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Fred - you've cited Volek a few times now. Well, the co-author of his recent work (Cassandra), who's worked closely with Volek for the past 5 years just told you that you're mostly wrong. Is it fair enough to say that you might wanna reconsider things? Plus, look at Cassandra's guns.
Reconsider what? She admits that the majority of the people she has studied fared better on a low carb keto diet. Some didn't. Yet, her research is not conducted in a ward so it is quite possible that since the majority of people fared better on a LCKD than a low fat, some of the subjects in the LCKD cheated?
And I don't see you or anyone else here demanding that she lay down her references and citations. When people post here who agree with each other it's all taken at face value. But when I post, uh, uh.
RE the Dasinger study you cited as evidence to refute the A to Z study, I believe this is the macronutrient breakdown for the entire 12 months:
If you can see it, the ALL 4 groups at roughly the same level of carbohydrate over the whole year. The carbohydrate intake was significantly higher than what an Atkins diet recommends and is far higher than the Atkins group in the A to Z study.
The protein intake on average was higher in the Zone than in Atkins and even the WW protein intake was close to the Atkins.
The Atkins group also had the lowest adherence rate.
Just this alone indicates that this study is a poor one to choose to refute the A to Z diet.
I'll get to the others tomorrow. I can already see some errors in the Brinkworth paper. It's isocaloric, so they lock the calories low for both groups -- 1400 to 1500 calories. And then they say both groups lost similar amounts of weight but the low carb group lost 3 kilograms more.
The 2 threads were becoming unwieldy. Comments within comments that were often doubled and tripled up. That's all.
If that's your reason for closing the thread, then why didn't you just break up the posts into smaller sections instead? Like starting a thread about the Swinburn paper, and starting a different thread about Alan's papers, for example. That would make a helluva lot more sense (and not make you appear like you're running from the discussion) than posting a super long response and then closing the thread right afterwards.
Yet, her research is not conducted in a ward so it is quite possible that since the majority of people fared better on a LCKD than a low fat, some of the subjects in the LCKD cheated?
The same claim could be made of the A to Z study...that people on the non-keto diets cheated.
That's why not a single study that uses self report of energy intake is adequate for testing the MA hypothesis.
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If you can see it, the ALL 4 groups at roughly the same level of carbohydrate over the whole year. The carbohydrate intake was significantly higher than what an Atkins diet recommends and is far higher than the Atkins group in the A to Z study.
This is a very valid criticism of the Dasinger paper, which, again, why no studies that use self report (whether it's Dasinger or A to Z) are appropriate for addressing the MA hypothesis.
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I can already see some errors in the Brinkworth paper. It's isocaloric, so they lock the calories low for both groups -- 1400 to 1500 calories.
That's not an error in the paper. That's a strength. They SHOULD be isocaloric if you're trying to test the MA hypothesis (although you're still going to have the problems with self report with the Brinkworth paper as you will with all of these papers).
However, Brinkworth's method of self-report (weighed 3-day food records every 2 weeks for an entire year) was superior to the A to Z method (24-hour recall at only 4 time points through an entire year).
Now, you can't argue that both groups were "low carb" just because they were low calorie, because the low-fat group consumed 150-200 grams of carbohydrate per day....well above ketogenic levels. This was confirmed by ketone testing....the low carb group had significantly elevated ketone levels, while the low fat group did not.
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And then they say both groups lost similar amounts of weight but the low carb group lost 3 kilograms more.
These differences were not statistically significant, so by definition the amount of weight lost was similar.
Now, one could argue that a Type II statistical error is possible here, which is a valid point, especially given that the confidence interval for the difference was quite skewed in the favor of the low carb group. However, when one looks at the body composition data, the low carb group lost significantly more fat-free mass than the other group. This would be consistent with the greater water loss typically observed in low-carb groups. This is also consistent with my meta-analysis which showed greater FFM loss on ketogenic diets.
Overall, none of the 4 papers cited by Alan or the A to Z paper cited by Fred can be considered adequate evidence for or against the MA hypothesis, due to the problems with self report.
The only halfway decent paper on humans is the Johnston paper from AJCN 2006, which doesn't favor the MA, but that one is limited by the short trial duration, the low subject numbers, and the lack of measurement of 24-h energy expenditure.
My meta-analysis published in AJCN in 2006 favors the MA hypothesis, but since it included trials with self-report, it can only be considered as limited support for the hypothesis.
That leaves us with animal studies, and there are 2 studies favoring the MA hypothesis and 2 studies that don't, so again the data is equivocal.
The problem with the ward studies (cited by Buchholz & Schoeller) talked about here is that none of them were ketogenic and the subjects were in energy balance. The ward studies only show that, at NON-ketogenic carb levels, varying the fat/carbohydrate ratio makes no difference in energy expenditure or weight.
So, this is what the evidence says:
1. The proposed MA for low carb diets is a hypothesis, not a fact
2. There is inadequate data to support the MA hypothesis
3. There is inadequate data to reject the MA hypothesis
4. The MA hypothesis does not trump the concept of energy balance. It postulates inefficiencies in energy metabolism, which would translate to an increase in measured energy expenditure (due to heat loss) in a living organism. Thus, if the MA was true, "calories out" would increase for a given "calories in".
5. A definitive study examining 24-hour energy expenditure (using room calorimetry), comparing a ketogenic diet to a traditional diet (with matched protein intake) for subjects in an energy deficit, has not been performed. This is the only study that will adequately test the MA hypothesis in humans
6. Weight loss still requires an energy deficit. If a MA exists, it still cannot make up for an energy surplus or energy balance. To assert otherwise is to assert that energy can be created or destroyed out of thin air, or that human tissue can be created in the absence of any energy input.
That's it in a nutshell. Thus, I would contend that both sides here have made some mistakes regarding their assertions and positions.
The problem with the ward studies (cited by Buchholz & Schoeller) talked about here is that none of them were ketogenic and the subjects were in energy balance. .
Why would the subjects being in energy balance be a problem? or does the MA only 'exist' during caloric restriction?
oh, and metabolic ward studies with keto diets did your list include
Composition of weight lost during short-term weight reduction. Metabolic responses of obese subjects to starvation and low-calorie ketogenic and nonketogenic diets.
Yang MU, Van Itallie TB.
The effects of starvation, an 800-kcal mixed diet and an 800-kcal ketogenic (low carbohydrate-high fat) diet on the composition of weight lost were determined in each of six obese subjects during three 10-day periods.The energy-nitrogen balance method was used to quantify the three measurable components of weight loss; protein, fat, and water. On the 800-kcal ketogenic diet, subjects lost (mean +/- SE) 466.6 +/-51.3 g/day; on the isocaloric mixed diet, which provided carbohydrate and fat in conventional proportions, they lost 277.9+/- 32.1 g/day. Composition of weight lost (percentage) during the ketogenic diet was water 61.2, fat 35.0, protein 3.8. During the mixed diet, composition of loss was water 37.1, fat 59.5, protein 3.4...
Fred, why do you continue to dodge PowermanDL's question? And don't respond that he's being "childish" because that's not answering the question.
But isn't he behaving rudely, snidely and in a confrontational manner?
I want to hear you state right here in front of all members that you personally think that Powerman is being civil, polite and seriously interested in a decent and calm debate/discussion on the issues.
If you can honestly state such, I'll answer the question - whatever it is.
But isn't he behaving rudely, snidely and in a confrontational manner?
A red herring. Your perception of Powerman DL's tone is irrelevant to the question at hand.
If you do not like his tone, then I will ask you the same question. Would you please explain how you propose that insulin will create mass out of nothing?
The same claim could be made of the A to Z study...that people on the non-keto diets cheated.
That's why not a single study that uses self report of energy intake is adequate for testing the MA hypothesis.
****Fine. But why then wasn't Cassandra called out on this? Why was her post so warmly welcomed as proof that I was wrong? Perhaps her data is just as skewed as the A to Z? If we are going to argue that ONLY ward diet studies are valid, then you, Alan and the rest of us must not use anything BUT ward studies to counter or support our positions WRT weight loss and weight gain - agreed? If we are going to include non ward studies in our debate then you can't point fingers and say, for example, that the A to Z is invalid because it is non ward. You can say it is weaker than other non ward studies due to self report, due to length, etc. But let's keep the non ward part out of the picture.
This is a very valid criticism of the Dasinger paper, which, again, why no studies that use self report (whether it's Dasinger or A to Z) are appropriate for addressing the MA hypothesis.
****Why then did Alan use this paper as 'proof' that there is research out there that indicates the opposite of the A to Z? This paper isn't even reasonably close. Did you, Mike and Alan miss this table somehow? It took me all of 5 seconds to see that this paper is useless if used to 'disprove' the A to Z paper. And I am accused of not reading the research? Do you mean to suggest that the subjects in the Dashinger study over reported their carb intake? Are you saying this paper is worthless? Again, if so, why did Alan use it?
That's not an error in the paper. That's a strength. They SHOULD be isocaloric if you're trying to test the MA hypothesis (although you're still going to have the problems with self report with the Brinkworth paper as you will with all of these papers).
****You are referring to the Brinkworth paper here. I disagree. The key is to do the studies high calorie, not low calorie. That's when the metabolic advantage will make itself known.
A low calorie diet is by default low in carbs compared to baseline. Look at the Dasinger paper table. Save for the Ornish diet group ALL of the other 3 significantly lowered their carb intake. So what I am saying is that if the LFHC group went from eating 300gms of carbs a day to 174gsm (averaged over the year) and the LCHF group went from 300gms to 30 grams, the TOTAL decrease can be the reason why the LFHC group did so well.
Realize that the LCHF group did lose 6 pounds more than the HCLF group in the end. Total energy intake was also higher across the 12 months in the LCHF group as well. In fact, look at the calorie intakes of both groups. Over the course of the year, the LC group consumed 588,000 calories - LF group consumed 567,308 calories (based on reported calorie intakes at each interval. I calculated out for each group for the year to find the total intakes, meaning, the low-fat group over the year consumed 20,692 fewer calories than the low-carb group.
According to the calorie theory, the low-fat group should have lost 5.9 more pounds than the low-carb group based on calorie intake, especially since the groups were well matched for BMI and baseline body weight.
At the end of the year though, the low-carb group lost 32 pounds compared to the low-fat groups loss of 25.5 pounds. While not statistically significant, the researchers don't offer any explanation as to why the low-carb group consumed more calories over the year and still lost more weight than the low-fat group. MA anyone? Don't you think they should have? Why didn't they?
I'm almost sure that even though James you stated that the Brinkworth paper's method of self report was superior to the A to Z, to nay say my critique you'll retort by saying that the Brinkworth method still was totally unreliable to which I will respond by saying "So why did Alan cite it?"
Also worth noting is that the protein content of the LCHF group was MUCH higher YET the differences in fat loss was slight. It has been said here by a few folks that higher protein intakes are responsible for superior fat loss rather than low carb. Given the VAST difference in this study in protein intake, this paper doesn't seem to support that argument. So from now on when you all criticize papers I present to indicate the superiority of a LC diet, please don't use the higher protein intake as the deciding factor OR don't use papers like this one as ammunition that LC diets fare no better than HC diets.
Given all I've said thus far 2 of the 4 papers Alan cited are not particularly good ammo to shoot down the MA. Quite the contrary.
However, Brinkworth's method of self-report (weighed 3-day food records every 2 weeks for an entire year) was superior to the A to Z method (24-hour recall at only 4 time points through an entire year).
****Discussed above and agreed - the Brinkworth method of self report was a better method. However, in this study the Atkins diet group was not an Atkins diet group in the least. In the A to Z it was far closer. And as carbs reportedly rose in the A to Z, so did weight gain. All of the other groups in the A to Z had carbs at about the same level of carbs and experienced about the same results.
Now, you can't argue that both groups were "low carb" just because they were low calorie, because the low-fat group consumed 150-200 grams of carbohydrate per day....well above ketogenic levels. This was confirmed by ketone testing....the low carb group had significantly elevated ketone levels, while the low fat group did not.
****Nope, sorry. I touched on this above but to expand. You don't have to have ketones in the urine to lose fat. I never said you have to go on a keto diet to lose fat. I said low carb. And though the Brinkworth study doesn't mention baseline carbs per day, given the many studies that do include BL carb gms. p/d, it appears that they entered the study eating close to double the amount of carbs per day than ingested in the study. Yes, I speculate here, but I think my speculation is valid.
These differences were not statistically significant, so by definition the amount of weight lost was similar.
****May I remind you of the calorie disparity.
Now, one could argue that a Type II statistical error is possible here, which is a valid point, especially given that the confidence interval for the difference was quite skewed in the favor of the low carb group. However, when one looks at the body composition data, the low carb group lost significantly more fat-free mass than the other group. This would be consistent with the greater water loss typically observed in low-carb groups. This is also consistent with my meta-analysis which showed greater FFM loss on ketogenic diets.
****One statistical point James - I'm not a statistician, but they use standard error of the mean (SEM) which always makes the data look better than it is. More appropriate is the standard deviation. To convert to SD, I multiplied their SEM by square root of n, which I think is about 50. So that is about 7 which shows a much wider spread in the individual data.
And a mere 2 pounds less water over an entire YEAR due to the VLCD is nothing. Please refer back to the calorie issue.
Also, their bias is glaring. "Whilst a high carbohydrate, low fat (low saturated fat), moderate energy restricted diet (HC) remains the ‘best-practice’ for weight management…” Even with the quotation marks, the sentence is wrong. LF is the most commonly recommended energy restricted diet, but the Women’s Health Initiative is one study that shows it is not ready to be considered ‘best-practice’.
And there's more on this issue and but this gets off track.
The Stern study, posted by Alan to indicate that the A to Z diet (LC vs. LFHC and/or CR) was inferior, concluded that the LC group fared better than the LFCR diet.
In this study like the Brinkworth study, the LC group ate more total calories than the LF group over the course of the 6 month study yet lost significantly more weight -5.8kg vs. -1.9kg.
(And I must add that the conclusions of this study reek of lowcarbophobia.)
Let's look at the last one - the Foster study.
In the Foster study the same results were found - the LC group lost significantly more weight than the conventional diet group. However, at the 12 month mark they were roughly the same. Let's investigate why.
This study for whatever reason did not include a table for the macronutrient breakdown. But it did incldue a weight loss table and a urinary ketone table.
As we all know, urinary ketones are a sign that a person is on a VLCD. It can be used as proof that a person is indeed sticking to a low level of carb intake.
If you look at these two tables you can clearly see that at the 6 month mark - tha point where the researchers claim that both groups started to even out in weight loss, urinary ketones dropped precipitously. In the study the researchers state:
"For the first two weeks, carbohydrate intake is limited to 20 g per day and is then gradually increased until a stable and desired weight is achieved."
Say what? Notice that as time went on, if indeed the subjects heeded the advice of the researhers, they would have increased carbohydate consumption little by little which should result in lower ketones in the urine - and it did. As carbs rose, ketones lowered and weight loss slowed. This happened in the A to Z diet as well. Coincidence? I think not.
Clearly we need to see the table to determine how much carbohydrate increased by but increase it did according to the urinary ketone chart.
Moreover, the CD was limited in calories to an average of 1500 for both men and women yet the LC group was ad libitum. We cannot know for sure, but my guess is that the LC group ate more total calories than the CD group as happened in the Brinkworth and Stern studies yet still lost more total weight. Also note that the CD group DID in fact show signs of ketones in their urine indicating that they too were eating a low enough carbohydrate diet compared to their baseline. IOW, the very low cal nature of the diet put them in a very mild state of ketosis. So this was more of a very keto diet vs a very mild keto diet. My guess is that if the CD group was also ad libitum, the LC group would have lost even more weight comparatively.
Not to mention that in ALL 4 studies Alan cited, internal health markers were improved to the same or greater degree in the LC groups. But that is not the focus of this discussion.
Thus far I think I have shown you that the 4 studies Alan cited do not in anyway show "the exact opposite" results of the A to Z. In fact, not one of them even counters it.
Got 4 more?
Now, once again, if you want to cry afoul by stating that the A to Z study was not a ward study and that only ward studies can tell us that a MA is bogus or true, where are they? If there are none, then we are left only with what we have and what we have thus fat favors LC for fat loss over anything else for the reasons I have already explained, here and on my blogs.
CAUTION: I will only respond to civil, well thought out, respectful and congenial comments. If I have erred, fine. Point it out clearly and refrain from insinuations. I only came back because I saw Cassandra's comment and since she and Jeff work together and I highly respect Jeff, I figured I'd address her comment. Whoever moderates this board I suggest you calm down your natives and promote civil discussions.
A red herring. Your perception of Powerman DL's tone is irrelevant to the question at hand.
If you do not like his tone, then I will ask you the same question. Would you please explain how you propose that insulin will create mass out of nothing?
Nice duck.
I don't understand your question. Please rephrase.
Why would the subjects being in energy balance be a problem? or does the MA only 'exist' during caloric restriction?
Fine & Feinman's argument is that a ketogenic state would increase the demands on protein and amino acid turnover for gluconeogenesis. Because this process has a high energy cost, it would increase the energy deficit for a given energy intake.
If this hypothesis is true, this does not mean the MA would not exist in an energy balance state. But it does imply that it would be more apparent in an energy deficit (given that demand for gluconeogenesis would be higher in an an energy deficit). This is why my proposed study design would be on subjects in an energy deficit...to amplify any effect and make it easier to detect (if an effect exists at all).
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oh, and metabolic ward studies with keto diets did your list include
Composition of weight lost during short-term weight reduction. Metabolic responses of obese subjects to starvation and low-calorie ketogenic and nonketogenic diets.
There are 4 limitations to the Yang paper. First, the time period was too protracted (only 10 days) to detect any meaningful differences in body composition.
Second, they did estimate total daily energy expenditure, but they did it by estimating the cost of physical activity (recorded by the subjects in a diary), and then adding that cost onto BMR. This is not a reliable way to measure 24-hour energy expenditure, at least if you are trying to determine the existence of a MA (as it would be too insensitive and subject to error).
Third, the study only had 6 subjects, giving inadequate statistical power to detect any meaningful differences among conditions.
Fourth, the researchers estimated fat loss from the changes in energy balance (which itself was estimated). Thus, you have error compounding upon error. This also presents a problem when trying to test the MA hypothesis. If you are estimating fat loss from the changes in energy balance, and your measurements of energy balance are only a rough estimation, then your experiment is automatically biased against the MA hypothesis in terms of fat changes, as any undetected differences in energy balance will automatically result in no difference in fat loss.
Now, keep in mind I am not contending that the MA exists. I am only contending that there are limitations to both the data that supports it, and the data that rejects it.
Fred, I do not address red herrings in discussions.
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I don't understand your question. Please rephrase.
It is simple. You have consistently blamed insulin (not energy imbalance) as responsible for fat gain. This implies that insulin can create fat mass out of nothing. You have been asked to explain how insulin can create fat mass without the energy needed to create that mass.
The Stern study, posted by Alan to indicate that the A to Z diet (LC vs. LFHC and/or CR) was inferior, concluded that the LC group fared better than the LFCR diet.
Our discussion is about effects on bodyweight/body composition. Gotta stay on topic. No significant weight loss differences were seen between groups. That's my point. Also, regarding some key issues, let me quote Stern et al directly:
"Although it has been speculated that a low-carbohydrate diet would facilitate weight loss by promoting the metabolism of adipose tissue (13), our data suggest that weight loss differences may be explained by lower caloric intake on a low-carbohydrate diet. If true, this may be attributable to the simplicity of a low-carbohydrate diet or to greater effects on satiety. Of note, persons on the low-carbohydrate diet who dropped out of the study were less likely to lose weight, whereas those assigned to the conventional diet lost a similar amount of weight whether or not they remained in the study. This observation, together with the difference between diets in weight loss beyond 6 months, raises the possibility that a low-carbohydrate diet is less sustainable than a conventional diet."
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In this study like the Brinkworth study, the LC group ate more total calories than the LF group over the course of the 6 month study yet lost significantly more weight -5.8kg vs. -1.9kg.
Nope, wrong. The weight loss differences were not significant. To boot, the low-carb group lost more fat-free mass. Let me quote Brinkworth et al:
"Overall, volunteers lost weight during the first 24 wk of the study and continued to lose weight throughout the final 28 wk, albeit at a slower rate (Figure 3). By mixed-model analysis, using data from all participants who began the study, including those who discontinued the study, there was a significant reduction in weight (P < 0.001), but no significant difference between diets"
"FFM decreased to a greater extent in the LC group than in the LF group (P = 0.03 for time x diet interaction; Table 3); however, this difference was no longer significant after differences in FM loss were controlled for (P = 0.06), which suggests that the greater reduction in FFM in the LC diet group was a direct effect of the greater absolute weight loss observed in those subjects."
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Let's look at the last one - the Foster study.
In the Foster study the same results were found - the LC group lost significantly more weight than the conventional diet group. However, at the 12 month mark they were roughly the same. Let's investigate why.
Speculate all you want, Fred. But it doesn't change the fact that no significant difference was seen in weight loss. So much for the weight loss 'magic' of switching out carbs for fat.
****One statistical point James - I'm not a statistician, but they use standard error of the mean (SEM) which always makes the data look better than it is. More appropriate is the standard deviation. To convert to SD, I multiplied their SEM by square root of n, which I think is about 50. So that is about 7 which shows a much wider spread in the individual data.
This is irrelevant and is only a matter of data presentation. It has no bearing on whether significant differences are observed or not.
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Also, their bias is glaring. "Whilst a high carbohydrate, low fat (low saturated fat), moderate energy restricted diet (HC) remains the ‘best-practice’ for weight management…” Even with the quotation marks, the sentence is wrong. LF is the most commonly recommended energy restricted diet, but the Women’s Health Initiative is one study that shows it is not ready to be considered ‘best-practice’.
This is another red herring. It is irrelevant to the study results and whether or not it supports the MA hypothesis.
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In this study like the Brinkworth study, the LC group ate more total calories than the LF group over the course of the 6 month study yet lost significantly more weight -5.8kg vs. -1.9kg.
This is false, Fred. There was no significant difference in energy intake at 6 months. At 12 months, the low carb diet group ate less, but this also was not significant (although the confidence interval was heavily skewed in favor of lower energy intake for the low carb group).
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Thus far I think I have shown you that the 4 studies Alan cited do not in anyway show "the exact opposite" results of the A to Z. In fact, not one of them even counters it.
Fred, this is partly false. You are correct that there are limitations of the designs for the Foster and Dasinger papers are inadequate compared to the A to Z trial. However, you are incorrect in your assessments of the Stern and Brinkworth trials. The Brinkworth trial used a superior method of assessing energy intake, and did not observed a significant difference among the groups. There was a trend for lower energy intake in the low carb group in the Stern trial at 1 year, but again there was not a significant difference in weight change among groups.
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a MA is bogus or true, where are they? If there are none, then we are left only with what we have and what we have thus fat favors LC for fat loss over anything else for the reasons I have already explained, here and on my blogs.
It's already been explained that the reasoning that you have provided suffers from severe flaws.
Fred, I do not address red herrings in discussions.
It is simple. You have consistently blamed insulin (not energy imbalance) as responsible for fat gain. This implies that insulin can create fat mass out of nothing. You have been asked to explain how insulin can create fat mass without the energy needed to create that mass.
Strawman. That is not at all what I said and you know it.
Obesity is a disorder of excess fat accumulation. The question is why have so many more people becoming obese in the last few decades? Our genetics have not changed in the past 30 years. What's the cause? Are we just eating more food? Are we less active? Are we more stressed out? These are superficial and shallow axioms - more information is required. The NHANES Data reveals something interesting.
Carbohydrate has increased significantly.
Insulin is increased when dietary carbohydrate is increased, and one of the primary roles of insulin is fat storage. I've already discussed this at length as best as I could. The more carbs you eat, the more fat you will store - potentially. Fat does not increase insulin secretion and though protein does, the mechanisms are different.
I did not say insulin makes fat from nowhere. I said that in the presence if an elevated level of insulin due to carbohydrate ingestion fat storage is promoted and enhanced.
And no - if you eat a cup of table sugar and that is all the calories you eat for the day, you won't get fatter - probably. But that is not the point at all.
****You are referring to the Brinkworth paper here. I disagree. The key is to do the studies high calorie, not low calorie. That's when the metabolic advantage will make itself known.
Then please explain how the MA does not exist in low calorie conditions, but then magically appears in higher calorie conditions.
Second, you are contradicting yourself. You claim the energy intake in this trial is somehow too low, yet it is only approximately 200 calories/d lower than the A to Z trial (don't go by what the researchers prescribed....go by what the subjects reported). You can't use the A to Z trial to support your position, but then claim that the Brinkworth trial isn't valid because the energy intake is too low. There is not a meaningful difference in energy intake between the trials.
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A low calorie diet is by default low in carbs compared to baseline. Look at the Dasinger paper table. Save for the Ornish diet group ALL of the other 3 significantly lowered their carb intake. So what I am saying is that if the LFHC group went from eating 300gms of carbs a day to 174gsm (averaged over the year) and the LCHF group went from 300gms to 30 grams, the TOTAL decrease can be the reason why the LFHC group did so well.
But the proposed MA to low-carb diets is for KETOGENIC diets; it is already clear that no such MA exists for non-ketogenic diets. Your argument that a low calorie diet is by default low carbohydrate has no bearing on the MA hypothesis; the carbohydrate intake is simply not low enough to have any significant biological effect.
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Realize that the LCHF group did lose 6 pounds more than the HCLF group in the end.
Again, not significantly different and thus cannot be certain that this is not a chance finding.
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Total energy intake was also higher across the 12 months in the LCHF group as well.
Again, not statistically different. In fact, the difference was never more than 80 calories (and was quite a bit less at most measured time points).
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In fact, look at the calorie intakes of both groups. Over the course of the year, the LC group consumed 588,000 calories - LF group consumed 567,308 calories (based on reported calorie intakes at each interval. I calculated out for each group for the year to find the total intakes, meaning, the low-fat group over the year consumed 20,692 fewer calories than the low-carb group.
Fred, you cannot use such math for 2 groups upon which the differences are not significant. You are simply compounding the error of the variances.
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At the end of the year though, the low-carb group lost 32 pounds compared to the low-fat groups loss of 25.5 pounds. While not statistically significant, the researchers don't offer any explanation as to why the low-carb group consumed more calories over the year
But they didn't consume more calories. You can't simply just look at the means and then claim they consumed more calories. Unless the differences are statistically significant, or at least the confidence interval suggests a strong trend, then you cannot make such a claim.
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****Discussed above and agreed - the Brinkworth method of self report was a better method. However, in this study the Atkins diet group was not an Atkins diet group in the least.
This is completely false. The carbohydrate intake in the Brinkworth paper was quite a bit lower than the A to Z trial. In fact, the carb intake in the Brinkworth paper was never more than 40 grams. You can't claim this is not an "Atkins diet group". The carb intake in the A to Z trial in the Atkins group, however, was at 140 grams at 12 months.
Thus, the low-carb group in the Brinkworth trial had a lower carb intake than the A to Z trial, yet Brinkworth did not observe significant differences. The fact is, Brinkworth is by far a superior trial, with different results from the A to Z.
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****Nope, sorry. I touched on this above but to expand. You don't have to have ketones in the urine to lose fat. I never said you have to go on a keto diet to lose fat. I said low carb.
Then at what point does a diet become low carb Fred? What is the cutoff point, and what would be the biological mechanism behind why this point would suddenly result in greater fat loss?
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****May I remind you of the calorie disparity.
May I remind you the calories aren't significantly different either, and you can't use the math you did because it does nothing other than compound the variance error.
Survey data can't show cause-and-effect, obviously. But if you're gonna cite it, go with something more recent. According to the USDA Economic Research Service, from 1970-2007, percentage of daily calories from added sugars decreased 1% during this period, whereas flours/cereals increased by 3%. Dairy is down 3%, with no change in percentage of fruit consumption. Meat, eggs, & nuts (collectively) are down by 4%. Vegetables are down by 1%. Added fats increased by 7%. And the clincher: total daily calorie consumption increased by 27.7%. Given this, it appears that the rise in obesity is due in large part to a net increase in calorie intake, rather than an increase in carbohydrate in particular.
Obesity is a disorder of excess fat accumulation. The question is why have so many more people becoming obese in the last few decades? Our genetics have not changed in the past 30 years. What's the cause? Are we just eating more food? Are we less active? Are we more stressed out? These are superficial and shallow axioms - more information is required. The NHANES Data reveals something interesting.
Carbohydrate has increased significantly.
Again, Fred, you are completely inconsistent in your standards of evidence.
Over on your board and your blog, you criticize the data on physical activity and weight maintenance for being all observational (even though it's not).
But you are happy to quote observational data if it supports your position.
You can't criticize studies for being observational and unable to establish cause/effect, and then turn around and use observational data to support your position!
On top of that, you are being selective in what you're looking at with the NHANES data (hence, confirmation bias). Energy intake also increased significantly. Why do you ignore that part?
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and one of the primary roles of insulin is fat storage.
I already showed you over on your board that this is not the primary role of insulin. Insulin certainly has powerful effects on fat metabolism, but these are mostly due to its effects on glucose.
And why do you ignore ASP, catecholamines, and the myriad of other factors that effect fat metabolism?
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I did not say insulin makes fat from nowhere. I said that in the presence if an elevated level of insulin due to carbohydrate ingestion fat storage is promoted and enhanced.
As I told you before on the other board, insulin does not operate by itself in a vacuum. Your viewpoint of insulin is overly simplistic and ignores the complex interactions of many hormones and other factors that affect fat metabolism.
You don't have to have ketones in the urine to lose fat. I never said you have to go on a keto diet to lose fat. I said low carb
Another note on this, Fred. My AJCN publication only showed a MA for ketogenic diets. No MA was observed for non-ketogenic carbohydrate levels. Thus, my own publication does not support your contention that it does not need to be ketogenic for a MA to exist.
I did not say insulin makes fat from nowhere. I said that in the presence if an elevated level of insulin due to carbohydrate ingestion fat storage is promoted and enhanced.
Then please explain how the MA does not exist in low calorie conditions, but then magically appears in higher calorie conditions.
Second, you are contradicting yourself. You claim the energy intake in this trial is somehow too low, yet it is only approximately 200 calories/d lower than the A to Z trial (don't go by what the researchers prescribed....go by what the subjects reported). You can't use the A to Z trial to support your position, but then claim that the Brinkworth trial isn't valid because the energy intake is too low. There is not a meaningful difference in energy intake between the trials.
But the proposed MA to low-carb diets is for KETOGENIC diets; it is already clear that no such MA exists for non-ketogenic diets. Your argument that a low calorie diet is by default low carbohydrate has no bearing on the MA hypothesis; the carbohydrate intake is simply not low enough to have any significant biological effect.
Again, not significantly different and thus cannot be certain that this is not a chance finding.
Again, not statistically different. In fact, the difference was never more than 80 calories (and was quite a bit less at most measured time points).
Fred, you cannot use such math for 2 groups upon which the differences are not significant. You are simply compounding the error of the variances.
But they didn't consume more calories. You can't simply just look at the means and then claim they consumed more calories. Unless the differences are statistically significant, or at least the confidence interval suggests a strong trend, then you cannot make such a claim.
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This is completely false. The carbohydrate intake in the Brinkworth paper was quite a bit lower than the A to Z trial. In fact, the carb intake in the Brinkworth paper was never more than 40 grams. You can't claim this is not an "Atkins diet group". The carb intake in the A to Z trial in the Atkins group, however, was at 140 grams at 12 months.
Thus, the low-carb group in the Brinkworth trial had a lower carb intake than the A to Z trial, yet Brinkworth did not observe significant differences. The fact is, Brinkworth is by far a superior trial, with different results from the A to Z.
Then at what point does a diet become low carb Fred? What is the cutoff point, and what would be the biological mechanism behind why this point would suddenly result in greater fat loss?
May I remind you the calories aren't significantly different either, and you can't use the math you did because it does nothing other than compound the variance error.
I don't have time to go tit for tat now on your comments to my comments which will result in more tit for tat ad infinitum.
Your comments do not change the fact that all 4 studies Alan cited either showed an advantage to LC diets for fat loss or were not LC diets (Dashinger) at all.
Let's move on.
Actually I meant the Dashinger study was not an Atkins diet - I mis-wrote.
Survey data can't show cause-and-effect, obviously. But if you're gonna cite it, go with something more recent. According to the USDA Economic Research Service, from 1970-2007, percentage of daily calories from added sugars decreased 1% during this period, whereas flours/cereals increased by 3%. Dairy is down 3%, with no change in percentage of fruit consumption. Meat, eggs, & nuts (collectively) are down by 4%. Vegetables are down by 1%. Added fats increased by 7%. And the clincher: total daily calorie consumption increased by 27.7%. Given this, it appears that the rise in obesity is due in large part to a net increase in calorie intake, rather than an increase in carbohydrate in particular.
Your comments do not change the fact that all 4 studies Alan cited either showed an advantage to LC diets for fat loss
Fred, 2 of the papers (Stern & Brinkworth) did NOT show an advantage to LC diets. And you can't just go off means from the studies like you do (as I pointed out in the other post).
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I don't have time to go tit for tat now on your comments to my comments which will result in more tit for tat ad infinitum.
The points made are extremely important, Fred. They show the errors you make statistically, why your assessments of the Stern & Brinkworth papers are not correct, as well as pointing out other important factors you ignore.
Also James, acommon misconception sometimes happens when researchers note "we found no statistically significant difference," which is then translated by others as "they found that there was no difference."
Statistics cannot be used to prove that there is exactly zero difference between two populations.
Simply failing to find evidence that there is a differencedoes not constitute evidence that there is no difference.
This principle is sometimes said as "Absence of evidence is not evidence of absence."
While you say they didn't consume more calories in the Brinkworth study, the fact is they did - the mean is the average calories of the group and at each stage of the trial and they were found to have a higher average total intake than the low-fat group.
It is the only data available since the researchers did not publish the individual data, thus it's the numbers we have to use and can use. In this case, saying they didn't consume more calories because the data, statistically, isn't significant cannot be translated to mean they consumed the same calories - they didn't, that's clear in the numbers. The low-carb group consumed more calories and lost more weight James - period.
Also James, acommon misconception sometimes happens when researchers note "we found no statistically significant difference," which is then translated by others as "they found that there was no difference."
Statistics cannot be used to prove that there is exactly zero difference between two populations.
Simply failing to find evidence that there is a differencedoes not constitute evidence that there is no difference.
This principle is sometimes said as "Absence of evidence is not evidence of absence."
This is all true, Fred.
BUT, this doesn't mean that YOU can turn around and say there IS a difference. To do so is to commit the appeal to ignorance fallacy.
Do you honestly think, in 2 random samples from a population, that the means of those two samples are going to be exactly the same?
Unless your samples are HUGE, of course not.
This is why it is erroneous of you to claim there is a difference. Unless there is evidence of such, you cannot make such a claim.
You are committing confirmation bias because you are stating there is a difference (based solely on means, which is an error), when a difference has not been adequately demonstrated.
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While you say they didn't consume more calories in the Brinkworth study, the fact is they did - the mean is the average calories of the group and at each stage of the trial and they were found to have a higher average total intake than the low-fat group.
Again, Fred, you cannot expect means from two samples to be exactly the same. Unless there is adequate evidence that these samples came from two different populations (which, in this case, there is not), you cannot be making such claims.
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In this case, saying they didn't consume more calories because the data, statistically, isn't significant cannot be translated to mean they consumed the same calories - they didn't, that's clear in the numbers. The low-carb group consumed more calories and lost more weight James - period.
See above, Fred.
Let's say the means were different because one subject at dramatically more than all the others in one group, raising the mean for that group. Would you still be making this assertion, Fred?
Again, Fred, unless you have evidence that these means are different beyond what chance would dictate, you have no case.
Here is a graphic illustration of the problems with Fred's logic and Fred's use of nothing more than means.
Let's take 20 people and divide them into 2 groups. Let's look at their age. Here are the ages for each group:
Group 1:
70, 70, 70, 70, 70, 70, 70, 70, 70, 70
Group 2:
67, 67, 67, 67, 67, 67, 67, 67, 67, 100
The mean for group 1 is 70, and the mean for group 2 is 70.3.
According to Fred's logic, Group 2 is older than group 1, despite the fact that 90% of the subjects are younger.
Granted, this is an overly simplistic example, but it illustrates the point as to why you cannot simply compare two means of two samples. Some sort of statistical analysis is necessary to tell you the probability that the two samples represent different populations.
Fred, 2 of the papers (Stern & Brinkworth) did NOT show an advantage to LC diets. And you can't just go off means from the studies like you do (as I pointed out in the other post).
The points made are extremely important, Fred. They show the errors you make statistically, why your assessments of the Stern & Brinkworth papers are not correct, as well as pointing out other important factors you ignore.
Why do you refuse to address these points?
James - the did you not read my post? I said that the 4 studies either showed no difference or were in favor of low carb. The Brinkworth study showed a greater loss in weight in the LC group and the participants did indeed eat more in the LF group and lost less weight. We can only go by the data presented. They ate more and lost less weight.
In the Stern study the LC group lost more weight and they ate more calories.
I AM correct James - you just can't accept it.
Anyone else here like to give an objective opinon?
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