Medical Rise of Cancer: Examining the Role of Sugar and Refined Carbs

[bobze]

When studying the effects of various interventions on human health, it is notoriously difficult to glean actionable information from anyone single scientific study. Often these are observational studies that are subject to many confounding factors and limited by small sample sizes, poorly controlled conditions, and short observation periods. Even well-controlled, randomized clinical trials can often reach opposing conclusions.

We can reach better conclusions, however, by performing a systematic literature review: examining the scientific literature as a whole by using strict criteria to select the highest quality studies and evaluating the results of the all of the studies as a whole. Although there may be individual studies within the review that support either side of an assertion, if a large majority of the studies support one side of an argument, we can be much more confident about their conclusions.

The 2007 report, Food, Nutrition, Physical Activity, and the Prevention of Cancer by the World Cancer Research Fund and American Institute for Cancer Research does just this. I will summarize the relevant findings of the review below. The full report is available here: http://www.dietandcancerreport.org/

Because obesity is an established cause of cancer, the report examined the risk factors for weight gain, overweight, obesity. The systematic literature review of this area covered 207 publications investigating the determinants of weight gain, overweight and obesity. The report concludes:

"The epidemiological evidence on physical activity is substantial and consistent. There is robust mechanistic evidence, particularly in relation to its impact on appetite regulation and energy balance. Overall, the evidence that all types of physical activity protect against weight gain, overweight, and obesity is convincing. It has this effect by promoting appropriate energy intake. Conversely, the evidence can be interpreted as showing that sedentary living is a cause of weight gain, overweight, and obesity."​

The panel gives the evidence linking physical activity to a decreased risk of weight gain, overweight and obesity its highest ranking of convincing. The panel ranks the strength of evidence linking energy-dense foods, sugary drinks, and fast food to an increased risk of weight gain, overweight and obesity as probable.

Furthermore, while Siv has claimed that changes to appetite that accompany physical activity cancel the effects of exercise, the report claims otherwise:

"Control [of appetite] seems to be least effective at relatively low levels of physical activity, meaning that sedentary people tend to gain weight more readily than active people. Conversely, although high levels of physical activity increase energy requirements and appetite, the likelihood of consuming more than is needed is lower."​

Therefore, although some may be able to produce studies showing otherwise, the preponderance of high quality scientific evidence strongly supports the assertion that physical activity can prevent weight gain, overweight and obesity.

Since this topic was originally on cancer, I will quote the panel's conclusions about the effects of sugar consumption on the risk for cancer:

"The evidence is hard to interpret. There is limited evidence suggesting that sugar is a cause of colorectal cancer."​

This does not mean that there is convincing evidence that sugar is not a cause of cancer. Rather, the report concludes that there is not sufficient high quality evidence to reach a solid conclusion.

Good post!

 

[Siv]

you know i specifically used that study for appetite suppression.

but if you want something with more significance, try this one: http://www.annals.org/content/140/10/769.full

if you want something really rigid (heavily controlled inpatient vs. outpatient), then this is interesting: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC333231/

You claimed that Atkins weight loss was mostly water loss, so I thought your links would support that. Anyway let's look at what you have now ...

Ok, this is what I have from your first study -

Changes in total body water explained most of the change in fat-free mass in both groups. The expected mean change in total body water was −2.4 kg (CI, −2.9 to −2.0 kg) in the low-carbohydrate diet group and −1.8 kg (CI, −2.3 to −1.3 kg) in the low-fat diet group (mean difference, −0.6 kg [CI, −1.3 to 0 kg]; P = 0.052). However, the low-carbohydrate diet group lost a greater amount of total body water in the first 2 weeks of the study than did the low-fat diet group (−1.1 kg versus −0.5 kg; mean difference, −0.6 kg [CI, −1.0 to −0.2 kg]).

The differences are again very marginal. - 2.4 kg vs 1.8 kg and 1.1 vs 0.6 kg.
Come on, its not even statistically significant, IMO.

And let's look at the actual results from that study, shall we ?

Results: A greater proportion of the low-carbohydrate diet group than the low-fat diet group completed the study (76% vs. 57%; P = 0.02). At 24 weeks, weight loss was greater in the low-carbohydrate diet group than in the low-fat diet group (mean change, −12.9% vs. −6.7%; P < 0.001). Patients in both groups lost substantially more fat mass (change, −9.4 kg with the low-carbohydrate diet vs. −4.8 kg with the low-fat diet) than fat-free mass (change, −3.3 kg vs. −2.4 kg, respectively). Compared with recipients of the low-fat diet, recipients of the low-carbohydrate diet had greater decreases in serum triglyceride levels (change, −0.84 mmol/L vs. −0.31 mmol/L [−74.2 mg/dL vs. −27.9 mg/dL]; P = 0.004) and greater increases in high-density lipoprotein cholesterol levels (0.14 mmol/L vs. −0.04 mmol/L [5.5 mg/dL vs. −1.6 mg/dL]; P < 0.001). Changes in low-density lipoprotein cholesterol level did not differ statistically (0.04 mmol/L [1.6 mg/dL] with the low-carbohydrate diet and −0.19 mmol/L [−7.4 mg/dL] with the low-fat diet; P = 0.2). Minor adverse effects were more frequent in the low-carbohydrate diet group.

Minor adverse effects at the initial stages aside (constipation, headache and the likes), the low carb results were spectacular !

Ok, your second study ... the period is for 50 days total, but in 3 10-day periods. That is very short, IMO. Even 24 weeks in the prev study were short but at least not as short as 50 days. So I don't really find anything significance in the very short term water weight loss.

In any case, the reason for the water loss has also been explained very well b Taubes and others. Carbs make people retain water, as I explained.

 

[Siv]

When studying the effects of various interventions on human health, it is notoriously difficult to glean actionable information from anyone single scientific study. Often these are observational studies that are subject to many confounding factors and limited by small sample sizes, poorly controlled conditions, and short observation periods. Even well-controlled, randomized clinical trials can often reach opposing conclusions.

That is true. But the whole problem with nutrition science (if you can call it science) is how people stretch epidemiological data to support their arguments.
Epidemiological data faces huge problems when it tries to take the place of scientific trials.

Here's an award winning article from Gary Taubes in the National Association of Science Writers on the limitations of epidemiology.
http://www.nasw.org/awards/1996/96Taubesarticle.htm

We can reach better conclusions, however, by performing a systematic literature review: examining the scientific literature as a whole by using strict criteria to select the highest quality studies and evaluating the results of the all of the studies as a whole. Although there may be individual studies within the review that support either side of an assertion, if a large majority of the studies support one side of an argument, we can be much more confident about their conclusions.

The 2007 report, Food, Nutrition, Physical Activity, and the Prevention of Cancer by the World Cancer Research Fund and American Institute for Cancer Research does just this. I will summarize the relevant findings of the review below. The full report is available here: http://www.dietandcancerreport.org/

Problem again, is that it is an epidemiological report. A meta analysis, but one based on epidemiological data nonetheless.

Therefore, although some may be able to produce studies showing otherwise, the preponderance of high quality scientific evidence strongly supports the assertion that physical activity can prevent weight gain, overweight and obesity.

High quality evidence ? No.
I will go through the link in detail later when I have time.

Meanwhile, people who have tried to actual clinical trials find quite the opposite results.

Dr. Timothy Church for eg.
At http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004515

This was a 6 month study. But the surprising finding was that, the control group had a better outcome than the high exercise group

The primary finding from this large exercise intervention trial in postmenopausal women is that the difference between actual weight loss and predicted weight loss (compensation) increases with exercise dose. We confirmed the findings of previous studies that a relatively high dose of exercise (12 KKW or 194 minutes per week) results in compensatory mechanisms that attenuate weight loss in previously sedentary women. However, a dose of exercise consistent with the exercise prescription for general health (8 KKW or 136 minutes per week) did not result in compensation as the actual weight loss closely matched the predicted weight loss. An exercise dose of 4 KKW (72 minutes per week) also resulted in weight loss that slightly exceeded the predicted weight loss. Our findings are important because most exercise guidelines for weight loss recommend 200–300 minutes per week and we provide evidence that this amount of exercise induces compensation that results in significantly less weight loss than predicted.

So 10-15 mins exercise per day (the most sedentary of the 3 groups) seems the most beneficial !

Please also see the Terry Wilkin study re: childhood obesity that I posted earlier.
http://adc.bmj.com/content/early/200...35012.abstract
There were no associations between physical activity and changes in any measure of body mass or fatness over time in either sex (e.g. BMI-SDS: r=-0.02 p=0.76). However, there was a small-to-moderate inverse association between physical activity and change in composite metabolic score (r=-0.19, p<0.01). Mixed effects modeling showed that the improvement in metabolic score among the more active compared to the less active children was linear with time (-0.08 z-scores/year, p=0.001). Again, this is an actual trial, not an epidemiological analysis.

Other studies are mentioned in this article
http://www.cbc.ca/health/story/2009/05/07/school-exercise-obesity-child.html

Rather than relying on epidemiological evidence, if you end up doing actual studies, however faulty they may be, the results are far more accurate and practical.

Blaming our sedentary lifestyles for obesity without any actual evidence is something for which Jean Mayer requires the most credit. And he promoted his pro-exercise message with a religious zeal like a moral crusade.

People are exercising far more today than they did several decades ago. So, has the obesity declined or gone up ?!

 

[bobze]

That is true. But the whole problem with nutrition science (if you can call it science) is how people stretch epidemiological data to support their arguments.
Epidemiological data faces huge problems when it tries to take the place of scientific trials.

Here's an award winning article from Gary Taubes in the National Association of Science Writers on the limitations of epidemiology.
http://www.nasw.org/awards/1996/96Taubesarticle.htm

Problem again, is that it is an epidemiological report. A meta analysis, but one based on epidemiological data nonetheless.

High quality evidence ? No.
I will go through the link in detail later when I have time.

Meanwhile, people who have tried to actual clinical trials find quite the opposite results.

Dr. Timothy Church for eg.
At http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004515

This was a 6 month study. But the surprising finding was that, the control group had a better outcome than the high exercise group
So 10-15 mins exercise per day (the most sedentary of the 3 groups) seems the most beneficial !

Please also see the Terry Wilkin study re: childhood obesity that I posted earlier.
http://adc.bmj.com/content/early/200...35012.abstract
There were no associations between physical activity and changes in any measure of body mass or fatness over time in either sex (e.g. BMI-SDS: r=-0.02 p=0.76). However, there was a small-to-moderate inverse association between physical activity and change in composite metabolic score (r=-0.19, p<0.01). Mixed effects modeling showed that the improvement in metabolic score among the more active compared to the less active children was linear with time (-0.08 z-scores/year, p=0.001). Again, this is an actual trial, not an epidemiological analysis.

Other studies are mentioned in this article
http://www.cbc.ca/health/story/2009/05/07/school-exercise-obesity-child.html

Rather than relying on epidemiological evidence, if you end up doing actual studies, however faulty they may be, the results are far more accurate and practical.

Blaming our sedentary lifestyles for obesity without any actual evidence is something for which Jean Mayer requires the most credit. And he promoted his pro-exercise message with a religious zeal like a moral crusade.

People are exercising far more today than they did several decades ago. So, has the obesity declined or gone up ?!

3 quick points because I'm running late. Firstly, as Ygg pointed out Systematic/Meta-Reviews>>>>>> case-controls, cohorts or any other primary literature findings. Because, systematic reviews offer to us a summation of findings from many different sources, we are able to derive trends in them. As Ygg's review also points out that trend is to show that when you exercise a long with watching your diet you lose weight.

Secondly to your underlined sentence above. Many people do exercise more, however people also eat larger meal portions than they did in say the 50's or 60's. A serving of meat for most people should be about a deck of cards, when was the last time in America you've seen a correct portion of meat on the menu? Being a medical student, I eat out a lot--Restaurants take the "American dream" (more for less) approach to advertising. In fact, that approach to advertising is everywhere around us in the food industry--"More for less".

And finally, can you propose a biochemical mechanism whereby different types of carbohydrates are preferentially stored as fat? Without being able to show this any evidence of differential carb storage is anecdotal and more likely attributed to confounding factors (even if the confounder is a food specific factor, for example something else in the food with those "bad" carbs which promotes more fat storage)Thanks

Edit: Your BMJ link isn't working by the way.

 

[Siv]

3 quick points because I'm running late. Firstly, as Ygg pointed out Systematic/Meta-Reviews>>>>>> case-controls, cohorts or any other primary literature findings. Because, systematic reviews offer to us a summation of findings from many different sources, we are able to derive trends in them. As Ygg's review also points out that trend is to show that when you exercise a long with watching your diet you lose weight.

Unfortunately, whether its one study or a meta analysis, if its epidemeliogical data, its pretty much often always misleading. Did you read the link I posted with Taubes award winning article on that ?

And finally, can you propose a biochemical mechanism whereby different types of carbohydrates are preferentially stored as fat? Without being able to show this any evidence of differential carb storage is anecdotal and more likely attributed to confounding factors (even if the confounder is a food specific factor, for example something else in the food with those "bad" carbs which promotes more fat storage)

Its been beautifully explained, by Taubes and others. Carbs drive insulin drive fat storage (and other bad things). Read the book, its hard for me to summarize an entire book with tons of studies into one post. As I was telling someone else on this forum, the book is like pubmed, so its hard reading. But the plethora of evidence is worth it.

Your BMJ link isn't working by the way.

Oops, sorry. It was working yesterday. Let me check.

 

[mtc1973]

Not sure why there seems to be so much sure footed posturing in this thread. Obesity - is evidently a spectrum disorder - not a single disease. And as a spectrum disorder will have a spectrum of causes. Until we are in a position to ascribe the different causes of obesity to their respective populations - none of these studies will be in a position to make specific claims. All that remains is statistical correlation and postulation.

 

[Proton Soup]

Not sure why there seems to be so much sure footed posturing in this thread. Obesity - is evidently a spectrum disorder - not a single disease. And as a spectrum disorder will have a spectrum of causes. Until we are in a position to ascribe the different causes of obesity to their respective populations - none of these studies will be in a position to make specific claims. All that remains is statistical correlation and postulation.

i suppose you could make the same argument about alcoholism and drug use, but it's not helpful for explaining what is going on in the majority of the population. it's really just excuse-making for a population whose primary problem is they enjoy continuing their behavior more than they dislike the negative side effects.

the really interesting thing about this "disease" of obesity is that if you take away their freedoms and only allow them to consume a healthy amount of calories, they will lose weight.

 

[Proton Soup]

You claimed that Atkins weight loss was mostly water loss, so I thought your links would support that. Anyway let's look at what you have now ...

Ok, this is what I have from your first study - The differences are again very marginal. - 2.4 kg vs 1.8 kg and 1.1 vs 0.6 kg.
Come on, its not even statistically significant, IMO.

And let's look at the actual results from that study, shall we ? Minor adverse effects at the initial stages aside (constipation, headache and the likes), the low carb results were spectacular !

Ok, your second study ... the period is for 50 days total, but in 3 10-day periods. That is very short, IMO. Even 24 weeks in the prev study were short but at least not as short as 50 days. So I don't really find anything significance in the very short term water weight loss.

In any case, the reason for the water loss has also been explained very well b Taubes and others. Carbs make people retain water, as I explained.

where did you explain that carbs make people retain water?

and yes, low-carb diets (temporary diets for fat reduction(my fave would be the protein-sparing modified fast, with almost no fat at all)) can be spectacular for a number of reasons. as mentioned before, ketosis can have a significant appetite-suppressive effect, and this makes it easier for people stay on the diet. it also makes it easier for them to control their intake and consume fewer calories. and that is the important point I'm trying to get across. there is nothing magical about carbs making you fat, it's an excess of calories consumed that makes you fat.

and look again at the inpatient study. i think what you will see is that when you actually control what people eat (they can't cheat by sneaking candy and lying about it - skewing your results), fat loss on either a low or med. carb diet is similar.

the other thing to remember is that these studies are primarily about dieting for fat loss, and really don't make a case for eating a ketotic diet on a chronic basis. for that, go look up the papers where they mention the problems with keeping epilepsy patients on keto diets.

 

[mtc1973]

Agree totally Proton - its the only approach that works. I just find it strange that people want to ascribe it to all these different specific things - what's the point. We don't know - but as you say - what we do know is that if you limit intake and expend more energy - its a solution - irresepective of the specifics of the problem.

Of course people don't want to hear that because it means that they can control the problem - it just takes a heck of a lot of effort and fighting against what our evolutionary biology has dictated we do! In a world of scarcity it was wise to crave fatty sugary food! The scenario has changed!

Manufacturers also don't want to hear it because they can't make money out of people by selling supplements, plans, pills etc

I always am amazed at the amount of money spent on diabetes and CV research - when in fact if we changed attitudes at a young age - we could prevent themajority of these diseases even occurring. Prevention is ultimate, cure is an expensive band aid.

 

[bobze]

Unfortunately, whether its one study or a meta analysis, if its epidemeliogical data, its pretty much often always misleading. Did you read the link I posted with Taubes award winning article on that ?

Its been beautifully explained, by Taubes and others. Carbs drive insulin drive fat storage (and other bad things). Read the book, its hard for me to summarize an entire book with tons of studies into one post. As I was telling someone else on this forum, the book is like pubmed, so its hard reading. But the plethora of evidence is worth it.

Oops, sorry. It was working yesterday. Let me check.

No I don't mean how carbohydrates drive insulin regulation and vise-versa. I'm well versed in that.

However, you claimed that various types of carbohydrates promoted this more than others, if I'm remembering correctly (a couple pages back I believe).

What I was asking for is, what is the biochemical mechanism or hypothesis that would explain this. Otherwise, as I pointed out, its just as likely that other confounding factors associated with those 'types of carbs' are the culprit in the up-regulation of insulin and not the 'type' of carb itself.

For example. You claimed that HFCS (a mix of fructose and glucose) is 'worse' for you than sucrose (fructose and glucose). What is the proposed biochemical mechanism for this? And on what basis do you discard the hypothesis that foods with HFCS may contain another factor that promotes obesity over sucrose based ones (if it does at all)?

 

[Ygggdrasil]

That is true. But the whole problem with nutrition science (if you can call it science) is how people stretch epidemiological data to support their arguments.
Epidemiological data faces huge problems when it tries to take the place of scientific trials.

Here's an award winning article from Gary Taubes in the National Association of Science Writers on the limitations of epidemiology.
http://www.nasw.org/awards/1996/96Taubesarticle.htm

Problem again, is that it is an epidemiological report. A meta analysis, but one based on epidemiological data nonetheless.

You would have a valid point if the report relied solely on epidemiologial evidence. But, it does not. Of the studies considered linking physical activity to weight maintenance and change, the panel considered 17 randomized controlled trials versus 62 consort studies. No doubt, the experts on the panel gave more consideration to the randomized trials than the consort studies.

For example, we can consider the studies that examined the effects of total physical activity on weight maintenance and change in adults. In this category, there were three randomized controlled trials and 16 consort studies. Two of the randomized controlled trials showed positive effects of physical activities while one of the trials showed no effect. All of the 16 consort studies in this area showed a positive effect. The citations for the three randomized trials are below:

• Schmitz KH, Jensen MD, Kugler KC, et al. Strength training for obesity prevention in midlife women. Int J Obes 2003;27:326-33.
• Borg P, Kukkonen-Harjula K, Fogelholm M, et al. Effects of walking or resistance training on weight loss maintenance in obese, middle-aged men: a randomized trial. Int J Obes 2002;26:676-83.
• Fogelholm M, Kukkonen-Harjula K, Nenonen A, et al. Effects of walking training on weight maintenance after a very-low-energy diet in premenopausal obese women: a randomized controlled trial. Arch Intern Med 2000;160:2177-84.

As I said before, some studies will show no effect and some studies will show a positive effect. However, considering the evidence as a whole shows that the bulk of the evidence points to physical activity as a protective factor against weight gain.

Meanwhile, people who have tried to actual clinical trials find quite the opposite results.

Dr. Timothy Church for eg.
At http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004515

This was a 6 month study. But the surprising finding was that, the control group had a better outcome than the high exercise group
So 10-15 mins exercise per day (the most sedentary of the 3 groups) seems the most beneficial !

I'm not so sure you're reading the study correctly. Look at at the data in http://www.plosone.org/article/showImageLarge.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0004515.g003&representation=PNG_L . While the control group showed a weight change of -0.9 kg, the 4 kcal/kg/week exercise group showed a weight change of -1.4 kg, the 8 kcal/kg/week exercise group showed a weight change of -2.1 kg, and the 12 kcal/kg/week exercise group showed a weight change of -1.5 kcal/kg/week. All three experimental groups showed more weight loss than the control group. The authors are merely saying that as exercise dose increases, you get decreasing returns on weight loss (due to the compensatory increases in appetite that you discussed earlier). However, this compensation does not lead to any of the exercise groups to show less weight loss than the control group.

 

[Siv]

Ok, read this news article yesterday.
http://www.dailymail.co.uk/health/a...-diet-make-live-longer.html?ito=feeds-newsxml
Can cutting carbohydrates from your diet make you live longer?

Professor Cynthia Kenyon, whom many experts believe should win the Nobel Prize for her research into ageing, has discovered that the carbohydrates we eat — from bananas and potatoes to bread, pasta, biscuits and cakes — directly affect two key genes that govern youthfulness and longevity.

Scientists already knew how to make laboratory animals live longer and healthier lives — you just cut back their calories to about three-quarters of their normal amount.

It’s not a practical solution for humans, because you feel cold and hungry all the time.

But what Professor Kenyon found out was why *drastically reducing calories has such a remarkable effect.

She discovered that it changed the way two crucial genes behaved. It turned down the gene that controls insulin, which in turn switched on another gene, which in turn switched on another gene, which acted like an elixir of life.

We jokingly called the first gene the Grim Reaper because when it’s switched on, the lifespan is fairly short,’ she explains.

Discovering the Grim Reaper gene has prompted the professor to *dramatically alter her own diet, *cutting right back on carbohydrates. That’s because carbs make your body produce more insulin (to mop up the extra blood sugar carbs *produce); and more insulin means a more active Grim Reaper.

One clue came from a small remote community of dwarves living in northern Ecuador who are cancer-free. They are missing the part of the Grim Reaper gene that controls a hormone called insulin-like growth factor. The downside is they only grow to 4ft tall because the hormone is needed for growth.

But this missing bit of the Grim Reaper gene also means they don’t develop cancer and are less likely to suffer from heart disease or obesity.

Professor Jeff Holly, who specialises in insulin-like growth factor, confirms that it is linked to cancer of the prostate, breast and colon.

In fact raised insulin levels, triggered by high carbohydrate *consumption, could be what *connects many of our big killers.

One way to reduce insulin levels is to exercise, which makes you more sensitive to it, which in turn means you need less of it. It also gives another health benefit in a surprising way. Exercise actually increases the level of damaging free radicals which stimulates the body to produce more protective anti-oxidants.

So should we all be trying to cut back on carbs to reduce our insulin levels?

It is a suggestion that flies in the face of 30 years of health advice to have a lower fat intake and eat plenty of long-lasting complex carbo*hydrates to keep the body supplied with energy.

 

[Siv]

For example, we can consider the studies that examined the effects of total physical activity on weight maintenance and change in adults. In this category, there were three randomized controlled trials and 16 consort studies. Two of the randomized controlled trials showed positive effects of physical activities while one of the trials showed no effect. All of the 16 consort studies in this area showed a positive effect. The citations for the three randomized trials are below:

• Schmitz KH, Jensen MD, Kugler KC, et al. Strength training for obesity prevention in midlife women. Int J Obes 2003;27:326-33.
• Borg P, Kukkonen-Harjula K, Fogelholm M, et al. Effects of walking or resistance training on weight loss maintenance in obese, middle-aged men: a randomized trial. Int J Obes 2002;26:676-83.
• Fogelholm M, Kukkonen-Harjula K, Nenonen A, et al. Effects of walking training on weight maintenance after a very-low-energy diet in premenopausal obese women: a randomized controlled trial. Arch Intern Med 2000;160:2177-84.

As I said before, some studies will show no effect and some studies will show a positive effect. However, considering the evidence as a whole shows that the bulk of the evidence points to physical activity as a protective factor against weight gain.

Hmm. Exercise definitely has other benefits and I have admitted that. It improves your insulin resistance, among other things, which could definitely help you reduce weight.
What I don't believe, and what I don't think there is evidence for is the simplistic calories in calories out interpretation of saying that the more you exercise, the more calories out and therefore you will lose weight. Thats nonsense. Because the body will compensate by making you hungrier. We have evolved a very complicated system over millions of years to preserve homeostasis.

I'm not so sure you're reading the study correctly. Look at at the data in http://www.plosone.org/article/showImageLarge.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0004515.g003&representation=PNG_L . While the control group showed a weight change of -0.9 kg, the 4 kcal/kg/week exercise group showed a weight change of -1.4 kg, the 8 kcal/kg/week exercise group showed a weight change of -2.1 kg, and the 12 kcal/kg/week exercise group showed a weight change of -1.5 kcal/kg/week. All three experimental groups showed more weight loss than the control group. The authors are merely saying that as exercise dose increases, you get decreasing returns on weight loss (due to the compensatory increases in appetite that you discussed earlier). However, this compensation does not lead to any of the exercise groups to show less weight loss than the control group.

Here's the chart
There is a marginal reduction, I agree. But its marginal.
And the more the intensity increases the lesser it is. Which kind of negates the simplistic calories in calories out theory.
Plus how are you controlling for the other improvements due to exercise, like insulin resistance ?

Have you read this article from Gary Taubes ? You don't seem the kind of person who dismisses folks without reading the evidence, so please do read it.
http://nymag.com/news/sports/38001/
There is other evidence too, let me try and dig it out. Wish I had more time.

 

[Siv]

No I don't mean how carbohydrates drive insulin regulation and vise-versa. I'm well versed in that.

Great. So you do realize the truth in that.

However, you claimed that various types of carbohydrates promoted this more than others, if I'm remembering correctly (a couple pages back I believe).

What I was asking for is, what is the biochemical mechanism or hypothesis that would explain this. Otherwise, as I pointed out, its just as likely that other confounding factors associated with those 'types of carbs' are the culprit in the up-regulation of insulin and not the 'type' of carb itself.

For example. You claimed that HFCS (a mix of fructose and glucose) is 'worse' for you than sucrose (fructose and glucose). What is the proposed biochemical mechanism for this? And on what basis do you discard the hypothesis that foods with HFCS may contain another factor that promotes obesity over sucrose based ones (if it does at all)?

Here are my posts. They present what I said and some of the studies. Please read them.
https://www.physicsforums.com/showpost.php?p=2948044&postcount=17
https://www.physicsforums.com/showpost.php?p=2941054&postcount=2
https://www.physicsforums.com/showpost.php?p=2943978&postcount=13

 

[Ygggdrasil]

Hmm. Exercise definitely has other benefits and I have admitted that. It improves your insulin resistance, among other things, which could definitely help you reduce weight.
What I don't believe, and what I don't think there is evidence for is the simplistic calories in calories out interpretation of saying that the more you exercise, the more calories out and therefore you will lose weight. Thats nonsense. Because the body will compensate by making you hungrier. We have evolved a very complicated system over millions of years to preserve homeostasis.

It is certainly true that strong homeostatic mechanisms regulate weight gain in humans. Perhaps strengthening this homeostasis through exercise provides much of its protection against weight gain. However, it is also true that this homeostatic system evolved under conditions where humans were much more physically active than modern humans. All homeostatic systems have limits and it is plausible that at very low levels of physical activity the homeostatic system does not work so well. If this is the case, increases in physical activity from very low levels to moderate levels could have some positive effect. But, this is speculation.

Although the World Cancer Research Fund study shows that physical activity is protective against weight gain, it does not delve deeply into the mechanisms behind the protective effect. They do cite some evidence suggesting that the increased insulin sensitivity from regular physical activity may play a role. So, you certainly could be right that the positive effects of exercise on weight maintenance are not primarily due to the increased energy expenditure due to physical activity. Certainly the Church study shows that compensatory effects do exist. Whether the simple calorie in/calorie out explanation or some other explanation mediates the protective effect of exercise is an a question that probably requires further study.

Have you read this article from Gary Taubes ? You don't seem the kind of person who dismisses folks without reading the evidence, so please do read it.
http://nymag.com/news/sports/38001/
There is other evidence too, let me try and dig it out. Wish I had more time.

I agree with the general point of the article: exercise alone will not help one lose weight. Controlling one's diet is another important factor and can often be more important than exercising. If the sole goal is weight loss, exercise may not be the most important factor (although I haven't seen any good evidence yet showing that it hurts weight loss as suggested by the article). Consistent with this view, the WCRF report cites many randomized controlled trials that show that a combination of physical activity and dietary interventions are effective at promoting weight loss.

Finally, the fact remains that strong scientific evidence demonstrates that exercise helps to maintain body weight and protects against weight gain as well as other diseases like diabetes, cancer, and heart disease. Even though regular physical activity may not promote weight loss as well as people think, there are still many good reasons to exercise regularly. Exercise may not necessarily make one thinner, but it will certainly make one healthier.

 

[Siv]

Very well written, Ygggdrasil.
While you and I may differ on some points, overall I think I agree with what you say.

 

[Proton Soup]

Ok, read this news article yesterday.
http://www.dailymail.co.uk/health/a...-diet-make-live-longer.html?ito=feeds-newsxml
Can cutting carbohydrates from your diet make you live longer?

i certainly have doubts about much of it. we're certainly not worms or lab rats. very little of the stuff that works in rats re obesity pans out in humans, fwiw.

some things are fairly obvious. kids are eating a bit too much and not exercising as much now. this tends to accelerate some things physiologically, like puberty. it will be interesting to see how that pans out (after I'm dead and gone, most likely), but I'm guessing it shortens their lifespan. being obese is bad, there's not much controversy there.

the other side of the coin is to presumably increase lifespan by decreasing caloric intake, perhaps even below what used to be considered normal. you probably don't want to do this in children and adolescents, especially females. one obvious problem is that most women are prone to osteoporosis in old age, and by age 30, they've got all the calcium they will ever have in their bones. from there it is all downhill. both diet and exercise are important here, as exercise will provide hormonal stimulus to build stronger bones.

later in life, you run into other things. elderly people actually have a better life expectancy if there is a little bit of chub on them. and as always, being too obese will never help, but that typical J-shaped curve(if you're underweight, mortality goes up, overweight and mortality goes up) for longevity shifts to the right a bit.

in general, it seems that optimum BMI is neither too high, nor too low, and optimum may vary by life stage.

and there are other things. for one, we humans don't seem well-designed for conserving calories. we seem designed for keeping our big brains alive, generating copious amounts of heat. we also seem well-designed for traversing long distances on foot, wearing down lesser animals with not speed, but sheer persistance. both of these functions demand copious and efficient fat storage. and come with the expectation that there will be intermittent periods of starvation.


another idea i'd like to throw out there (and i think this is a fairly new topic of research, so there isn't a mountain of data yet) is the http://www.ncbi.nlm.nih.gov/pubmed/15836464" .

 

[mtc1973]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2491496/?tool=pubmed

I love this mouse! I read about it a few years back - but he shows some definite and drastic changes in phenotype in response to a single gene overexpression in a place where it usually ain't! Put a liver enzyme in skeletal muscle - change how the muscle is fuelled - and watch him go! It's pretty amazing.

As usual - its a mouse - so I aint saying anything about the human condition - but its very interesting nevertheless.

 

[hamster143]

Ok, read this news article yesterday.
http://www.dailymail.co.uk/health/a...-diet-make-live-longer.html?ito=feeds-newsxml
Can cutting carbohydrates from your diet make you live longer?

There is an obvious question that arises after reading this article.

Your body needs energy. This energy can come from carbs, fat or protein. Regardless of the source, the only way the energy can get to your internal organs is via blood glucose. Insulin is released by the pancreas in response to blood glucose. Even if your diet is 100% fat, that fat is converted into glucose via ketogenesis/gluconeogenesis before the energy can be used.

What reason is there to think that consuming 2000 calories/day of "slow release" complex carbs will result in significantly different levels of insulin from consuming the same 2000 calories/day of fat and protein?

 

[Siv]

There is an obvious question that arises after reading this article.

Your body needs energy. This energy can come from carbs, fat or protein. Regardless of the source, the only way the energy can get to your internal organs is via blood glucose. Insulin is released by the pancreas in response to blood glucose. Even if your diet is 100% fat, that fat is converted into glucose via ketogenesis/gluconeogenesis before the energy can be used.

I am no biochemistry expert (Dr. Stephan Guyenet is, BTW) but here's what it says from everyone's favourite source - wiki -

Most advocates of low-carbohydrate diets, such as the Atkins Diet, argue that the human body is adapted to function primarily in ketosis.[62][63] They argue that high insulin levels can cause many health problems, most significantly fat storage and weight gain. They argue that the purported dangers of ketosis are unsubstantiated (some of the arguments against ketosis result from confusion between ketosis and ketoacidosis which is a related and very dangerous condition).[64] They also argue that fat in the diet only contributes to heart disease in the presence of high insulin levels and that if the diet is instead adjusted to induce ketosis, fat and cholesterol in the diet are not a major concern (although most do not advocate unrestricted fat intake and do advocate avoiding trans fat).

On a high-carbohydrate diet, glucose is used by cells in the body for the energy needed for their basic functions, and about 2/3 of body cells require insulin in order to use glucose. Excessive amounts of blood glucose are thought to be a primary cause of the complications of diabetes; when glucose reacts with body proteins (resulting in glycosolated proteins) and change their behavior. Perhaps for this reason, the amount of glucose tightly maintained in the blood is quite low. Unless a meal is very low in starches and sugars, blood glucose will rise for a period of an hour or two after a meal. When this occurs, beta cells in the pancreas release insulin to cause uptake of glucose into cells. In liver and muscle cells, more glucose is taken in than is needed and stored as glycogen (once called 'animal starch').[65] Diets with a high starch/sugar content, therefore, cause release of more insulin and so more cell absorption. In diabetics, glucose levels vary in time with meals and vary a little more as a result of high carbohydrate content meals. In non-diabetics, blood sugar levels are restored to normal levels within an hour or two, regardless of the content of a meal.

It is worth noting that while there are Essential Fatty Acids(EFA) and Essential Amino Acids(EAA) there are no essential carbohydrates of any sort and while a diet devoid of EFA or EAA will result in eventual death, a diet completely without carbohydrates can be maintained indefinitely without health detriment.

What reason is there to think that consuming 2000 calories/day of "slow release" complex carbs will result in significantly different levels of insulin from consuming the same 2000 calories/day of fat and protein?

I guess no other reason than the fact that it does. Have you measured your insulin and blood glucose levels after a mostly fatty meal ? People have. My mom has (she is a diabetic). If you add carbs, the difference is marked.

 

[cosmos 2.0]

I am no biochemistry expert (Dr. Stephan Guyenet is, BTW) but here's what it says from everyone's favourite source - wiki -

On a high-carbohydrate diet, glucose is used by cells in the body for the energy needed for their basic functions, and about 2/3 of body cells require insulin in order to use glucose. Excessive amounts of blood glucose are thought to be a primary cause of the complications of diabetes; when glucose reacts with body proteins (resulting in glycosolated proteins) and change their behavior. Perhaps for this reason, the amount of glucose tightly maintained in the blood is quite low. Unless a meal is very low in starches and sugars, blood glucose will rise for a period of an hour or two after a meal. When this occurs, beta cells in the pancreas release insulin to cause uptake of glucose into cells. In liver and muscle cells, more glucose is taken in than is needed and stored as glycogen (once called 'animal starch').[65] Diets with a high starch/sugar content, therefore, cause release of more insulin and so more cell absorption. In diabetics, glucose levels vary in time with meals and vary a little more as a result of high carbohydrate content meals. In non-diabetics, blood sugar levels are restored to normal levels within an hour or two, regardless of the content of a meal.

while i agree with this , it should be kept in mind this is normal mechanism in the body. People have tendency to eat excess carbohydrates mostly refined carbs, the body is given a new challenge to tackle this excess carbs. The normal mechanism is to secrete insulin which makes the cells in the body to take up the glucose and rest to store in liver as glycogen. what happens when we constantly take this excess carbs in the diet along with a sedentary lifestyle, is why the body has to adjust and undergo physiological changes like conversion of excess carbs into fat stored in body. The excess carbs also leads to increased insulin secretion which becomes limited or exhausted in the sense that it cannot be produced more after it reaches a certain level.

What reason is there to think that consuming 2000 calories/day of "slow release" complex carbs will result in significantly different levels of insulin from consuming the same 2000 calories/day of fat and protein?

I would like to see studies where calories got from fat and protein is better than calories from slow release complex carbohydrates, otherwise it only becomes an assumption.

 

[cosmos 2.0]

It is worth noting that while there are Essential Fatty Acids(EFA) and Essential Amino Acids(EAA) there are no essential carbohydrates of any sort and while a diet devoid of EFA or EAA will result in eventual death, a diet completely without carbohydrates can be maintained indefinitely without health detriment.

There are various types of fats and all are not essential for our body except linoleic acid,omega 3 fatty acids.

http://en.wikipedia.org/wiki/Essential_fatty_acid" No nobody is going to die if they don't eat carbs, carbohydrates are the easiest and most usable fuel in the body.

Proteins and fat are essential , but they are not easily used in the body - that is why the term ketosis usually arises whenever atkin's type of diet is suggested.

Most advocates of low-carbohydrate diets, such as the Atkins Diet, argue that the human body is adapted to function primarily in ketosis.[62][63] They argue that high insulin levels can cause many health problems, most significantly fat storage and weight gain. They argue that the purported dangers of ketosis are unsubstantiated (some of the arguments against ketosis result from confusion between ketosis and ketoacidosis which is a related and very dangerous condition).[64] They also argue that fat in the diet only contributes to heart disease in the presence of high insulin levels and that if the diet is instead adjusted to induce ketosis, fat and cholesterol in the diet are not a major concern (although most do not advocate unrestricted fat intake and do advocate avoiding trans fat).

what are long term effects of high protein and fat diet ? These studies are limited. Yes, better outcomes are seen, as some studies have indicated with regards to low carb diet.
Also there is a tendency to avoid foods such as vegetables and fruits even though they contain nutrients and fiber because they have carbs.

Not all fats are good. Trans fats are bad. Even proteins, high amount of red meat intake is associated with heart diseases , cancers .

http://en.wikipedia.org/wiki/Red_meat"

 

[hamster143]

I guess no other reason than the fact that it does. Have you measured your insulin and blood glucose levels after a mostly fatty meal ? People have. My mom has (she is a diabetic). If you add carbs, the difference is marked.

I found this article

http://www.ajcn.org/cgi/content/abs...INDEX=0&sortspec=relevance&resourcetype=HWCIT

Things are not as simple as one might think. Beef produces higher insulin response per calorie than pasta, and white bread produces more response than apples... And I bet there are some nonlinear effects too, e.g. eating twice the amount of food more than doubles the insulin response in the short term (though what happens to the integrated response, no one knows).

And I'm 99% sure that your mom has not measured her insulin levels after different kinds of meals. Glucose yes, insulin no. There are simply no commercially available blood insulin level meters on the market.

 

[miami]

The success rate of diet pills is very low and they seem to be a perfect recipe for self destruction as they can apparently cause heart attacks, strokes and numerous other major health problems.

When you peruse the link below you will be absolutely astounded (as I was) and you will probably wonder why diet pills were not banned a long time ago.

 

[Siv]

I would like to see studies where calories got from fat and protein is better than calories from slow release complex carbohydrates, otherwise it only becomes an assumption.

Studies? You have a whole big fat book, called Good Calories, Bad Calories. And its a very dry read, because it has pages and pages and pages of data and studies, plus of course tons of references.

And that's not the only book, there are many others.

 

[Siv]

And I'm 99% sure that your mom has not measured her insulin levels after different kinds of meals. Glucose yes, insulin no. There are simply no commercially available blood insulin level meters on the market.

Yes, my mom has measured her insulin on three occasions (not at home, in the hospital). The insulin response of an egg meal was significantly lower than a fruit one. Rice and lentils was high, a bit higher than the fruit meal, in fact.

From this link < http://www.ajcn.org/cgi/content/full/90/4/986 >
" Interestingly, in the present study, the fat content of the mixed meal showed a significant inverse relation (r = –0.60) with observed insulin responses and was a more reliable predictor of insulin demand than the amount of carbohydrate. "

This is standard, actually. Everyone knows that fat results in very low rises in blood sugar and insulin, and yet diabetics are told to reduce their fat. The standard myth being that fat is calorie dense and also that fat can cause CVD and CHD. Saturated fat esp, has been given a terrible reputation, which is totally undeserved.

http://www.ajcn.org/cgi/content/full/80/5/1102
http://www.ajcn.org/cgi/content/full/80/5/1175
http://atvb.ahajournals.org/cgi/content/full/24/3/498

And the best of all, a nice paper from Nutrition journal, which summarizes all the myths and how useless nutrition science really is today.

http://www.nutritionjrnl.com/article/PIIS0899900710002893/fulltext

I love the Summary. A bit long but worth reading.

Summary: What can be done?
Is there nothing of value in the DGAC Report? On the contrary, there are valuable suggestions made regarding improving nutritional literacy and cooking skills; restructuring the food environment, including farmers, agricultural producers, and food manufacturers; and improving the availability of affordable fresh produce. However, none of these recommendations makes sense in the context of nutritional guidance that is not based on sound scientific principles and demonstrable results. Reforming the food environment must begin with a re-evaluation of 30 y of nutritional policy that was originally implemented without a thorough and unbiased evaluation of the science.

It is of interest to consider the opinion of the American Medical Association (AMA) with respect to the first implementation of dietary guidelines [80]. In an editorial, it was stated:

We believe that it would be inappropriate at this time to adopt proposed national dietary goals as set forth in the Report on Dietary Goals for the United States. The evidence for assuming that benefits to be derived from the adoption of such universal dietary goals as set forth in the Report is not conclusive and there is potential for harmful effects from a radical long-term dietary change as would occur through adoption of the proposed national goals.

The guidelines recommended at that time show great similarity to the current recommendations:

The Report sets forth six dietary goals of the United States. These goals are as follows:


1.Increased carbohydrate consumption to account for 55% to 60% of energy (caloric) intake.


2.Reduce overall fat consumption from approximately 40% to 30% of energy intake.


3.Reduce saturated fat consumption to account for about 10% of total energy intake; and balance that with polyunsaturated and monounsaturated fats, which should account for about 10% of energy intake.


4.Reduce cholesterol consumption to about 300 mg/day.


5.Reduce sugar consumption by about 40% to account for about 15% total energy intake.


6.Reduce salt consumption by 50% to 85% to approximately 3 gm/day

In the three decades since, carbohydrate consumption has increased; overall fat, saturated fat, and cholesterol consumption have decreased to near or below targeted levels; caloric intake remains within recommended levels; and leisure-time physical activity has increased slightly (pp. D1-1, D3-10, B2-3). At the same time, scientific evidence in favor of these recommendations remains inconclusive, and we must consider the possibility that the “potential for harmful effects” has in fact been realized. Notably, “the prevalence of overweight and obesity in the US has increased dramatically in the past three decades” (A4); the number of Americans diagnosed with T2D has tripled [81].

The AMA concludes:

The Report suggests that the incidence of heart disease, cancer, hypertension, diabetes, obesity and tooth decay could be reduced by making qualitative and quantitative changes in “the American diet.” The goals are laudable; however, the American Medical Association believes that there are insufficient data to recommend such changes in the diet on a nationwide scale.

Laudable as the goals were, the application of those recommendations has constituted a population-wide dietary experiment that should be brought to a halt. Lack of supporting evidence limits the value of the proposed recommendations as guidance for the consumer or as the basis of public health policy. We ask whether the Dietary Guidelines for Americans process as it stands should continue or whether there might not be better alternatives.

It is time for public health leaders, scientists, and clinicians to stop blaming Americans for not following the recommendations in the Dietary Guidelines for Americans and instead to re-examine the process used to formulate the US dietary guidelines and determine whether or not it is still appropriate for our current needs.

We ask whether it would be preferable to convene an impartial panel of scientists consisting of biochemists, anthropologists, geneticists, physicists, etc., who are not directly tied to nutritional policy. Such a panel would be able to hear all sides in the debate with few preconceived notions. Recommendations issued by this group would be more likely to be moderate, circumspect, and established on a complete and accurate assessment of available science rather than a narrow perspective of accepted nutritional practice. Public health nutritional policies produced from such recommendations may then serve the honorable intentions of those first dietary goals “to maximize the quality of life for all Americans” [5].

 

[hamster143]

The insulin response of an egg meal was significantly lower than a fruit one.

The immediate response, maybe. After a fruit meal, insulin levels drop down to fasting levels within 2 hours. An egg meal may take much longer to absorb completely.

Everyone knows that fat results in very low rises in blood sugar and insulin,

not just fat, but presence of fat. Amounts of water and fiber also seem to matter.

 

[Siv]

Hamster,

Guess what ? I was looking at some of Gary Taube's online stuff and he has a response to the exact study you posted.

Here's the Q&A.

From http://www.healthcentral.com/diabetes/c/36758/20088/gary-round-3

Insulin Index
In some follow-up reading, I ran into the concept of the insulin index, which purports to index the insulin response of foods. This index appears to indicate that certain protein rich foods (like beef and fish) may actually have more impact on insulin that certain carbohydrate foods. This is counter-intuitive based on the science that Gary writes about. I would be interested to know whether Gary has any comments about this index.


It's always been known that protein stimulates an insulin response, because some of the amino acids in the protein are converted to glucose. The assumption has always been that this effect is small compared to that of carbohydrates, and that it is muted because it takes considerably longer to digest protein from meat, for instance, than it does glucose from high glycemic index carbohydrates. Moreover, protein also stimulates secretion from the pancreas of a hormone called glucagon, which is not the case with carbohydrates. Glucagon works opposite insulin on the fat tissue itself and so would be expected to mute or counteract entirely any fat accumulation stimulated by the insulin.

Another factor to keep in mind is that the paper cited most often as evidence for the insulin secretion in response to meat and fish -- a 1997 paper in the American Journal of Clinical Nutrition titled "An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods" -- used extremely lean steaks and whitefish for the measurement. The fish was roughly 90 percent calories protein and 10 percent fat and the meat was 70-30. The more interesting question, and the one more relevant to the arguments in the book, is what happens when the meat and fish are more in the neighborhood of 70 percent or even 80 percent fat by calories. That hasn't been addressed. In short, the assumption that our insulin is primarily regulated by the carbohydrates in the diet is a reasonable one and will tell us most of what we need to know when it comes to fat accumulation and chronic disease.

 

[Moonbear]

I'm entering this discussion late, and have not read every study posted. A few points and questions come to mind though.

First, I don't think you've demonstrated that there has been a "huge increase" in cancer in the population, which is required to make your initial claims that somehow carbohydrate consumption is responsible for this. With better diagnostics, there certainly is more cancer detected/diagnosed, but that doesn't mean it is more prevalent now than at other times in history.

Second, I don't think you've shown that a high carbohydrate diet is a big part of the problem. Can it contribute to some types of cancer? Yes. That seems to be the gist of the articles you've presented, but even in those, it seems the common denominator is actually development of type II diabetes. That first list of articles presented do not even all address cancer; several only address development of type II diabetes, which is not disputed by anyone reputable that I know of. The remainder discuss a specific type of breast cancer (the non-estrogen-receptor related type of breast cancer, which is not the most common type of breast cancer; the study in fact concluded there was no OVERALL increase in breast cancer, just of that one minor subtype), and pancreatic cancer. Since the pancreas is the secreter of insulin, it is perhaps not surprising that it would be the organ to malfunction in people who have consumed so much carbohydrates that they've become diabetic. Likewise, it could be that the cause and effect are reversed, and that those who have dysfunctions of their pancreatic cells predisposing them to cancer could also be more likely to develop diabetic complications.

Obesity severe enough to lead to type II diabetes is associated with a lot of other complications. If those people are overconsuming any nutrient to the point of developing diseases from it, that hardly means the nutrient is a bad nutrient if consumed in more reasonable quantities.

You seem able to locate peer-reviewed literature, so I'm wondering why you are continually referring to one particular book by one author rather than evaluating the literature as a whole for yourself? There are many types of cancer and trying to pin one single nutrient as the blame for all of it is not particularly reasonable, especially when even the literature you're providing is showing that there are prevalent forms of cancer that are NOT more frequent in people over consuming this nutrient.

Epidemiological studies are useful, but primarily for the development of hypotheses to test, not for forming strong conclusions. I think that's the issue here, that the opening post contained a fairly strong conclusion (blame carbohydrates) based on a premise that was not strongly supported in the first place (a huge increase in cancer). The evidence presented is far from conclusive. That's not to say there isn't something to the idea; maybe there is a connection between carbohydrate intake and certain types of cancer, and maybe that's particularly a concern for people predisposed to a particular type of diabetes, or maybe if they have already developed diabetes, there is a higher risk of certain types of cancer when particular diets are consumed.

In the longer term, developing appropriate nutritional advice for a population requires more than consideration of a single type of risk factor. For example, if you're trying to advise diabetics on how to adjust their diet, and certain foods put them at a higher risk of pancreatic cancer, but other foods put them at a higher risk of developing neuropathies, or a more rapid progression toward kidney failure and pulmonary edema, or atherosclerotic plaques leading to stroke, how would you weigh the risks and benefits of those different diets? That's the challenge with real patients and real diets.

So, I don't dismiss out of hand that a particular diet might have benefits for certain types of diseases, or in particular patient populations, or that there is more to study and learn about the mechanisms of those diets. However, when anyone promotes one single diet as a panacea for a broad class of diseases and across all members of the population, I become highly suspicious that they are just trying to sell books for a profit, and not really promoting scientific knowledge in a responsible way. I'm not sure if that's what's being done in the book you're discussing, because I have not read it. I'm basing that assumption on what you've presented of it here.

 

[Siv]

Hello Moonbear,

The reason I cite the book is because it is basically a compilation of tons of research, as I mentioned multiple times. GCBC is not a diet book, its a compilation of research by an award winning science journalist whose previous award winning works dealt with cold fusion and other physics subjects.

It is a very dry read and basically references tons of research to show how the current low-fat dogma has no research supporting it and how all the evidence points to carbohydrates (especially refined carbs and fructose) being responsible for most of the diseases of modern civilization.

He in fact does cite the serious limitations of epidemiological studies (I posted a link).

I respect his work, mostly becuase of the evidence based nature of it, but more importantly, becuase he is not a guy trying to sell a diet or make money off supllements. He is a science journalist who happened to look at the science being practised in the nutrition field, got appalled at the (lack of) quality there, and wrote a book.

 

[hamster143]

The reason I cite the book is because it is basically a compilation of tons of research, as I mentioned multiple times. GCBC is not a diet book, its a compilation of research by an award winning science journalist whose previous award winning works dealt with cold fusion and other physics subjects.

http://www.theatlantic.com/magazine/print/2010/11/lies-damned-lies-and-medical-science/8269/

80 percent of non-randomized studies (by far the most common type) turn out to be wrong, as do 25 percent of supposedly gold-standard randomized trials, and as much as 10 percent of the platinum-standard large randomized trials. ... researchers were frequently manipulating data analyses, chasing career-advancing findings rather than good science, and even using the peer-review process—in which journals ask researchers to help decide which studies to publish—to suppress opposing views.

...

49 of the most highly regarded research findings in medicine over the previous 13 years, as judged by the science community’s two standard measures: the papers had appeared in the journals most widely cited in research articles, and the 49 articles themselves were the most widely cited articles in these journals. These were articles that helped lead to the widespread popularity of treatments such as the use of hormone-replacement therapy for menopausal women, vitamin E to reduce the risk of heart disease, coronary stents to ward off heart attacks, and daily low-dose aspirin to control blood pressure and prevent heart attacks and strokes. Ioannidis was putting his contentions to the test not against run-of-the-mill research, or even merely well-accepted research, but against the absolute tip of the research pyramid. Of the 49 articles, 45 claimed to have uncovered effective interventions. Thirty-four of these claims had been retested, and 14 of these, or 41 percent, had been convincingly shown to be wrong or significantly exaggerated.

Don't trust anyone who has an agenda. Gary Taubes has an agenda. Dipping in the sea of contradictory medical research, he's virtually assured of finding enough articles to confirm his agenda to make him sound scientific.

 

[Moonbear]

It is a very dry read and basically references tons of research to show how the current low-fat dogma has no research supporting it and how all the evidence points to carbohydrates (especially refined carbs and fructose) being responsible for most of the diseases of modern civilization.

These are the sorts of over-generalizations I am taking issue with. Trying to point a finger at a single nutrient as responsible for most diseases is just as likely to end up proven wrong over time as pointing the finger at any other single nutrient.

I respect his work, mostly becuase of the evidence based nature of it, but more importantly, becuase he is not a guy trying to sell a diet or make money off supllements.

Okay, so he's just trying to make money selling a book.

He is a science journalist who happened to look at the science being practised in the nutrition field, got appalled at the (lack of) quality there, and wrote a book.

Science journalists are notoriously bad at understanding science. I cringe at how badly they tend to misrepresent scientific research. So, he's appalled at the lack of quality of research in a field, yet uses that research to support his opinions? Do you see the disconnection there? It sounds like he might simply not understand the scientific process. A lot of journalists don't, sadly. The journalists are often the ones guilty of over-hyping various fad diets and promoting unsound nutritional advice. Yes, there is a lot of popular dietary advice that is not well supported by the research, but that is primarily because of the journalists, not the scientists. Some of these newer diets are still being studied to find out if they are all they claim to be. You are correct that there are many diets around that have no scientific backing to them. It doesn't mean the science is bad, it means people have been doing a good job ignoring the science for a long time.

These articles might interest you. It gets at what nutritionists have known for years; it's not only the type of nutrient, but the source of it. Basically, not all sources of nutrients are created equal. So, a low carbohydrate diet can have different effects depending on what the source of the other nutrients in that diet include, such as animal fats/proteins, or vegetable fats/proteins.

http://www.ncbi.nlm.nih.gov/pubmed/20820038
http://www.ncbi.nlm.nih.gov/pubmed/17093250
http://www.ncbi.nlm.nih.gov/pubmed/18258623

Not too surprisingly, cutting back both carbohydrates AND animal fats/proteins seemed to have the best overall health outcomes in these studies.

Here are others comparing low fat vs low carbohydrate diets:
http://www.ncbi.nlm.nih.gov/pubmed/20807884
http://www.ncbi.nlm.nih.gov/pubmed/20713651
http://www.ncbi.nlm.nih.gov/pubmed/17556688

Of course, most of these studies are focusing on caloric restriction and weight loss, and none really compares a modest diet with more of a balance of nutrients and prevention of the weight gain in the first place. Obesity is a serious health problem in society today. However, the same nutrients that cause trouble when trying to lose weight may not be the ones that were to blame for the original gain of that weight. When an obese person is trying to lose weight, often they already have metabolic dysfunctions. That can change how they utilize nutrients compared to someone who hasn't developed those types of dysfunctions already.

 

[Siv]

http://www.theatlantic.com/magazine/print/2010/11/lies-damned-lies-and-medical-science/8269/

Don't trust anyone who has an agenda. Gary Taubes has an agenda. Dipping in the sea of contradictory medical research, he's virtually assured of finding enough articles to confirm his agenda to make him sound scientific.

Your article in fact supports my point that medical research has been abyssmal the past many decades. Something Taubes repeatedly reveals as well.

BTW what is his agenda ?!

On the contrary, many of the so-called studies claiming carbs are not so bad etc are often funded by the food industry

Here's another interesting article on the same - how pathetic the current medical establishment is ...
http://archinte.ama-assn.org/cgi/content/full/170/9/749
Less Is More - How Less Health Care Can Result in Better Health

 

[Siv]

These are the sorts of over-generalizations I am taking issue with. Trying to point a finger at a single nutrient as responsible for most diseases is just as likely to end up proven wrong over time as pointing the finger at any other single nutrient.

Thats a nice sounding statement.
However, its an over-generalization as well. It may be your opinion, sure.
However, it is quite possible that one nutrient is responsible for a whole host of modern diseases, simply because we never ate so much of it for most of our evolutionary history.

Science journalists are notoriously bad at understanding science. I cringe at how badly they tend to misrepresent scientific research.

Another over generalization and opinion.

So, he's appalled at the lack of quality of research in a field, yet uses that research to support his opinions? Do you see the disconnection there? It sounds like he might simply not understand the scientific process. A lot of journalists don't, sadly.

Wow, tons of opinion and prejudices there.
I don't see a disconnection there.
What he is saying is that the current low-fat dogma is not based on any evidence. And in fact shows what the real research indicates. And the low-fat mantra has made people gobble up carbs like there is no tomorrow, which has resulted in tons of problems.

I think instead of spewing generalizations and prejudices, you should read his book and refute the evidence there. A google search can throw up articles that support both low-carb and low-fat. Depending on what agenda the person has.

Plus remember, its hard for the establishment to admit that it has been wrong. How many times have we seen that before ? So that's nothing new.

These articles might interest you. It gets at what nutritionists have known for years; it's not only the type of nutrient, but the source of it. Basically, not all sources of nutrients are created equal. So, a low carbohydrate diet can have different effects depending on what the source of the other nutrients in that diet include, such as animal fats/proteins, or vegetable fats/proteins.

http://www.ncbi.nlm.nih.gov/pubmed/20820038
http://www.ncbi.nlm.nih.gov/pubmed/17093250
http://www.ncbi.nlm.nih.gov/pubmed/18258623

Not too surprisingly, cutting back both carbohydrates AND animal fats/proteins seemed to have the best overall health outcomes in these studies.

Here are others comparing low fat vs low carbohydrate diets:
http://www.ncbi.nlm.nih.gov/pubmed/20807884
http://www.ncbi.nlm.nih.gov/pubmed/20713651
http://www.ncbi.nlm.nih.gov/pubmed/17556688

Of course, most of these studies are focusing on caloric restriction and weight loss, and none really compares a modest diet with more of a balance of nutrients and prevention of the weight gain in the first place. Obesity is a serious health problem in society today. However, the same nutrients that cause trouble when trying to lose weight may not be the ones that were to blame for the original gain of that weight. When an obese person is trying to lose weight, often they already have metabolic dysfunctions. That can change how they utilize nutrients compared to someone who hasn't developed those types of dysfunctions already.

Your second study concludes this - "CONCLUSIONS: Our findings suggest that diets lower in carbohydrate and higher in protein and fat are not associated with increased risk of coronary heart disease in women. When vegetable sources of fat and protein are chosen, these diets may moderately reduce the risk of coronary heart disease. "

Your third study : "CONCLUSION: These data suggest that diets lower in carbohydrate and higher in fat and protein do not increase the risk of type 2 diabetes in women. In fact, diets rich in vegetable sources of fat and protein may modestly reduce the risk of diabetes."

Shall I now cite studies showing low carb, high fat/protien is good ?

http://www.annals.org/content/153/3/147.abstract?aimhp
"Conclusion: Successful weight loss can be achieved with either a low-fat or low-carbohydrate diet when coupled with behavioral treatment. A low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors at 2 years. "
http://jama.ama-assn.org/cgi/reprint/297/9/969
http://www.nejm.org/doi/pdf/10.1056/NEJMoa0708681

But seriously, do you know how complicated a subject nutrition actually is ?
It is nothing as simple as low-carb is good or low-fat is bad.

There are tons of subtleties. Industrial seed oils for eg. are the devil, because they are sky high in omega-6 fats which are terrible for us. So any high fat diet which makes rats gorge on tons of O6 really is not showing anything.
Similarly, there is lots of difference between pasture fed dairy and grain fed dairy.
Also, today's meat farms inject all sorts of hormones and antibiotics into the animals, which have been known to be very harmful.

Even in carbs, tubers, although they do make your blood sugar shoot up are far less harmful than refined flour, sugar or HFCS. All vegetables have some carbs but are definitely ok (except for the real high carb ones).

Its the trying to simplify objective that resulted in this mess in the first place. The simplistic notion that dietary fat gets simply converted into body fat. Or that calorie dense foods are to be avoided, period.

Please read the blogs of some modern experts who are not afraid to question established dogma in nutrition.

http://wholehealthsource.blogspot.com/
http://www.paleonu.com/
http://heartscanblog.blogspot.com/
http://high-fat-nutrition.blogspot.com/
http://www.cholesterol-and-health.com/cholesterol-blog.html

 

[Proton Soup]

Siv, do you think Michael Phelps is going to get diabetes?

https://www.youtube.com/watch?v=QXRvXtcSu14

 

[Proton Soup]

These articles might interest you. It gets at what nutritionists have known for years; it's not only the type of nutrient, but the source of it. Basically, not all sources of nutrients are created equal. So, a low carbohydrate diet can have different effects depending on what the source of the other nutrients in that diet include, such as animal fats/proteins, or vegetable fats/proteins.

http://www.ncbi.nlm.nih.gov/pubmed/20820038
http://www.ncbi.nlm.nih.gov/pubmed/17093250
http://www.ncbi.nlm.nih.gov/pubmed/18258623

Not too surprisingly, cutting back both carbohydrates AND animal fats/proteins seemed to have the best overall health outcomes in these studies.

Here are others comparing low fat vs low carbohydrate diets:
http://www.ncbi.nlm.nih.gov/pubmed/20807884
http://www.ncbi.nlm.nih.gov/pubmed/20713651
http://www.ncbi.nlm.nih.gov/pubmed/17556688

Of course, most of these studies are focusing on caloric restriction and weight loss, and none really compares a modest diet with more of a balance of nutrients and prevention of the weight gain in the first place. Obesity is a serious health problem in society today. However, the same nutrients that cause trouble when trying to lose weight may not be the ones that were to blame for the original gain of that weight. When an obese person is trying to lose weight, often they already have metabolic dysfunctions. That can change how they utilize nutrients compared to someone who hasn't developed those types of dysfunctions already.

speaking of these, i think a lot of what the DASH studies and some of these others are pointing to wrt to vegetable instead of grain sources of carbs is an increase in consumption of potassium and reduction of sodium. perhaps also magnesium.

 

[Siv]

Siv, do you think Michael Phelps is going to get diabetes?

Depends on what his genes and diet are, doesn't it

 

[Verimius]

Gary Taubes' bio indicates he thoroughly understands science: http://www.garytaubes.com/bio/. If you want to refute him, you'll have to do it based on the science he uses, not on the percentage of medical studies that may or may not be reliable.

His thesis is exactly that a single macronutrient, carbohydrates, is responsible for obesity, diabetes, and many other diseases that plague us. If you actually read his work, you'll find that he rigorously supports his thesis with a vast body of research going back over a century.

For those who found Good Calories, Bad Calories hard going, Taubes has a new book coming out at the end of December, "Why We Get Fat, and What to Do About It". This will be an easier, but still persuasive read.

 

[Siv]

Hey Verimius, thanks for joining this discussion - everyone was kind of ganging up on me

 

[Proton Soup]

i thought this recent story was interesting. will someone pass the ho-hos?

http://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor/index.html?section=cnn_latest"

For a class project, Haub limited himself to less than 1,800 calories a day. A man of Haub's pre-dieting size usually consumes about 2,600 calories daily. So he followed a basic principle of weight loss: He consumed significantly fewer calories than he burned.

His body mass index went from 28.8, considered overweight, to 24.9, which is normal. He now weighs 174 pounds.

But you might expect other indicators of health would have suffered. Not so.

Haub's "bad" cholesterol, or LDL, dropped 20 percent and his "good" cholesterol, or HDL, increased by 20 percent. He reduced the level of triglycerides, which are a form of fat, by 39 percent.

 

[Siv]

Haven't visited PF for a while since there wasn't much happening on this thread.

i thought this recent story was interesting. will someone pass the ho-hos?

http://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor/index.html?section=cnn_latest"

All low-carb bashers are grabbing on to this one study now

But there have already been lots of rebuttals on the web.

Here's my favourite one :
http://wholehealthsource.blogspot.com/2010/11/twinkie-diet-for-fat-loss.html

 

[douglerner]

His thesis is exactly that a single macronutrient, carbohydrates, is responsible for obesity, diabetes, and many other diseases that plague us. If you actually read his work, you'll find that he rigorously supports his thesis with a vast body of research going back over a century.

But is it "good science" to simply ignore the data which doesn't fit his thesis?

For example, the obesity rate in Japan is just 3%. Yet the typical diet is extremely high carbohydrate (multiple servings of white rice each day).

An overall theory has to explain this as well.

doug

 

[Albern]

Hello every one .,,
I totally agree with you.,... carb consumption and explosion of sugar are the reasons but Smoking Is also another reason of cancer that is increasing day by day..

 

[nismaratwork]

Hello every one .,,
I totally agree with you.,... carb consumption and explosion of sugar are the reasons but Smoking Is also another reason of cancer that is increasing day by day..

Smoking is associated with a fairly limited (althogh stil large) number of cancers. You don't see any other reason for increased diagoses... nothing environmental, or to do with an aging population?

 

[treehouse]

http://www.ajcn.org/cgi/content/abstract/87/5/1384
http://www.ajcn.org/cgi/content/abstract/84/5/1171
http://www.ajcn.org/cgi/content/full/80/2/348
http://www.ajcn.org/cgi/content/abstract/86/5/1495
http://www.ajcn.org/cgi/content/abstract/86/4/899
http://www.ajcn.org/cgi/content/abstract/91/3/535

More and more evidence suggests carbs are the culprit, not fat - not just for cancer but diabetes, CHD and CVD. Please read "Good Calories, Bad Calories" by Gary Taubes for a ton of evidence, journal articles and references. Also read Dr. Bernstein, the Whole Health Source Blog, Heart Scan Blog and Panu.

Does the last one suggest that sugar is carcinogenic?

 

[treehouse]

http://www.theatlantic.com/magazine/print/2010/11/lies-damned-lies-and-medical-science/8269/
Don't trust anyone who has an agenda. Gary Taubes has an agenda. Dipping in the sea of contradictory medical research, he's virtually assured of finding enough articles to confirm his agenda to make him sound scientific.

Benevolent agendas are. When a doctor recommends a course of treatment, that plan is an agenda toward the end of patient health. Ask this man: http://news.stanford.edu/news/2011/august/ehrlich-scientist-advocates-081111.html

you can deduce an object's trajectory within a tactically satisfactory margin of error without computing the vectors that determine exactly where it winds up in that margin. Science can inform us of a correct course of action.

 

[tkav1980]

the increase in obesity isn't about carbs, it's about eating too many calories. Taubes is a fruitcake.

I have a fantastic example of this. If you look around online you can find a diet outline called skiploading. You're literally eating doughnuts, fruitty pebbles, pasta, candy etc on the weekends and ending up sub 6% bodyfat. Total calorie expendature in any given time frame is greater than total caloric intake with the exception of re-feed days. However, from my understanding of it, these high carb re-feeds are used to restore glycogen levels that have been severely depleted through extremely low carbs, less that 50 Grams per day, while doing extremely strenuous weight training.


I used this diet for contest prep 2 years ago and it worked wonders as long as the re-feed is timed so that you start it a few hours before the contest, right after you drop your water.

 

[treehouse]

I have a fantastic example of this. If you look around online you can find a diet outline called skiploading. You're literally eating doughnuts, fruitty pebbles, pasta, candy etc on the weekends and ending up sub 6% bodyfat. Total calorie expendature in any given time frame is greater than total caloric intake with the exception of re-feed days. However, from my understanding of it, these high carb re-feeds are used to restore glycogen levels that have been severely depleted through extremely low carbs, less that 50 Grams per day, while doing extremely strenuous weight training.


I used this diet for contest prep 2 years ago and it worked wonders as long as the re-feed is timed so that you start it a few hours before the contest, right after you drop your water.

Timothy Ferriss would say that the weekly binging keeps the body from slowing its metabolism to adjust to the diet.