las

Welcome all seeking refuge from low carb dogma!

“To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact”
~ Charles Darwin (it's evolutionary baybeee!)

Saturday, April 2, 2011

Calories, fat or carbohydrates? Why diets work (when they do).

It was inadvertently (I think) brought to my attention that, while constructing my Fasting Insulin & Weight Loss post, I had "in my hand" the perfect study to discuss the title of this post.

Does that title sound familiar?  It should!  Because this was the title of Gary Taubes' second blog post:
Calories, fat or carbohydrates? Why diets work (when they do)

As I've stated many times, unless someone provides me with a complimentary copy of Why We Get Fat, I'll not be reading the dumbed down version of GCBC, even for the groundbreaking new information it is purported to contain.   Reportedly, one of those groundbreaking items is a chapter on the very topic of that blog post.  A blog post that was a sort of preview teaser in advance of his book release.  But that post wasn't the first time he discussed this novel idea that he claims supports his alternate carbohydrate/insulin hypothesis.  

Most of my readers are probably aware of when ol' CarbSane here really hit Gary below the belt by playing on words,  "called Gary a sheister", and - GASP! - put a $ in his name, when I addressed his discussion of Shai in a lecture.  I guess the plays on words there using Shai-ster and Shai-t were just too much for his devoted followers to handle.  Who knew a $ could draw such ire!  I suggest if any of these things are going to throw you into ketogenic paranoid seizure, you click on that X in the upper right corner of your browser now.

Really ... I mean it!  DON'T click the "Read More" below if you can't handle it!!!  I'm gonna get nasty here!

Really really.

OK ... last warning (VVVBEG)

[ profanity warning] Or, you could grow a fucking pair, wipe the shit off your face from having your head up your ass for so long, and read on without all the Gary damned whining.  Crude enough for you?  Just channeling my inner Nikoley ;-)  I hear low carbers like this sort of thing from their bloggers ... but I digress ...  [ /profanity ]

Sorry folks.  Sweet li'l old vitriolic me is back.
  
In any case, here was my post:  Gary Taube$, Shai-ster  Gird your loins if need be and go read that post before reading on.  As a special treat, if you follow the links to Gary's lecture, you'll get to hear his now infamous gluttony quote.   Behave yourself Nigee! 

In a nut-shell, Taubes compares just the LC and LF groups in the Shai study.  He ignores the reported calorie deficit of the LC group, implies they ate more but lost more weight, and he attributes this to the fact that it is carbohydrate restriction that produces weight loss.  This, he says, is why the LF group lost some weight, but less:  they also reduced carbs but not as much as the LC group.  

Now, since I didn't stress this strongly enough in my original post, I will state it definitively now:  The dietary intake data from the free-living Shai study is, ultimately, USELESS to draw any conclusions regarding energy balance or attributing results to a particular variable.   A few days self-report for some of the subjects at 3 time points over a 2 year period just doesn't cut it!   

And yet in his blog post, after acknowledging just that (" the dietary records from these studies have to be taken with a grain of salt"), Gary goes on to base his entire argument on the basis of such flawed data.
Taubes:  Let’s concentrate on the low-fat, calorie-restricted diet and the low-carb, Atkins diet. The changes in dietary intake and nutrients for the “low-fat diet” are shown in the first column. As you can see after 24 months, the subjects eating the low-fat diet were supposedly restricting calories consumed on average by 572 calories. The reduction in carbohydrates consumed, though, was 330 calories (82.8 grams per day times 4 calories per gram), compared to only a 170-calorie (18.9 grams per day times 9 calories per gram) reduction from baseline in fat. So the “low-fat diet” reduced carbohydrates nearly twice as much as it reduced fat.
The low-carbohydrate diet, on the other hand (the third column), reduced carbohydrate calories by 520 calories per day (129.8 grams per day times 4 calories per gram) and fat calories by a mere 15 calories (1.7 grams/day times 9 calories per gram). So certainly the low-carb diet was correctly described as a low-carb diet, and the question we have to ask is maybe the weight loss seen in the low-fat diet was also due to the restriction in carbohydrates. 
Me:  Let's look at ALL of the data.  The Mediterranean diet, reduced carbohydrate calories by 202 calories per day (50.5 grams per day times 4 calories per gram) and fat calories by 95 calories (10.5 grams/day times 9 calories per gram). 
To summarize:  Total Calories/Carbohydrate Calories/Fat Calories we have: 
LF:   572/330/170                MDTN:  372/202/95                LC:  551/520/15
At 2 years, average LC & MDTN weight loss was the same and a bit more than the LF group.  Which tells us jack squat.
Taubes waxes sanctimonious over Shai and her colleagues painting them as some sort of clueless researchers who have never heard of confounding variables or how to control for variables in their study.  Poor Iris Shai, RD, PhD.  She'll never garner the respect of Mr. Gary Taubes until she analyzes her data to his high standards.  

It turns out that Shai's variable (singular) was simply the dietary intervention.  Period.  My take is that such studies as this are instructive to provide us with determining what type of intervention may be successful for the greatest proportion of people, for the long run, in real life.  As such, Shai couldn't even rigorously control for whether the participants adhered to their assigned program 100% or anywhere near.  That's the rub with all free-living studies.  They should never be used, then, for analyses that require data obtained in the constructs of such rigorous control.   If I have any criticism for Shai it would be perhaps that more detailed dietary records could have provided better insights.  Even self-report.  One day per week per subject for the entire study?  How about a 3 days each month per subject averaged?  Because the data, as they are, do not jive with the weight results, or Shai definitely doesn't look good for the low carbers:  significant gain back despite slightly increased carb restriction.  

So Taubes goes on:
It is quite possible that even low-fat, calorie-restricted diets work because they restrict carbohydrates and maybe the reason they don’t work as well as the low-carb diets is they don’t restrict them as much. Or maybe they don’t work as well, on average, because they also restrict fat calories when dietary fat has little or no effect on body fat accumulation. We don’t know if this is true or not, but it could be true, and until these researchers realize that another variable is changing significantly on these low-fat, calorie-restricted diets –  the amount of carbohydrates consumed — they’ll never bother to test it or take it into account in their interpretation of these clinical trials, and we’ll never know.
Go back and read the beginning of his post. 
... the value of controlling variables in a scientific experiment is something that a reasonably well-educated child supposedly understands. And what I want to know is why don’t nutritionists understand it and those researchers out there doing diet trials and studying obesity and weight regulation. Because their failure to do so — and I would argue that it may be a willful failure — has led to what may be another of the great misconceptions in modern nutrition research. In particular, that carbohydrated-restricted diets are “valuable tools” in the arsenal against overweight and obesity, but they’re just one of the dietary tools.
His usual condescension towards anyone who doesn't see things his way is apparent.  It's so simple, even a child can grasp it., but Shai is such a do do bird she and every other nutritionist or researcher just don't get it. This from a man who gave us that rigorous analysis (leaving out 1/3rd of the data) of data he, himself, states should be taken with a grain of salt.   Worse yet, he essentially accuses them of worse than stupidity, but willful failure.  OK, so it's fine for him to accuse millions of researchers and nutritionists of professional malfeasance, but I'm out of line for calling him out on his easily documented professional malfeasance?? 

Let's get back to controlling variables.  Taubes implies - and his followers apparently believe him - that all of these studies have never been done.  To repeat:
We don’t know if this is true or not, but it could be true, and until these researchers realize that another variable is changing significantly on these low-fat, calorie-restricted diets –  the amount of carbohydrates consumed — they’ll never bother to test it or take it into account in their interpretation of these clinical trials, and we’ll never know.
Oh, but Gary, my point is that, they actually HAVE tested this, in innumerable studies, and we DO know.  But Gary's words play to the victim mentality so prevalent amongst low carbers and they gobble it up it appears.


Cue "opening of heavens" music ... Ah AAAAAAAAAAH!

Behold  Grey and Kipnis:   This was an inpatient study where intake was carefully monitored and controlled.   
  • Protocol 1 - Effect of Carbohydrate Content in Caloric Balance:  Subjects ate ad libitum for 2 weeks to establish weight maintenance calorie needs ad libitum period, then fed at that caloric level for 3 weeks on a LC diet (C/F/P = 25/53/22), and switched to a HC diet (C/F/P = 62/18/20) for the final 3 weeks.    
So G&K's study design, to a well-educated child, controlled for calories and protein (slight differences), varied the carbohydrate/fat content of the diet and measured body weight, fasting insulin and glucose stimulated insulin secretion.  What did we find?  Apparently one subject refused some food and lost a bit of weight (apparently another gained ever so slightly too), but overall, the isocaloric diets maintained bodyweight independent of the carbohydrate content of the diet.  
  • Protocol 2 - Effect of Carbohydrate Content in 1500 cal CRD:  Here the subjects again established baseline for 2 weeks and were then cycled between 1500 cal formula diets:  4 weeks HC (C/F/P = 72/1/27), 4 weeks LC (C/F/P = 0/74/26) and finishing up with 4 more weeks HC.
Now I know it's probably lost on Grey and Kipnis, but again, our well educated child would immediately note that this IS a controlled study!  You can't get much better than this in terms of controlled study design.  My only qualm is the small sample size and that this was a rat study.  Oh wait ... correction ... they were human females.  The researchers used formula diets which basically minimizes differences in digestion on absorbed calories, controlled their intake in a supervised setting, controlled for total calories and protein, and compared an essentially fat-free diet to a zero-carb diet.  

The result?  All subjects lost weight in steady fashion despite the wild swings in the carbohydrate consumption.  And, an extra bonus, the two subjects with higher baseline caloric intake lost more than the subject with lower maintenance calories.  

CONCLUSION:  Controlling for calories and protein intake and varying carbohydrate/fat composition of the diet resulted in weight maintenance with intake at individualized maintenance caloric levels, and weight loss with intake at caloric deficit.  Diets work (when they do) when there is a consistent sustained caloric deficit.

S L O W L Y   N O W   F O R   T H O S E   S U F F E R I N G   F R O M   C.D.S:  
A study was done that controlled for calories (and as a bonus, protein) and varied carbohydrate content and measured weight loss.  Result:  weight loss was consistent independent of varying carbohydrate intake between basically all of non-protein calories and non of all-protein calories.  

Now I realize 1971 is a bit too contemporary for Mr. Taubes, but since he did reference a text published in 1972 he could have found this study were he interested.  

I think Mr. Taubes owes Drs. Grey and Kipnis an apology for his unprofessional, unethical, and downright below the belt assaults on their scientific abilities and integrity!  Don't you?

More installments may be forthcoming as needed.

Edit - Followup Posts:
Fasting Insulin & Weight Loss II
GCBC Reference Check ~ Part IV of ? ~ Kipnis

23 comments:

Christopher Robbins said...

Reminds me somewhat of posts by the low-carb paleo crowd that claim that all diets are high fat diets because you cannabalize your own fat stores.

Nigel Kinbrum said...

Behave yourself Nigee!
Eh? What did I do?

CarbSane said...

Hee hee ... I was referring to your "he'll never live that one down" comment elsewhere and linking to that video. LOL :-)

CarbSane said...

@CR: This is a new thing thanks to ... who else? GT :( So now we'll have legions of folks pondering why a high dietary fat high fat diet is more satiating than a low dietary fat high fat diet because Gary says protein isn't satiating, fat is. Things that could make ME go bald!

Christian said...

"Now I realize 1971 is a bit too contemporary for Mr. Taubes, but since he did reference a text published in 1972 he could have found this study were he interested."

Hmm, the only problem is that
a) Taubes read the study and
b) also interviewed the researcher and
c) the researcher himself comes to a different conclusion regarding his own study than you do.

Strange, very strange.

Maybe that is because this study has nothing to do with a "diet trial". If you enforce a caloric deficit your patients are going to lose weight (if they eat the meals that have been prepared), no argument. That is how you get people lean in a hospital. How do you get them lean at home where they make choices of their own (oh, how the variables are changing again ...), experience hunger and act accordingly? With a caloric deficit?

Your conclusion is: "Diets work (when they do) when there is a consistent sustained caloric deficit." Your main objection is that GT suffers from "partial" CDS. Sometimes he admits it, sometimes he says calories don't matter. Please watch this video to the one minute mark.

http://www.youtube.com/watch?v=XR3FVvEJ-Nk

As far as I can tell, this is precisely your "conclusion": Diets work (when they do) when there is a consistent sustained caloric deficit! "Absolutely no doubt about it." he says.

The thing is that Taubes starts with this no-brainer, acknowledges it and then tries to understand why we get fat and what to do about it. You on the other hand, start with the assumption that Taubes is an idiot, then you do your "study analysis" and then reliably arrive always at the same "conclusion" without realizing that you haven't gotten anywhere.

By the way in his book Taubes uses this study in part as an example to illustrate how endless reiteration of energy balance can lead to a "stall" in discussion and thinking - because any real reason, explanation or weight loss strategy is replaced by the "explanation" or "hypothesis" of weight loss and gain in terms of negative and postive caloric balance ...

Mirrorball said...

@Christian

How do you reconcile what he says in the video with the following quote from:
http://www.garytaubes.com/2010/12/calories-fat-or-carbohydrates/

"And they [researchers] also make the assumption that a diet that restricts total calories works (if it does) because it restricts total calories.
[...]
In doing so [controlling for carbs], it might have revealed something meaningful about whether the nutrient composition of the diet plays a role in weight loss or weight gain independent of calories, which is one of the critical questions here.
[...]
the question we have to ask is maybe the weight loss seen in the low-fat diet was also due to the restriction in carbohydrates. It is quite possible that even low-fat, calorie-restricted diets work because they restrict carbohydrates and maybe the reason they don’t work as well as the low-carb diets is they don’t restrict them as much. Or maybe they don’t work as well, on average, because they also restrict fat calories when dietary fat has little or no effect on body fat accumulation."

So do diets work "when there is a consistent sustained caloric deficit" or "because they restrict carbohydrates" independent of calories? He even goes as far as saying that fat calories have no effect on fat gain.

CarbSane said...

Awww Christian, you're just the gift that keeps on giving. Thanks for pointing out yet another reference and scientist Taubes displays scholarly incompetence in analyzing their work. More later.

Christian said...

You are welcome. Thats what I do.

Christian said...

@ Mirrorball: Every diet works "when there is a consistent sustained caloric deficit" because that is more a less what you want to accomplish: Get the system leaner (smaller) => take in less than you expend. There just is no diet that would work with a caloric surplus or caloric balance.

Ok, so once you said that (and everyone agreed), you can start thinking about how you really make that "work" for a large group of people because the above description just rephrases the goal we want to accomplish. As you might know, GT believes it all comes down to fat cell regulation. Manipulate the fat cell regulation for the best and everything else will follow. For example intake might adjust because you are not partitioning energy towards storage but towards expenditure which might have an effect on hunger/food cravings, i.e. caloric intake will go down. And/or expenditure will go up, because maybe you have a sudden urge to exercise or you unconsiously move a little more. BTW I am not saying I agree with all this!

This is just how I understand his theory. And I have no problem then reconciling the quotes with this theory and what he says in the video. Because if you believe what he believes, then you might hypothesize that even any conscious restriction in calories (which also cuts carbs) for a few days then effects fat cell regulation for the better, thereby allowing for the person to lose the weight (without hunger) for long periods of time and successfully adjusting intake. The effect then might falsly be attributed to the initial caloric restriction while in reality metabolic regulation was normalized which induced the successfull adjustment of intake and expentiture.

Now before you attack me because I am stupid and this is all nonsense here it goes again: I am not saying that I agree with all that. I am just saying this is how I understood his main ideas outlined in GCBC: Obesity is a disorder of excess fat accumulation. So what regulates fat accumulation.

That is the part where I more or less fully agree with him. Where I disagree with him is that its all about insulin and carbs.

Mirrorball said...

@Christian
I know you are just trying to paraphrase Gary Taubes' ideas.

He is discussing why a low-calorie diet has caused weight loss and implied it's not because it's lower in calorie, but because it's lower in carbohydrate. What CS has shown here is that when you force a certain level of caloric intake and expenditure, carbohydrate intake doesn't matter. You might get hungry but you WILL lose weight. Notice that he isn't interested in how the low-calorie diet affected hunger in his post; he is discussing weight loss, why the low-calorie diet caused weight loss. He talks about nutrient composition playing a role in weight loss INDEPENDENT of calories (his words quoted in my previous post). What CS wants to show here is that nutrient composition never plays a role in weight loss independent of calories and pondering why a low-calorie diet works is absurd. It works because it restricts calories, full stop. The efficacy of a diet is always dependent of calories, ie every diet works by making you eat less and/or spend more energy, spontaneously or not. And everyone here agrees that spontaneous is better, which is why CS is on a low-carb diet.

CarbSane said...

Nail on head. Thanks MB :-)

Karl said...

http://sparkofreason.blogspot.com/2008/06/swift-kick-in-asp.html

An interesting blog post that would seem to explain the role of ASP and why people have great success losing tons of weight on low-carb, but often stall at the last 10-20 lbs.

(No, it doesn't mean that GT is completely wrong, just that his theory is incomplete.)

Christian said...

"What CS has shown here is that when you force a certain level of caloric intake and expenditure, carbohydrate intake doesn't matter."

CS has shown? G&K have shown ;). And as I said the researcher didn't conclude that from the study. The "result" that you restate is a) not controversial and b) not interesting and c) predictable (as long as you are not believing in a metabolic advantage).

"You might get hungry but you WILL lose weight. Notice that he isn't interested in how the low-calorie diet affected hunger in his post;"

Aren't these diet trials he talks about? At least the Gardener study is. So why does he have to imply hunger? If I am at home hungry, I might eat. If I am in the hospital forcefed, I have no choice. An important variable changed.

"he is discussing weight loss, why the low-calorie diet caused weight loss. He talks about nutrient composition playing a role in weight loss INDEPENDENT of calories (his words quoted in my previous post)"

So you chose to interpret this as: if you fix two formula diets with exactly equal caloric content (enforcing a deficit) but varying macronutrient ratios, feed them to patients (who don't have a choice but to exactly consume those for a few weeks) you would expect different weight outcomes? Sorry I don't interpret it this way.

You can either interpret it this way and speculalate that he is referrring to a metabolic advantage.
Or you can interpret it in the context of a diet trial, where people make choices of their own and ultimately the success or weight loss (i.e. the final caloric deficit after the study finished) depends on these choices because they act accordingly. And then (if you believe what Taubes believes) you might speculate that even when one group is advised to eat low-fat low-calories, they are only able to enduce and sustain this caloric deficit for a few month or so because the carbohydrate content changed (ultimately because of normalized hormonal regulation I guess). For him then, the macronutrient ratio (or carbohydrate reduction) played the "important role", and not the fact that the patients where advised to eat fewer calories.

Again the disclaimer: My interpretation can be wrong, yours can be right. I just don't see any reason for your interpretation after having watched the video.

Frank said...
This comment has been removed by the author.
Frank said...

But Christian, according to this logic, a LC iso-caloric diet would indeed result in greater weight loss, regardless of the caloric deficit.

And if that was true, how does that reconcile with one study that James K posted, where the individual increased their CHO content while reducing the fat and steadily lost weight? Weight loss should be lower and lower as CHO content is increase in a diet, if we stated that weight loss is determine by CHO content independantly of the calorie restriction.

Otherwise i'm not sure i'm following you in your interpretation of what Taubes says.

Christian said...

"But Christian, according to this logic, a LC iso-caloric diet would indeed result in greater weight loss, regardless of the caloric deficit."

Sorry I don't understand what you mean. The caloric deficit directly corresponds to the weight (or fat) lost due to thermodynamic principles. Greater weight loss == greater caloric deficit.

If you feed two exactly iso-caloric diets for a particular amount of time (say a few weeks like in the G&K study) to patients and one is LC, one is HC then weight loss (= caloric deficit) should be identical under the assumption that there is no metabolic advantage and energy expenditure are similar for both groups.

"And if that was true, how does that reconcile with one study that James K posted, where the individual increased their CHO content while reducing the fat and steadily lost weight?"

I didn't say what Taubes says is true. I disagree with him. I said this is how I understand it. And as far as I understand Taubes, if they increase CHO and reduced fat, but kept losing weight, they were hungry (or hungrier than in the low CHO / high fat case). Can you link the study?

"Weight loss should be lower and lower as CHO content is increase in a diet, if we stated that weight loss is determine by CHO content independantly of the calorie restriction."

Maybe I see a fundamental difference between the terms "caloric restriction" and caloric deficit.

Caloric restriction is the advise in a diet trial to not exceed a certain caloric level (say per day). The rest is left to the patients (i.e. if they (can) follow the advise or how they follow it).

Caloric deficit is the weight (or fat mass) lost during the diet trial which is the outcome. No weight loss = caloric balance. Weight loss = negative caloric balance. Weight gain = positive caloric balance (according to the presentation by Gardener a substantial amount of people gain weight on these trials).

Then according to Taubes weight loss (= caloric deficits) in a diet trial should be inversely proportional to the CHO eaten by the patients - independent of any "caloric restriction" advise. (As far as I can tell, this is not the case.) However the G&K study (and other metabolic ward studies with prepared isocaloric meals) neither support or refuse this claim because they have nothing to do with it.

Frank said...

Hi Christian

Here's the study

http://www.ncbi.nlm.nih.gov/pubmed/10837283

So the only mechanisms by which Taubes assumption would be explain is that less carbs = less hunger? I'm not aware of any evidence that carbs per se have an impact on satiety. Fat and pro do. But I get that you don't believe everything he says.

The way I interpret what taubes says is that you don't need to care about calories as long as you care about carbs. It might not says that you don't need to restrict calories as long as you restrict carbs, but it sounds a lot like it, and that's the message that many people hear.

He clearly says that weight loss in independant of calories, only dependant of carbs. To me that sounds like "eat as much as you want as long as you're not eating carbs" and he's also saying that once you've plateau on LC, and can't get further LC, well, that's the weight that you should be at, whereas restricting calories from then on (and probably upping carbs) would make the weight goes down again.

So do you believe that only ad libidum studies are meant to test Taubes claims? Metabolic ward studies on isocaloric meals at least show that there is no metabolic advantage. Free living studies shows that LC brings a greater spontaneous calories deficit.

CarbSane said...

Christian, whether or not a study is a "diet study" or "weight loss study" is irrelevant. In G&K they were looking at fasting insulin levels, but the study controlled calories and protein while varying carb/fat. So, one such study Taubes laments will never be done because of willful failure on the parts of corrupted scientists and nutritionists WAS done. And it demonstrated that subjects maintained weight on maintenance calories irrespective of carbohydrate intake and basal insulin levels, and lost weight when calories were restricted - again irrespective of carb/basal insulin. QED. Taubes is an idiot. Actually I don't believe that. He's a genius. Just not at analyzing scientific data and presenting it honestly ....

Christian said...

@ Frank:

"To me that sounds like "eat as much as you want as long as you're not eating carbs""

I think that he believed this to be true in the beginning because of his false interpretation of the G3P issue. But that was a mistake and he admitted it. So no, drinking lard all day won't get you lean even though its 0 carb.

"and he's also saying that once you've plateau on LC, and can't get further LC, well, that's the weight that you should be at, whereas restricting calories from then on (and probably upping carbs) would make the weight goes down again. "

That's what he is saying.

"So do you believe that only ad libidum studies are meant to test Taubes claims?"

I wouldn't make such a general statement. I mean I am not sure if he believes there is a metabolic advantage or not.

@ CarbSane: No, its key, not irrelevant. The study demonstrates exactly what you say it demonstrates (even though it was obviously designed to demonstrate something else). The thing is that no one claims otherwise. But if you honestly think Taubes is saying that on isocaloric formula diets fasting insulin levels determine the final caloric deficit (= weight loss) then go disprove him. QED. Good job.

CarbSane said...

Key? To what?

Taubes claims studies have "willfully" not been done, and until they are we don't know. But they have been done. Whether or not it is the focus of the original researchers is irrelavent. Review papers, meta studies, and correlative analyses are published every day using data from studies to look at other parameters.

Taubes is guilty of exactly what he accuses everyone else of. He either has no clue how a properly controlled study is conducted or how to spot the controlled variable when he sees it. That he cited this study in GCBC is even more damning. GCBC Ref Check post in the works.

Christian said...

Key to a fair judgement apparently, as this seems to be a trial, Taubes is guilty and you are the judge :)

"Whether or not it is the focus of the original researchers is irrelavent."

That wasn't the point. Indicated by the brackets -> ( ... ) <-.

"He either has no clue how a properly controlled study is conducted or how to spot the controlled variable when he sees it."

Or, OR, .... no I wouldn't.

"GCBC Ref Check post in the works."

Looking forward to it.

Harry said...

@ Christian

I'm getting a bit lost on what you're actually advocating, as your views are typically interspersed with your defence of others' views (not necessarily your own).

So, can you advise as to your views on the following two propositions:

1) Low carb diets work (when they work) by reducing hunger and increasing satiety, thus discouraging the consumption of food, and thus creating an energy deficit; and

2) Restricted calorie diets work (when they do) by having subjects volitionally consume less food than is required to maintain current body mass.

Cheers
Harry

Christian said...

@ Harry, what I was pointing out is that the G&K study has nothing to do with those propositions. Because the proposition is not that on isocaloric diets the energy deficit is determined by fasting insulin levels. This would be madness ... and nobody is claiming this.

Do you agree with this:

A "working" diet is a diet in which the patient loses weight, i.e. the body/fat mass at the end of the diet is less than it was at the beginning of the diet. Then because of thermodynamics this is equivalent to saying that a "working" diet is a diet that is accompanied by an energy deficit. This means that over the course of the diet the patient took in less energy then he or she expended. Otherwise the diet would not have "worked".

I certainly agree with this (Taubes is, too - according to the video). My view is that proposition 1) could be true to some extend and proposition 2) is flawed. I don't think that all it takes is volitionally consuming less food than is required.

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