C:L = 0). Growth, food intake, body composition, WAT cellularity, and several markers of lipogenesis including fatty acid synthase and lipoprotein lipase activities were measured in adipose tissue and liver. Lowering the C:L ratio reduced the development of WAT, weight gain, body fat mass, and adipocyte size, and in rats fed the carbohydrate-free diet (C:L = 0), the total number of adipocytes in subcutaneous WAT. These reductions in adipose tissue development with decreases in the C:L ratio of the diet seemed to be due primarily to reduced hepatic lipogenesis.

[Gabriel Guzman]

If I'm reading this correctly...


I'm afraid you are... It doesn't say that the cells are distroyed. What it says that the rats' adiposity was reduced, specifically white addipose tissue (WAT).

Adipogenesis comprises two process, enlargment of pre-existing cells and development of new cells. The issue is still debated when we talk about humans; some people maintain that once a certain treshold in the number of adipose cells is reched, then there can't be more new cells. Some others maintain that, given the appropriate stimuli, there is always new adipocytes developing. There is evidence for both.

What that abstract suggest is that when carbohydrates are reduced, but still present, there is a decrease in the adipose mass due to decrease in size of the cells, and decrease in lipogenesis. Hard to see what happens when carbohydrates are not present at all... That particular sentence in the abstract is not complete (not very good if I was a reviewer of that paper). Nonetheless, it seems to suggest that hepathic lipogenesis is the cause behind the reduction in the number of WAT cells. If anything, this is a good thing as it was the amount of carbohydrate what caused that, not the amount of lipid.

Of course, we need to read the piece to see the details (when I get it), but from the abstract, which is suppose to be the 'catchy' part of the article, the conslusion doesn't mention protein at all, only the ratio carbohydrate:lipid. Fat content was left unchanged in the diets that had carbohydrate. Protein content, on the other hand, changed from 14% to 55% and that is an important detal. Thus, the ratio that is important to mention is the ratio C:P instead of C:F. If that is consider, then the conclusion is even more interesting (then again it isn't....) because a decrease in carbohydrate with an increase in protein resulted in less adipose mass.

Removing carbohydrate from the diet and just feeding fat and protein, of course, doesn't provide much in terms of hormonal control for fat synthesis, so from that point of view is not surprising that in the absence of carbohdyrate there is a reduction in the total number of adipocytes (i.e. adipose mass). A priori, another way to interpret this is that increasing the amount of at from 10 to 45% in the absence of carbohydrate didn't make these rats fats.

Donald Layman has reported similar results in humans. In his studies, he changd the ratio C:P and the study subjects (women) not only did not gain weight but acquired better postprandial normoinsulinemia and normoglycemia. When I get my hands on the complete article, we'll see what else is new, if anything.

[Viking Dan]

I'm afraid you are... It doesn't say that the cells are distroyed. What it says that the rats' adiposity was reduced, specifically white addipose tissue (WAT).

I'm sure I am. But how does "and in rats fed the carbohydrate-free diet (C:L = 0), the total number of adipocytes in subcutaneous WAT." not mean getting rid of fat cells? Adipocytes are fat cells, no? And they seem to stress this effect only in the zero carb diet. It says the total number of them decreased.

Not arguing. Just want a better sense of what I'm (mis)reading here.

[Viking Dan]

How about this?

http://www.redorbit.com/news/health/112004/increasing_the_protein_content_in_a_carbohydratefr ee_diet_enhances_fat/

Increasing the Protein Content in a Carbohydrate-Free Diet Enhances Fat Loss During 35% but Not 75% Energy Restriction in Rats

ABSTRACT
The purpose of the present study was to test the influence of the amount of protein in a carbohydrate-free diet during a weight reducing program using severe (75%) or more moderate (35%) energy restriction in rats. In Expt. 1, 3 groups (n = 6) consumed ad libitum a high-carbohydrate, low-fat diet [P21C69L10 containing 21% of energy as protein (P21), 69% carbohydrate (C69) and 10% lipids (L10)], a high-carbohydrate, high-fat diet (P21C34L45), or a carbohydrate-free, high-fat, high-protein diet (P55L45). In Expt. 2, 7 groups (n = 7) were studied. For 20 d, groups 1-4 consumed ad libitum diets containing macronutrients at the proportions indicated in their designations [P14C56L30 (control diet), P30L70, P50L50, and P90L10]. Groups 5-7 were pair-fed the same diets at the level of the spontaneous intake of the P90L10 group on the previous day (35% energy restriction). In Expt. 3, 5 groups (n = 7) were fed 1 of the following diets for 20 d. Group 1 consumed the control diet (P14C56L30) ad libitum. Groups 2-5 were energy restricted to 25% of the daily energy intake of group 1 with diets varying in their protein and lipid concentrations (P14C56L30, P50L50, P70L30, and P90L10). A high-fat content in the diet devoid of carbohydrate did not increase energy intake and body adiposity and neither body weight nor body composition was significantly affected by the protein to lipid ratio when energy restriction was 75%; however, a protein content > 50% preserved lean body mass at the expense of fat mass when energy restriction was 35%. Our results show that the absence of carbohydrates from the diet induces a low energy intake and the preferential deposition of protein. J. Nutr. 134: 2646- 2652, 2004.

[Gabriel Guzman]

I'm sure I am. But how does "and in rats fed the carbohydrate-free diet (C:L = 0), the total number of adipocytes in subcutaneous WAT." not mean getting rid of fat cells? Adipocytes are fat cells, no? And they seem to stress this effect only in the zero carb diet. It says the total number of them decreased.

Not arguing. Just want a better sense of what I'm (mis)reading here.

I see what you mean now. When fat cells are depleted from their fat droplets, then there is little left. Basically the rest of the organelles. Destruction has a different connotation, at least in Biology. For example, a virus that invades a cell can literally destroy it. A fat cell that is depleted of its fat may or not disapear. I know, sometimes semantics is everything. The point of the abstract, nonetheless is that a reduction in carbohydrate inhibits the proliferation of fat cells (increase in number) as well as their size. In any case, destruction of all fat cells, if possible, is almost impossible. Some engineered mice which over produce an important uncoupling protein are virtually 'all-muscle' with very little fat, but there is still some left. Destruction of all fat cells is life threatening and some people suffering from 'lipodystrophia' are at high risk.

[Viking Dan]

It seems there was the same % protein in the normal carb and the zero carb diet. What I'm wondering is if there is an additional advantage in weight loss by dropping to zero carb(meat and water, I suppose,) which is what this seems to say.

[Billie]

No and the risk is greater that you will lose interest and you will never learn or relearn good eating habits. After all that is what got his here to begin with huh! Why live lift without some enjoyment, without antioxidants, fiber, the crunch of veggies or the sweets of fruit. I would stick with 30 or 40 ECCs and not go to the Intervention phase, even the Atkins people revised their thinking on that.

[Viking Dan]

What I'm curious to know is that where between 35% and 0% carbs does this fat-cell-nuking-sorry-if-that's-the-wrong-term-for-it-gabe happen?

[Gaelen]

Dan, although we all want to nuke our share of fat cells (okay, I'd prefer they just melt away...), maintaining a certain level of fat cells is actually healthy and vital to the human body functioning correctly, and if there's one thing I've learned, it's that making the fat cells disappear more quickly isn't necessarily more effective long term.

I think the Drs. Eades were pretty clear in everything they've written that there's very little science to support that going lower than 30g ECC produces more effective results in fat loss, overall health improvements, etc., and the points Billie makes about sustainability of extremely low carb intake diets are good ones that apply to many people. Can some people go zero carb (or what they think is zero carb) and stay there indefinitely? Sure. Can most people? Heck, most people can't follow ANY menu plan forever, so not so much. ;)

For me, 30g ECC is about 10% of intake...and I can't sustain it for very long...a month is the longest I've ever managed at that ECC intake level.
OTOH, 40-45g ECC is comfortable for me and it's where I spent most of my active weight loss period. That's about 12-15% of intake for me, depending on the day...and my bodyfat percentage reduced approximately 20% during that time (by measurement calculation, impedance testing and other forms of external fat percentage calculations like calipers.) It's also worth it to mention that the fat loss I experienced probably wouldn't have occurred to that degree without regular exercise. Right now, I can eat properly but my exercise is severely limited. I'm losing weight, and my lipid profile is fantastic, but I'm not making nearly as much headway with inches or fat loss.

Individual results are going to vary, and the only way to narrow down what percentage of ECC intake equals fat loss, for you, is something you have to figure out by keeping tabs on your body fat percentage in relationship to your diet and your activity level. I know that there are some pretty vocal low carbers who favor things like fat fasts and meat and egg diets with minimal vegetable/fruit intake, and I've read all their testimonials...but no one offers up much more than their personal anecdotes to demonstrate success. So cool, it works for them...but I know in advance that it wouldn't work long term for me, and anything I choose has to work long term.

Considering the zero-carb testimonies tend to be personal anecdotes from internet typing demons you've never met...well...'trust but verify' has some merit here. :) OTOH, the references about controlled carb nutrition that produced the Drs. Eadeses' recommendations for 30-40g ECC have a body of published references behind them. So, you pays your money and you takes your choice. For me, I'll hang my bet on the (reliably) published stuff until that's disproven. YMMV.

[Viking Dan]

Dan, although we all want to nuke our share of fat cells (okay, I'd prefer they just melt away...), maintaining a certain level of fat cells is actually healthy and vital to the human body functioning correctly, and if there's one thing I've learned, it's that making the fat cells disappear more quickly isn't necessarily more effective long term.

Yeah. I don't intend to be a skeleton. But if there is a sweeter spot for shedding fat, I'm willing to experiment.

Can some people go zero carb (or what they think is zero carb) and stay there indefinitely? Sure. Can most people? Heck, most people can't follow ANY menu plan forever, so not so much. ;)

As long as food isn't entertainment or some kind of security blanket, why couldn't one stick to meat and water?

For me, 30g ECC is about 10% of intake...and I can't sustain it for very long...a month is the longest I've ever managed at that ECC intake level. Individual results are going to vary, and the only way to narrow down what percentage of ECC intake equals fat loss, for you, is something you have to figure out by keeping tabs on your body fat percentage in relationship to your diet and your activity level.

<imho>
My belief is that calories are ultimately what determines weight loss. Low carb has a hunger blunting effect. That's its main advantage for weight loss. Its not like I wasn't able to lost weight on a low fat diet...I just wanted to murder people when I was on it. ;)
</imho>

I know that there are some pretty vocal low carbers who favor things like fat fasts and meat and egg diets with minimal vegetable/fruit intake, and I've read all their testimonials...but no one offers up much more than their personal anecdotes to demonstrate success.

The fat fast works because its 1000 calories/day. You'd have to be a mutant for that not to work.

As far as a no carb diet study, there's the Stefansson study at Bellvue. Hard to ignore that one, since almost every lc book I ever read cites it.

And Bear (http://thebear.org/essays1.html#anchor496162) (whose site was my first exposure to lc) has been doing zero carb for almost 50 years.

For me, I'll hang my bet on the (reliably) published stuff until that's disproven. YMMV.

You'll forgive me for my impatience, but I'm keen to see if there are any additional benefits(in humans) to a diet this lopsided over a diet that is simply low carb.

[lyn64]

While we're discussing fat cell 'nuking' Gabriel, I've seen freruent mention that, although it is a very long term prospect (years not months), fat cells that have as you described, 'become smaller', 'can' eventually atrophy and are reabsorbed. What do you know of the physiology of fat cell senescence? I mean all cells have a finite life span don't they? Aren't all the cells in our body replaced on a regular basis? Is there some biological imperative that says that once a fat cell is created it will always be eventually replaced rather than just allowed to eventually die and NOT be replaced?. In any case, what is the 'life span' of a fat cell?

Presumably the macronutrient ratio means of losing weight long term and effectively leaving fat cells without much to do for years is irrelevant as long as the weight loss is maintained.

Put another way, do fat cells that spend years without getting any fat just shrivel up and DIE.... rather than just shrivelling up.

Lyn

[Gaelen]

As long as food isn't entertainment or some kind of security blanket, why couldn't one stick to meat and water?

Well, Dan, for those rare birds for whom food isn't entertainment, or a security blanket, or a pleasure, or a satiety to some element of the senses, sticking to 'meat and water' is possilbe. There's no question that someone who was fed (note: 'was fed,' not 'chose to eat') nothing but meat and water would survive although there could be some vitamin deficiency issues; there's no question that people who only have access to certain limited types of foods, and eat nothing else every day, are alive right this minute.

The problem comes when personal choice comes into the equation. Most people, even those who think they could live on nothing but X forever, eventually grow weary of their favorite food(s) when that's the only thing on the menu. Tastes change. People change. And sometimes, a favorite food gets...boring! Even I don't have a cinnamon chocolate mocha protein shake every day...much as I love them...and I invented it, so I know exactly how good it can be. But there are days when it tastes 'off.' Only on very rare occasions can I manage more than one of them a day...if I had to drink one three times a day for infinity, I probably wouldn't last two weeks. And there are times when I can't even smell one, much less drink it. Who knows; maybe it's a commitment issue. ;)

I've heard lots of stories from people who say "I've lived for months on nothing but (fill in the blank.)" Rotissierre chicken comes up often to fill that blank--and so do pizza, doughnuts and coffee, for that matter. But people always eventually end up branching out...why do you suppose that is? Could it be that humans are hard-wired as omnivores--to survive, we're genetically engineered to make the best use of whatever foodstuffs were available to us. That's how we survived, that's why we're here today...because we have flexible enough tastes to find whatever foodstuff isn't moving faster than we are edible. ;)

The fat fast works because its 1000 calories/day. You'd have to be a mutant for that not to work.
Or someone very small. ;) It may work, temporarily...but how many people do it and then experience weight gain when they resume a more varied diet?

And Bear (http://thebear.org/essays1.html#anchor496162) (whose site was my first exposure to lc) has been doing zero carb for almost 50 years.
So he types. He's also typed a lot of other stuff that I'd class as YMMV. The choices he describes, if he's actually done what he says he's done, are choices not many others would be willing to make, or to sustain. Applying his diet to 5 billion other humans, or even to yourself--well, good luck with that. ;)

You'll forgive me for my impatience, but I'm keen to see if there are any additional benefits (in humans) to a diet this lopsided over a diet that is simply low carb.

Why? Not judging here...just curious. In a situation where the two outcomes might just be mutally exclusive, what is the greater benefit--getting healthier faster, so that you can be healthy for a brief period before you lapse into less healthy habits? or getting healthier sustainably, so that you amass health benefits and healthier habits that stick with you for the rest of your life?

[Gabriel Guzman]

While we're discussing fat cell 'nuking' Gabriel, I've seen freruent mention that, although it is a very long term prospect (years not months), fat cells that have as you described, 'become smaller', 'can' eventually atrophy and are reabsorbed. What do you know of the physiology of fat cell senescence? I mean all cells have a finite life span don't they? Aren't all the cells in our body replaced on a regular basis? Is there some biological imperative that says that once a fat cell is created it will always be eventually replaced rather than just allowed to eventually die and NOT be replaced?. In any case, what is the 'life span' of a fat cell?

Presumably the macronutrient ratio means of losing weight long term and effectively leaving fat cells without much to do for years is irrelevant as long as the weight loss is maintained.

Put another way, do fat cells that spend years without getting any fat just shrivel up and DIE.... rather than just shrivelling up.

Lyn

I remember somebody asking me the same question on the old board before we had to close it down. I will look for the articles I based my answer and then come back (unfortunately, I didn't save a copy of that reply). What I seem to remember is that indeed, there is a life span to fat cells but it's not days or weeks. It had to do with apoptosis (programmed cell death). I'll find those articles in my library again so I can structure a better answer.

Something we need to be clear is that, as Gaelen wrote, is virtually impossible to have zero fat. That is incompatible with life and I've seen that only in transgenic mice. When that happens in humans, as it is the case of lipodystrophia, a whole array of problems come with it and it is not a 'natural' state. Finally, addressing Dan's question, there is no more benefit in going lower than 30 ECC in terms of losing more or losing faster. The risk, on the other hand, as Billie put it, is to lose interest in keeping with that way of eating.

Just yesterday, Billie and I had a short discussion about 'low-carb' diets with some friends. I was very quick in making clear that 'low-carb' doesn't mean and shouldn't mean 'zero-carbs' and it is a misconception that when one goes 'low-carb' invariably one has to eliminate them. While there is nothing intrincically wrong with that (after all, there are humans that live on near-to-zero carb without problem), in our environment that would only bring boredom. The trick, or rather the learning is in 'management' of carbs.

Anyway, thanks for the discussion. I'll look for those papers and get back to you!

[mcsblues]

I remember somebody asking me the same question on the old board before we had to close it down. I will look for the articles I based my answer and then come back (unfortunately, I didn't save a copy of that reply). What I seem to remember is that indeed, there is a life span to fat cells but it's not days or weeks. It had to do with apoptosis (programmed cell death). I'll find those articles in my library again so I can structure a better answer.

It was me. See? - not a one track record!;)

If I recall correctly we were talking about a turnover up to eighteen months or maybe more - that and the large size of the fat cells makes them difficult to study.

[Gabriel Guzman]

It was me. See? - not a one track record!;)

If I recall correctly we were talking about a turnover up to eighteen months or maybe more - that and the large size of the fat cells makes them difficult to study.

Great!!! And Thanks! :thumbsup: Did you happen to save a copy of that discussion?:o I'll try to find the articles anyway! :)

[mcsblues]

Sorry, I don't think so - I thought I might have cut and pasted a bit of your reply, but I can't find it now.

While we are on the subject, I hope one of you hardworking moderators is in charge of backing up the resource this forum represents, so we don't ever have that situation again (where we lose the lot:tear:).

[Viking Dan]

Well, Dan, for those rare birds for whom food isn't entertainment, or a security blanket, or a pleasure, or a satiety to some element of the senses, sticking to 'meat and water' is possilbe.
I think you've misunderstood. I am curious as to whether this can accelerate fat loss. Its not neccessarily something I would do for life.

I've heard lots of stories from people who say "I've lived for months on nothing but (fill in the blank.)"
OTOH, in the absence of high levels of carbs, I am perfectly able to eat the same thing day in-day out. Eating then is like showering. Its something that needs to get done but doesn't have to be particularaly exciting.

Could it be that humans are hard-wired as omnivores--to survive, we're genetically engineered to make the best use of whatever foodstuffs were available to us. That's how we survived, that's why we're here today...because we have flexible enough tastes to find whatever foodstuff isn't moving faster than we are edible.
I don't dispute that at all. We are omnivores. However, just because people have been able to survive eating their shoe leather, for example, doesn't mean its optimal.

So he types. He's also typed a lot of other stuff that I'd class as YMMV. The choices he describes, if he's actually done what he says he's done, are choices not many others would be willing to make, or to sustain. Applying his diet to 5 billion other humans, or even to yourself--well, good luck with that.
Having spoken to the man, I have little doubt he does what he says. But even if he hadn't, Stefansson and the Inuit had/have. For that matter, I'm not sure you're not wolfing down a box of Dunkin Donut munchkins right now. ;)

As for how applicable the diet might be. Do you really think humans vary *that* much? If so, is there some human out there whose optimal diet is bricks?

Why? Not judging here...just curious. In a situation where the two outcomes might just be mutally exclusive, what is the greater benefit--getting healthier faster, so that you can be healthy for a brief period before you lapse into less healthy habits? or getting healthier sustainably, so that you amass health benefits and healthier habits that stick with you for the rest of your life?
Why should they be mutually exclusive?

The reason this study intrigues me is it demonstrates an effect at zero carb that doesn't occur in other two diets, and is not related to a difference in calories or %protein. If it occurs between 0 and 35% carbs also---great. If not, wouldn't 0 be the best place to start experimenting?

Something we need to be clear is that, as Gaelen wrote, is virtually impossible to have zero fat.
Right. I know a certain % is essential. I doubt any variation of diet (even starvation) could take someone to 0 bodyfat.

Finally, addressing Dan's question, there is no more benefit in going lower than 30 ECC in terms of losing more or losing faster.
Which is what I thought until I saw this article. I'm not a rat obviously, so maybe this is meaningless in humans. But, are you aware of any studies that compared "low carb" to "zero carb"?

[Gaelen]

I think you've misunderstood. I am curious as to whether this can accelerate fat loss. Its not neccessarily something I would do for life. ... OTOH, in the absence of high levels of carbs, I am perfectly able to eat the same thing day in-day out. Eating then is like showering. Its something that needs to get done but doesn't have to be particularaly exciting.

And I am curious why you would *want* accelerate fat loss... ?
While I've known lots of people for whom eating can become "something that needs to get done but doesn't have to be particularly exciting" for a while, a defined time period, there are all kinds of stats that illustrate that most people can't sustain this in the presence of other, more attractive choices. The one part of my post that you didn't quote comes to bear here, for nearly everyone, at some point in time:

The problem comes when personal choice comes into the equation. Most people, even those who think they could live on nothing but X forever, eventually grow weary of their favorite food(s) when that's the only thing on the menu. Tastes change. People change. And sometimes, a favorite food gets...boring!

While eating the same exact thing (to use your example, meat and water) for every meal, every day, might work for you, the stats that from 75% to 95% of all weight loss/controlled menu attempts FAIL (percentages depend on source) indicates, to me, that a significant group of the people who try to limit their menu choices have a strong tendency to be unable to stick to their limited menus (and that applies to low carb menus, too--some people really can't do it.) Individuals may be different, and anyone can handle a limited menu for awhile...but the duration of "awhile" differs from person to person (and no doubt, menu choices impact that, too.)

But the thing that intrigues me is why people think that they can artificially limit things temporarily, and expect to maintain their fat loss or other positive results when they eventually widen their menu horizons. One of the selling points of Protein Power, for me, is that from the beginning you can eat anything you want that fits within the protein/ECC recommendations for your stage of the plan. The Eades' tell a story in PP about a patient who used to spend 17 of his daily ECCs on a Snickers bar...because it kept him motivated. They didn't recommend it as the best way to control carbs; what they used the story to recommend was figuring out what would keep you on plan, and doing it--while being conscious that this is a lifelong commitment to eating better, not something you try to 'accelerate fat loss.' Why? Well, because stats also show that when people use a very limited menu to lose weight or fat, they often gain back a percentage or all of what they've previously lost when they leave their limited menu and expand their food options.

re: 'The Bear'
Having spoken to the man, I have little doubt he does what he says. But even if he hadn't, Stefansson and the Inuit had/have. For that matter, I'm not sure you're not wolfing down a box of Dunkin Donut munchkins right now. ;)

My point exactly...when you read an account on-screen, you takes your chances to some extent about whether the situation actually went down exactly as described. BTW, far more likely a pint of Ben and Jerry's for me--or a plate of coconut macaroons. ;) What I meant is that the average reader has no way to know for sure in the Bear's account. On that score, the research into the Inuit diet stands up a little higher, because the observers and recorders had nothing to lose in documenting what they saw.

As for how applicable the diet might be. Do you really think humans vary *that* much?

Yep, I do...we're not only talking about physical needs here; personal choice plays a part in having been hard-wired as omnivores. Put that into the equations, and humans vary immensely between cultures, between individuals, in many areas. Change your limited diet to "fish and water." Would you live on only that for an extended period of time? I'm not talking a fish you LIKE...pick something you would never eat, but that is equally good for you--maybe mackerel, or herring, or tilapia or octopus. How about "eggs and water," or "soy protein and water?" Can it be done? Sure. Does it provide any special benefits? That depends on who you talk to... ;) But eggs, fish and soy protein in some forms are all equally bio-available to human beings, some even more bio-available than beef, pork or poultry. And the one thing they all share, besides bio-availabilty, is that some people are different enough to be unable to tolerate each of them.

The reason this study intrigues me is it demonstrates an effect at zero carb that doesn't occur in other two diets, and is not related to a difference in calories or %protein. If it occurs between 0 and 35% carbs also---great. If not, wouldn't 0 be the best place to start experimenting?

Not in my opinion...
What if the result is more affected by the total grams of carbs eaten, and not by their percentage in the total diet?
What if the result is affected by the amount of fiber those carbs contain?
What if fresh vegetables give one result but fresh fruit another?
Questions, questions...there are lots of ways to investigate this, but since dietary results aren't linear, you need a lot of test subjects and you need to tightly control the experimental conditions...and you still may not end up proving the hypothesis that kicked off your investigation.

[Gabriel Guzman]

I don't dispute that at all. We are omnivores. However, just because people have been able to survive eating their shoe leather, for example, doesn't mean its optimal.


So far, nobody has ever proven that what the true Inuit subsist on is not optimal whereas the studies showing that eating the way we (in general) do is slowly killing us.


Which is what I thought until I saw this article. I'm not a rat obviously, so maybe this is meaningless in humans. But, are you aware of any studies that compared "low carb" to "zero carb"?

No to my knowledge and I don't think that anyone will ever do that due to ethical issues. I don't think that any study that propose to feed humans 'zero' carb would be received with good eyes. After all, "dietary carbohydrate is essential for life, right?" (big sarcasm here!)

The evidence that it is possible to do so comes from observational studies of people who still live that way... and they dont' have 'zero' fat.

I think sometimes we get so entagled with the nitty gritty that we just miss the big picture. We want everything 'literal' and we even jump to conclusions because something happens to rodents when we aren't. I really don't see anything intriguing about that study. They don't show 'zero' fat as a result of 'zero' carb. They show fat mass decrease as well as cell number, which to me is the important message and that seems to happen in humans as well when carbohydrates are not the main component of the diet. The body has amazing mechanisms to prevent us to go 'zero' fat, regardless. I could mention leptin, which is produced by the adipose tissue. Should the adipose tissue go dangerously low, there is a trigger of not one but several mechanisms that will induce feeding in order to regain adiposity to a point where other negative feedback mechanisms will be trigger to stop feeding so there is no more adiposity gained. It's not surprising that there is not one but several redundant mechanisms that are triggered in response to something like losing fat to the extreme because that meant survival in ancient times. But the way they interact is still so mysterious even though we discover just a little piece of the puzzle every day. So, think of just low this and high that is too simplistic and sometimes even unrealistic if we lose sight of the big picture. Yet, studies like these do provide important clues and I take them for what they're worth and with a pinch of salt because after all, we aren't rats.

[Viking Dan]

And I am curious why you would *want* accelerate fat loss... ?

:confused: As opposed to making it as excruciatingly slow as possible? :confused:

But the thing that intrigues me is why people think that they can artificially limit things temporarily, and expect to maintain their fat loss or other positive results when they eventually widen their menu horizons.

You've just described most low carb plans.

when you read an account on-screen, you takes your chances to some extent about whether the situation actually went down exactly as described.

Bear wasn't chosen at random. He's somewhat of an infamous figure in the Greatful Dead's history. They lived with the guy for some time and literally all he would allow in the house was meat and milk. Fascinating fellow.

Yep, I do...we're not only talking about physical needs here; personal choice plays a part in having been hard-wired as omnivores.

I specifically meant do you think humans vary that much biologically. Whether they drive on the left side of the road or speak French is not of interest to me for the purposes of this discussion.

What if the result is more affected by the total grams of carbs eaten, and not by their percentage in the total diet?

The result that interests me was specifically seen at zero.

So far, nobody has ever proven that what the true Inuit subsist on is not optimal whereas the studies showing that eating the way we (in general) do is slowly killing us.

Right. Again, I'm not concerned with food being "interesting." If you want variety in your life, take a walk or read a book or something.

I don't think that any study that propose to feed humans 'zero' carb would be received with good eyes. After all, "dietary carbohydrate is essential for life, right?" (big sarcasm here!)

Yes. Very dangerous. ;)

The evidence that it is possible to do so comes from observational studies of people who still live that way... and they dont' have 'zero' fat.

Wow. I know I come off as dense some times, but I don't expect(or want) to hit 0% body fat. If something a bit more stringent can get me into the teens faster, I'm willing to give it a shot.

Thanks. I appreciate all the commentary. If you know of any "no carb" studies, I'd be interested to see them.

[Bratface]

Viking Dan,

Did you ever actually find any studies on zero-carb diets? I find this topic interesting as well.

Bratface

[maxlharris]

Wow, fascinating topic.

On the "Expect to get there with one diet, and maintain with another" theme, isn't this kind of what Atkins NDR is? You start with 2 wks to 6 months of 20g ECC, then expand and find Critical Carb Level for Loss. Lose more, experiment more, get to goal and expand, finding your Maintenance Level of Carbs. In fact, that seems a lot like PP. Keep it low, 35, till you get close to goal, then switch to maintenance, where your protein:carb ratio might look something like 1:1. I think, in weight loss right now, my P:C is like 4:1 or higher (depends on the day... typically, I think I'm getting about 160G Pro to about 25G carb, which is 6+:1).

I concur that 0 carb is probably not the best place to stay, but I am a foodie, so cannot imagine severely limiting myself on the enjoyment of food. I like it too much.

But, if you are curious for the tipping point between 35% and 0%, why not start at 20% and work your way down? If you don't see the effect you are looking for at 20%, roll it down, if you do, roll it to 21% and reobserve. Or, pick some other arbitrary middle point.

Lastly, very hard to set your food up like they set up a lab rat's. Exact percentages, etc, seems like more work than value, especially when the 30-40G carbs works very effectively for most. On my other newsgroup, there is a man who suggests that Atkins Style OWL (start at 20g, add 5G a week, experiment with different foods, find your CCLL, and hang there) works best and has studies backing that up. My experience is that OWL leads to some stalls, some close monitoring costs (like I have to take time to journal everything and tie it to a scale reading that may be garbage anyway two days hence), and can go far astray. So, I like it where it's at.

I lose very quickly when:

I keep calories below 2500 but above 1500 (you need some fuel to stoke the fat burning fires)
I do vigorous exercises (sprint interval sessions seem to help, as do circuit weight training)
carbs are below 40 (haven't ventured north in a systemic way yet)
I eat five meals during the day.I consider more than a LB/week to be fast.

If you want to lose faster, I suggest other ways of monkeying with what you are doing. Try eating more smaller meals (my five works out like this: Breakfast shake, protein bar, lunch, small snack like almonds, jerky, or cheese, a real dinner, but smaller). Try doing some cardio. Try changing your cardio to Sprint Intervals. Lift weights. Change how you lift weights. Lift in Circuits. Change your circuit routine. Build more big muscles (work your legs, back, chest, and shoulders... you can build these fast if you aren't working them now, and they can grow big quickly). Start a walking program (walk quickly). There are a lot of ways you can Shake Sh!T Up to move your diet. Try upping your calories.

Last thing, VD. So, I think that calories do matter, but at the same time, I think you have to have a certain level or your body will conserve resources. If you are gonna do 20-40 minutes of lifting or cardio, you will need something to burn quickly, and if you are doing Sprint Intervals, the research shows that you can have a metabolic raising afterburn of up to 48 hours that will make your body burn more calories, and those calories can come from your stored adipose tissue. If you build muscle, it will burn more calories, just watching American Idol. So, maybe you want to tweak the metabolism before going all fat cell nuke. It will probably be more sustainable that way.

[Viking Dan]

Viking Dan,

Did you ever actually find any studies on zero-carb diets? I find this topic interesting as well.

Bratface

Nothing on humans...unless you count the Stefansson study at Bellvue(was it Bellevue?)