Saturday, January 26, 2008

The myth of fruit and more Taubes


Just to highlight a couple of interesting bits from the newspapers this last week.

On Wednesday, the Guardian had a really thought provoking piece on fruit. Not low carb by any means, but certainly saying that the current focus on fruit in the diet is not necessarily healthy:

The myths of fruit

Fresh fruit is good for us, we believe - so much so that sales of prepared fruit have almost doubled in the UK in the past two years. But are all those ready-sliced apples, mango medleys and 'superfood' smoothies really such a healthy choice? Aida Edemariam investigates
Then the Daily Telegraph had an interview with Gary Taubes:

Big fat lie

For years doctors have held that the only way to lose weight is to eat less fat and take more exercise. But now an eminent science writer says they've got it wrong. So, asks Melissa Whitworth, could Atkins have been right all along?
I liked Taubes' realistic comment:
Gary Taubes: 'If I was writing about me, I’d assume that I am both wrong and a quack.'


And the conclusion of the article, which is pretty close to my current thinking (although I think there is still something about exercise and also fasting which can have interesting hormonal effects of their own):


Weight-loss the Taubes way

  • Expending more energy than we consume – exercising more or eating less – does not make us lose weight. It makes us hungry
  • Dietary fat is not a cause of obesity or heart disease. The problem is the carbohydrates in our diet, and their effect on the hormone insulin
  • Insulin makes us store calories as fat. Simple carbohydrates – starches and sugars – raise insulin levels and so lead to excessive fat storage
  • The smaller the amount of fattening carbs you eat, the leaner you’ll be
  • Obseity is not a disorder of overeating – it’s a disorder of excess fat accumulation. We overeat because we are hormonally driven to grow fat; we don’t grow fat because we overeat
UPDATE

Seth Roberts
has done a fantastic and wide ranging interview with Gary Taubes here:

Basically, the way we work, at least if you believe the biology that I describe, is that as we secrete insulin in response to the carbohydrates we consume and the insulin works, among other things, to facilitate the movement of glucose into the cells of your muscles and other lean tissues. But blood sugar is kind of toxic, so your muscle tissue doesn’t want the insulin pushing all this blood sugar in, and it becomes insulin resistant. Your fat tissue now remains insulin-resistant, because your body doesn’t like to waste fuel. So if you eat a high-carb diet, your lean tissue takes up some of the glucose for fuel, and the rest gets dumped in your fat tissue, and your fat tissue remains insulin-resistant for a long time --- far longer. Because once your fat tissue becomes insulin resistant, then you just become diabetic; you have no place to put the glucose. You just pee it out. That’s the last resort, because your body doesn’t want to waste fuel.





20 comments:

randy said...

I really enjoy your blog site and look forward to checking in for you latest posts. I all too rare to find an evidence based support to your assertions.

Unfortuneatly, when it comes to carbs, calories and Taubes, your normal objectivity is thrown out the window.

Virtually all metabolic ward studies when calories and macro-nutrient are tightly controlled show the ONLY calorie count regarding weight gain. You seem to be unaware of this massive data set.

Some of these studies have been done on folks with metaboloic syndrome and the result remain the same: Only Calories Count!.

For a review of data check out this summary:
http://www.thefatlossbible.net/They_Are_All_Mad.pdf

Here's links to some of the other studies:

http://www.thefatlossbible.net/They_Are_All_Mad.pdf

Chris said...

Randy thanks for the comment.

I've read Colpo's stuff - and while I really like his stuff on cholesterol - I do think there is more to it than calories.

Eades answers Colpo Hereand he points to other papers that give another side to the debate that you might want to look at

Chris said...

Randy - have a look at


"A calorie is a calorie" violates the second law of thermodynamics




Thermodynamics� and� Metabolic �Advantage� of� Weight�Loss�Diets

Chris said...

And another one:

Do calories really count

randy said...

Chris,

Eades response is vacuous, lacking in empirical support. Something that I thought you would recognize.

The Feinman paper was a theorethical publication that was thrashed in the professional press specifically because its claims are contradicted by empirical data:
Here's an excerp:

//*********************************//************************
Reply to AH Manninen and to RD Feinman and EJ Fine
Andrea C Buchholz and Dale A Schoeller
Department of Nutritional Sciences
University of Wisconsin-Madison
1415 Linden Drive
Madison, WI 53706


Dear Sir:


We thank Manninen and Feinman and Fine for their interest in our
review, "Is a Calorie a Calorie?" (1). These 2 letters correctly point
out that there are indeed some differences between the energetics of
human metabolism and the measures of heat release of nutrients in a
bomb calorimeter. We agree with the known concept that the metabolic
route through which carbon flows to carbon dioxide, the concentrations
of substrates, as well as entropy can all slightly alter the
efficiency of ATP production in humans (2). This concept, however,
does not automatically mean that these differences constitute a
quantitatively plausible mechanism that would explain the differences
in weight loss observed with a high-protein, energy-restricted diet
relative to a low-fat, energy-restricted diet.


Rather than relying on a theoretical treatment of metabolic
efficiencies, as did Feinman and Fine, we reviewed studies in which
known experimental diets were fed to subjects under laboratory
conditions to test whether energy expenditure was actually higher with
a low-carbohydrate diet than with a high-fat diet. In studies in which
protein intake was held constant and fat was substituted for
carbohydrate, the difference in 24-h energy expenditure between the
high-carbohydrate and high-fat diets was not different from zero (: -
19 ± 54 kcal/d). However, as clearly stated in our review, when the
protein intake was not held constant but rather increased from 15% to
30-35% of energy, 24-h energy expenditure did increase. We determined,
however, that the increase would be only 41 kcal/d for a 1500-kcal/d
energy-restricted diet. This would only increase weight loss by 0.04
kg/wk, or 0.44 kg over a 12-wk course of weight-loss treatment. It
should be noted that this is less than the 95 kcal/d calculated
theoretically by Feinman and Fine, and it has the advantage of being
based on experimental data. Thus, we do not disagree with Feinman and
Fine from the perspective of pure thermodynamics; in fact, we
presented evidence at the whole-body level that supports their point.
However, we found the experimentally measured differences in 24-h
energy expenditure, between subjects who followed a high-protein diet
compared with those who followed a high-carbohydrate diet, to be too
small to satisfactorily account for the differences in weight loss
observed after 12 wk of treatment with these 2 diets. Thus, this is
not a plausible mechanism to account for the observed increased weight
loss. The experimental data on energy expenditure provide evidence of
only a minimal metabolic advantage for low-carbohydrate diets.


We do apologize for not having cited Feinman and Fine's detailed and
well-written review, but the journal in which it was published appears
to be new and thus is not yet indexed in common biomedical databases.


REFERENCES


Buchholz AC, Schoeller DA. Is a calorie a calorie? Am J Clin Nutr
2004;79(suppl):899S-906S.[Abstract/Free Full Text]
Flatt JP. The biochemistry of energy expenditure. In: Bray G, ed.
Recent advances in obesity research. II. Proceedings of the 2nd
International Congress on Obesity. Westport, CT: Technomic Publishing
Co, 1978:211-27.
//*********************************

randy said...

Chris,
All the metabolic wared studies show that macronutrient content is not a factor in weight gain or loss. The data is overwhelming!
Only calories count.

This doesn't mean you have to abandon your low carb diet, but the refusal of many in the low carb community to accept this data shows a bias that is not worthy of the general tone of your evidence based site.

Here's a list of the metabolic ward studies:

http://www.medscape.com/viewarticle/493991_6
If a password is required, I suggest you join.


The full relevance of some of these studies is contained in the full
papers so the abstracts may seem incomplete.


Here's the metabolic ward studies:


Predictability of weight loss
W. M. Bortz
JAMA. 1968;204:101-105.


Kinsell LW Calories do count
http://tinyurl.com/38kzx8


Metabolic effects of substituting carbohydrate for protein in a low-
calorie diet: a prolonged study in obese patients.
http://tinyurl.com/38gejt


Metabolic effects of carbohydrate in low-calorie diets.
http://tinyurl.com/2wkonk


Energy intake required to maintain body weight is not affected by
wide
variation in diet composition
http://tinyurl.com/2lxpub


Protein metabolism during weight reduction with very-low-energy
diets:
evaluation of the independent effects of protein and carbohydrate on
protein sparing.
http://tinyurl.com/34wl5o


Is a calorie a calorie?1,2,3,4
http://www.ajcn.org/cgi/content/full/79/5/899S


Some Metabolic Changes Induced by Low
Carbohydrate
http://www.ajcn.org/cgi/reprint/20/2/139?maxtoshow=&HITS=...//


Fat, Carbohydrate, Salt,
and Weight Loss


http://www.ajcn.org/cgi/reprint/20/10/1104?maxtoshow=&HITS=10&hits=10...


Similar weight loss with low- or high-carbohydrate diets
http://tinyurl.com/2ta9gn


Effect of a high-protein, energy-restricted diet on weight loss and
energy expenditure after weight stabilization in hyperinsulinemic
subjects
http://www.nature.com/ijo/journal/v27/n5/abs/0802270a.html


Is a calorie a calorie
http://www.ajcn.org/cgi/reprint/79/5/899S.pdf


Effects of an 8-Week High-Protein or High-Carbohydrate Diet in Adults
With Hyperinsulinemia
http://www.pubmedcentral.nih.gov/articlerender.fcgi?&artinstid=1868379
Ketogenic low-carbohydrate diets have no metabolic advantage over
nonketogenic low-carbohydrate diets.
http://tinyurl.com/2opt67

Chris said...

Randy - there is a lot of material about this on both sides. I happen to be more convinced by the arguments of Eades e.g. http://tinyurl.com/2krpre

or the paper here

http://www.sportsnutritionsociety.org/site/pdf/Manninen-JISSN-1-2-21-26-05.pdf

I'll have a look thoht the papers you quote though

Thanks

Chris

randy said...

Chris,

I've provided NUMEROUS human studies where subjects were locked up for months and the diet varied from extremes of carb, protein, fats.

You provided theoretical discussions that conveniently ignore the massive metabolic ward studies in favor of one rodent study and opinions based on belief.

Data rules and you ignoring the data!!

Randy

Chris said...

Randy

there is not much point in going on like this. I haven't had the time to look up the studies to which you refer above. I will do.

Data rules? Maybe but it still has to be interpreted and few experiments are free from error or confounding factors. I'm not being dogmatic about all this, but I still think Eades has a point in the post about the rodent study. Feel free to disagree. I don't have any great emotional investment in this - I just find it all interesting.

randy said...

Chris Wrote:
Data rules? Maybe but it still has to be interpreted and few experiments are free from error or confounding factors.

Reply:
Considering that there's about 20 human metabolic ward studies that that show its only calories and the best Eades can do is one rat study, I'd say the weight of the evidence against Eades.

Also these studies, unlike many, are very clear cut.
Lock some folks up for a couple of months. Feed them diets of known composition and quantity, control activity, and take the result. Even when they do this to type 2 diabetics no difference is found regading carbs, fats and protein.

Once again I REALLY enjoy your site and enthusiasm, but your not being ogjective here.

For a insisive review and summary of the studies check out Colpo's
"Fat Loss Bible".

Regards
Randy

Paul said...

Randy,
Are the links you posted the "tightly controlled metabolic ward studies" that colpo tries to use to provide "proof" that there's no metabolic advantage to low-carb diets? If so, he's a joke. I went through everyone I could find on your list and here's what i got:
Predictability of weight loss
W. M. Bortz JAMA. 1968;204:101-105.
Couldn’t get abstract or article.

Kinsell LW Calories do count
http://tinyurl.com/38kzx8
Couldn’t get abstract or article.

Metabolic effects of substituting carbohydrate for protein in a low-calorie diet: a prolonged study in obese patients.
http://tinyurl.com/38gejt
Could only read abstract, but very low cal (600-800 kcal).

Metabolic effects of carbohydrate in low-calorie diets.
http://tinyurl.com/2wkonk
Not controlled. The participants still went to work everyday. Both low carb, low cal (ketogenic) (hc at CHO 38 g/day) No mention of weight loss by authors.

Energy intake required to maintain body weight is not affected by wide variation in diet composition
http://tinyurl.com/2lxpub
not a weight loss study, a meta-analysis of weight maintenance diets done on patients in the 50s and 60s.

Protein metabolism during weight reduction with very-low-energy diets: evaluation of the independent effects of protein and carbohydrate on protein sparing.
http://tinyurl.com/34wl5o
very low calorie, all low carb (but still lc/hf outperformed hc/lf)

Some Metabolic Changes Induced by Low Carbohydrate
http://www.ajcn.org/cgi/reprint/20/2/139
Only low carb, no comparison group (1200 calories, 0% carbs)

Fat, Carbohydrate, Salt, and Weight Loss
http://www.ajcn.org/cgi/reprint/20/10/1104
800 calorie diets, low carb lost more weight. Not tightly controlled, they were allowed out of the ward twice a week.

Similar weight loss with low- or high-carbohydrate diets
http://tinyurl.com/2ta9gn
both diets low carb low calorie (high carb was 115 grams, 1000 kcal). Lower carb lost more weight.

Effect of a high-protein, energy-restricted diet on weight loss and energy expenditure after weight stabilization in hyperinsulinemic subjects
http://www.nature.com/ijo/journal/v27/n5/abs/0802270a.html
Not low carb

Is a calorie a calorie
http://www.ajcn.org/cgi/reprint/79/5/899S.pdf
Not a study.

Effects of an 8-Week High-Protein or High-Carbohydrate Diet in Adults With Hyperinsulinemia http://www.pubmedcentral.nih.gov/articlerender.fcgi?&artinstid=1868379
No low carb group

Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets.
http://tinyurl.com/2opt67
Not a metabolic ward study

Laughable!!!! You better get some more evidence, cause that's lame.

Bruce said...

Randy, here is the problem with the vaunted metabolilc ward studies Mr. Colpo constantly hypes. They didn't compare obese people with others of normal weight. I looked at a few of these studies and they were looking at one or the other. What does that prove? Also, Eades has said that if there is any metabolic advantage to weight loss, it's very small. A few hundred calories at most. He argues that the major advantage is "weight maintenance." In short, you can eat more food on high-fat low-carb diet without weight/fat gain. Colpo has totally ignored this issue, because he only talks about weight loss. It is Colpo who is laughable, as Paul noted. His studies are all a joke.

malingering said...

Paul:

Have you gone through the low-carb studies with the same amount of scrutiny? I'm just asking because I haven't. I haven't found many low-carb studies that are particularly impressive, but I haven't looked all that hard.

Razwell said...

Why does it not occur to people that Anthony Colpo is a pure neophyte when it comes to science?

Anthony Colpo has NEVER shown he is QUALIFIED or has the CREDENTIALS or was trained to properly interpret scientific literature.


Please do not give this amateur anymore attention. In the scientific community it is common to ask someone their CREDENTIALS. There is NOTHING wriong with this. Ask Anthony Colpo his and he accusses you of " ad hominem attacks". He does not even know what the word means.All Anthony Colpo can do is DEFLECT attention from his sorry, complete LACK of credentials.

No one in the scientific community takes Colpo seriously . ( the very few who even know who he is)

Colpo is ONLY good for one thing- and that's riding on the COAT TAILS of Dr. Uffe Ravnskov......

Razwell said...

Why does it not occur to people that Anthony Colpo is a pure neophyte when it comes to science?

Anthony Colpo has NEVER shown he is QUALIFIED or has the CREDENTIALS or was trained to properly interpret scientific literature.


Please do not give this amateur anymore attention. In the scientific community it is common to ask someone their CREDENTIALS. There is NOTHING wriong with this. Ask Anthony Colpo his and he accusses you of " ad hominem attacks". He does not even know what the word means.All Anthony Colpo can do is DEFLECT attention from his sorry, complete LACK of credentials.

No one in the scientific community takes Colpo seriously . ( the very few who even know who he is)

Colpo is ONLY good for one thing- and that's riding on the COAT TAILS of Dr. Uffe Ravnskov......

Anonymous said...

I think the main point is that with these ward studies the calories are tightly controlled. Thats the problem in the real world calories aren't tightly controlled they are all around us. I think what taubes, chris and eades are meaning is that refined carbs cause us to eat more than we can burn off. I believe thats the main point of the "metabolic advantage". Someone on a low carb diet and not consuming grains and refined carbs naturally eat less.

Anonymous said...

It is hard to find any criticism of whole fruit. Even this article refers to "prepared" fruit not whole fruit. But what happened? It went off track and never mentioned fruit again for the rest of the article?

Anonymous said...

Correction: I forgot to click link to the fruit article. I didn't know it was embedded in the main article.

sharon said...

I read the article on fruit. Very poor. It's more about the booming retail market for prepared "value added" fruit salads and nothing to do with nutritional science or the negative health effects of whole fruit and fruit juice. One might think that the only concern here is sliced fruit salads. Not one mention of fructose or insulin and it's devastating impact on obesity, diabetes and heart disease via fructose and VLDL. The article takes too long to make it's point.

Anonymous said...

This post was suppossed to be about the myth of fruit as a healthy food. But there is nothing about this in the body of the text