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#11
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Low-carb and Mediterranean diets beat low-fat for weight-loss,lipid changes at two years
HbA1c
LoFat 0.4% Med 0.5% LoCarb 0.9% fBG (1 yr, 2 yr mg/dL) LoFat Med -23.6, -32.8 LoCarb -18.1, 1.2 *But why the reduction of HbA1c behaved differently from fasting plasma glucose and HOMA-IR, so that it was larger in low-carb group than in the Med group, is a mystery to me, too. *Perhaps people familiar with diabetes could have some kind of explanation or speculation about this? Is it possible that a low-carb diet shifts cellular machinery towards efficient fat metab, decreasing carb metab efficiency, thus increasing insulin resistance. I'm not sure if HOMA takes this into account. Ideally, insulin resistance should be tested after all three groups are returned to a reference diet at the end of trials. An improved cholestrol profile and Hb1Ac may not relate to improved fBG and IR due to additional factors. For example, loCarb will likely give lower HbA1c. But loCarb is higher in lipophilic toxins (ie PCBs, dixions, etc). TCDD, a potent dioxin, increases mito ROS. Cellular ROS is likely to increase insulin resistance. Lipophilic toxins are highest in animal, fish, dairy & egg fats. [TCDD decreases ATP levels and increases reactive oxygen production through changes in mitochondrial F(0)F(1)-ATP synthase and ubiquinone.] Mitochondria generate ATP and participate in signal transduction and cellular pathology and/or cell death. TCDD (2,3,7,8-tetrachlorodibenzo- p-dioxin) decreases hepatic ATP levels and generates mitochondrial oxidative DNA damage, which is exacerbated by increasing mitochondrial glutathione redox state and by inner membrane hyperpolarization. This study identifies mitochondrial targets of TCDD that initiate and sustain reactive oxygen production and decreased ATP levels. One week after treating mice with TCDD, liver ubiquinone (Q) levels were significantly decreased, while rates of succinoxidase and Q-cytochrome c oxidoreductase activities were increased. However, the expected increase in Q reduction state following TCDD treatment did not occur; instead, Q was more oxidized. These results could be explained by an ATP synthase defect, a premise supported by the unusual finding that TCDD lowers ATP/O ratios without concomitant changes in respiratory control ratios. Such results suggest either a futile cycle in ATP synthesis, or hydrolysis of newly synthesized ATP prior to release. The TCDD-mediated decrease in Q, concomitant with an increase in respiration, increases complex 3 redox cycling. This acts in concert with glutathione to increase membrane potential and reactive oxygen production. The proposed defect in ATP synthase explains both the greater respiratory rates and the lower tissue ATP levels. PMID: 17109908 |
#12
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Low-carb and Mediterranean diets beat low-fat for weight-loss, lipid changes at two years
"Doug Freyburger" wrote (2) the Atkins Foundation
funded the study. This is both valid and invalid at the same time. True. However, it is interesting to note that Doc McDougall bitched for years that Dr. Atkins made a lot of money off his diet plan, but never did any research. Now that the Atkins organization funds a study, he won't accept the results! The gray in my hair saw about 5 years worth of set back in its advance. Wow! Now that is one I never saw. How nice! Yeah. Eating veggies is the low carb way. Strange how that worked out. Strange enough that people who have never tried low carb don't think it's a feature of the system. Yeah. I loved veggies as a kid, but I don't find them very appealing as part of a fat-free, high-starch meal. I like my olive oil sautees with a sliced clove or 2 of garlic thrown in before the veggies. In fact that is what I had for dinner. A huge panful of broccoli sauteed in olive oil and garlic, then pepper jack cheese and eggs stirred in and cooked. Salt and red pepper flakes to taste. Yum. My whole family loves broccoli. My grandson expects it whenever he is here for dinner. My new puppy... the first food he ever tried to steal and eat from a grocery bag carelessly left on the floor... yep, broccoli. I give him little sprigs of the raw stuff whenever I have it. He inhales it. Hannah |
#13
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Low-carb and Mediterranean diets beat low-fat for weight-loss,lipid changes at two years
jay wrote:
HbA1c LoFat 0.4% Med 0.5% LoCarb 0.9% fBG (1 yr, 2 yr mg/dL) LoFat Med -23.6, -32.8 LoCarb -18.1, 1.2 But why the reduction of HbA1c behaved differently from fasting plasma glucose and HOMA-IR, so that it was larger in low-carb group than in the Med group, is a mystery to me, too. Perhaps people familiar with diabetes could have some kind of explanation or speculation about this? . . . . I read in one report that the low carb group started out at 20 grams of carb (with a focus on vegetable sources of protein and fat) and increased their intake over the two years to around 110 grams. It sounds like, toward the end of the study, that the low-carb and Med diets might have been fairly similar. I can't figure out what these people would be eating if they were minimizing/abstaining from meat, cheese, eggs, etc. Israel is in the Middle East. Surely, a Mediterranean style diet is closest to what they would normally eat and most would probably aim as close to what they would be traditionally eating as the confines of their diet group allowed. At 110 grams, they could work in beans, pasta, many wheat-based dishes, etc. I think that trying to solve the "mystery" of the results is probably hopeless. Kind of a "What Did They Eat? And When Did They Eat It?" conundrum. |
#14
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Low-carb and Mediterranean diets beat low-fat for weight-loss,lipid changes at two years
"Hannah Gruen" wrote:
"Doug Freyburger" wrote: The gray in my hair saw about 5 years worth of set back in its advance. Wow! Now that is one I never saw. How nice! It's a fairly common complaint that 6 months into a very successful loss phase hair falls out. It's not as common to come back later to report it ended up coming back in thicker or less gray or whatever. Yet that's what usually happens. But it's easier to come asking about a problem than to come back several months later to report on the long term result. |
#15
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Low-carb and Mediterranean diets beat low-fat for weight-loss, lipid changes at two years
"Cookie Cutter" wrote I read in one report that the low carb group started out at 20 grams of carb (with a focus on vegetable sources of protein and fat) and increased their intake over the two years to around 110 grams. It sounds like, toward the end of the study, that the low-carb and Med diets might have been fairly similar. I can't figure out what these people would be eating if they were minimizing/abstaining from meat, cheese, eggs, etc. Israel is in the Middle East. Surely, a Mediterranean style diet is closest to what they would normally eat and most would probably aim as close to what they would be traditionally eating as the confines of their diet group allowed. At 110 grams, they could work in beans, pasta, many wheat-based dishes, etc. I think that trying to solve the "mystery" of the results is probably hopeless. Kind of a "What Did They Eat? And When Did They Eat It?" conundrum. Yes, I've been reading more about this one, too. Even more puzzling (to me) is the fact that the calories were restricted for the low-fat and Mediterranean diet groups, but not for the LC group. My guess would be that as the LC group started adding back carbs, they lost the natural appetite suppresant function of the diet and calories may have increased? Not sure, as I haven't read the full study or perused the data. If total calories in is substantially different for the different groups, that can make a difference in findings that may trump effects of macronutrient diet makeup. At any rate, it seems like it would have been a good idea to keep as many parameters as possible equivalent, if they wanted to compare diets. Like calories, for instance. Sometimes I read these research designs, and wonder who on earth reviewed and approved them. They just defy logic. Anyway, it's just not a well-designed study, IMO, even if it does show advantage for the lower-carb plans (no surprise there.) HG |
#16
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Low-carb and Mediterranean diets beat low-fat for weight-loss,lipid changes at two years
Hannah Gruen wrote:
"Cookie Cutter" wrote I read in one report that the low carb group started out at 20 grams of carb (with a focus on vegetable sources of protein and fat) and increased their intake over the two years to around 110 grams. It sounds like, toward the end of the study, that the low-carb and Med diets might have been fairly similar. I can't figure out what these people would be eating if they were minimizing/abstaining from meat, cheese, eggs, etc. Israel is in the Middle East. Surely, a Mediterranean style diet is closest to what they would normally eat and most would probably aim as close to what they would be traditionally eating as the confines of their diet group allowed. At 110 grams, they could work in beans, pasta, many wheat-based dishes, etc. I think that trying to solve the "mystery" of the results is probably hopeless. Kind of a "What Did They Eat? And When Did They Eat It?" conundrum. Yes, I've been reading more about this one, too. Even more puzzling (to me) is the fact that the calories were restricted for the low-fat and Mediterranean diet groups, but not for the LC group. I think that the idea was that higher protein adn fat consumption and lower carb consumption of LC diet suppresses appetite so that LC group kind of automatically and voluntarily reduces its calories. It seems to have also worked that way. My guess would be that as the LC group started adding back carbs, they lost the natural appetite suppresant function of the diet and calories may have increased? Not sure, as I haven't read the full study or perused the data. If total calories in is substantially different for the different groups, that can make a difference in findings that may trump effects of macronutrient diet makeup. If you look at Table 2. Changes in Dietary Intake, Energy Expenditure, and Urinary Ketones during 2 Years of Intervention http://content.nejm.org/cgi/content/full/359/3/229/T2 you'll see that calorie reductions in LC and LF groups were almost identical. In the Mediterranean group the reductions were a little smaller, but still not statistically significantly different from LC and LF groups. At any rate, it seems like it would have been a good idea to keep as many parameters as possible equivalent, if they wanted to compare diets. Like calories, for instance. As I mentioned, the realized calorie reductions were not statistically significantly different between groups, and in LC and LF groups they were almost identical. Sometimes I read these research designs, and wonder who on earth reviewed and approved them. They just defy logic. Anyway, it's just not a well-designed study, IMO, even if it does show advantage for the lower-carb plans (no surprise there.) I have to disagree with you. Although not completely without flaws, this is, however, a large, long term (2 years), well-designed and well-published (NEJM) study, which compared well-designed and well-known diets. Additionally, if it wasn't well-designed, it probably wouldn't have been published in NEJM, the number one medical journal in the world. Here's an interesting excerpt from Low-fat Diets May Not Be Best For Weight Loss, Study Suggests http://www.sciencedaily.com/releases/2008/07/080716171134.htm : "Dr. Iris Shai is a researcher at the S. Daniel Abraham International Center for Health and Nutrition in the Department of Epidemiology at Ben-Gurion University of the Negev. She conceived the study with Dr. Stampfer, the senior author, while she was a Fulbright fellow at Harvard School of Public Health and Channing Laboratory in Boston, Massachusetts." Dr. Meir Stampfer is one of the authors of the study in question and a very remarkable scientist. Harvard's press release HSPH Department Chairs Meir Stampfer and Walter Willett Most Cited Scientists of the Decade in Clinical Medicine Harvard School of Public Health Press Release, Friday, September 23, 2005 http://www.hsph.harvard.edu/press/releases/press09232005.html from September 23, 2005, writes about him as follows: "Meir Stampfer, Chair of the Department of Epidemiology at the Harvard School of Public Health (HSPH) has been ranked the number one most cited scientist in clinical medicine for the last decade. According to ISI Essential Science Indicators, 376 of his published research findings were cited nearly 31,000 times between 1995 and August of 2005." Dr. Stampfer's web page at Harvard: Meir Stampfer Professor of Nutrition and Epidemiology Department of Epidemiology Department of Nutrition http://www.hsph.harvard.edu/faculty/meir-stampfer/ I wonder, if a major force like Stampfer would have allowed his name to be used in this study, if there were any doubts about its quality. -- Matti Narkia http://ma.gnolia.com/groups/Nutrition |
#17
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Low-carb and Mediterranean diets beat low-fat for weight-loss, lipid changes at two years
On 2008-07-21, Matti Narkia wrote:
Hannah Gruen wrote: Anyway, it's just not a well-designed study, IMO, even if it does show advantage for the lower-carb plans (no surprise there.) I have to disagree with you. Although not completely without flaws, this is, however, a large, long term (2 years), well-designed and well-published (NEJM) study, which compared well-designed and well-known diets. Additionally, if it wasn't well-designed, it probably wouldn't have been published in NEJM, the number one medical journal in the world. Here's an interesting excerpt from Low-fat Diets May Not Be Best For Weight Loss, Study Suggests http://www.sciencedaily.com/releases/2008/07/080716171134.htm : "Dr. Iris Shai is a researcher at the S. Daniel Abraham International Center for Health and Nutrition in the Department of Epidemiology at Ben-Gurion University of the Negev. She conceived the study with Dr. Stampfer, the senior author, while she was a Fulbright fellow at Harvard School of Public Health and Channing Laboratory in Boston, Massachusetts." The reason this study was conducted and published is simply because it's the type of thing which can attract media attention these days. The institutions behind it become visible in the act of doing something regarding a large problem which faces the general public. It's nothing more than a circus show, of absolutely no consequence. It's poor science, but it doesn't appear dishonest. That is to say, as long as no data was falsified, no reputations are going to be damaged by this type of thing. Dr. Meir Stampfer is one of the authors of the study in question and a very remarkable scientist. Harvard's press release Maybe Stampfer is so confident in his credentials, that he no longer gives a damn. If he wants to do a little bit of fun, unscientific pig farming, he can boldly attach his name to it without scathing his reputation. HSPH Department Chairs Meir Stampfer and Walter Willett Most Cited Scientists of the Decade in Clinical Medicine Harvard School of Public Health Press Release, Friday, September 23, 2005 http://www.hsph.harvard.edu/press/releases/press09232005.html from September 23, 2005, writes about him as follows: "Meir Stampfer, Chair of the Department of Epidemiology at the Harvard School of Public Health (HSPH) has been ranked the number one most cited scientist in clinical medicine for the last decade. According to ISI Essential Science Indicators, 376 of his published research findings were cited nearly 31,000 times between 1995 and August of 2005." In science, people cut-and-paste citations from other papers, without even /reading/ the original papers that are being cited! Do you know that misspellings in citations propagate among unrelated papers from different authors? The more citations you have in your paper, the more it seems that you have done a thorough job of covering the prior research. There is a pressure to cite, which leads to padded citations lists. A citation is not always positive. There are citations which are used to exemplify lesser quality prior work. If you include such a citation, it gives you an opportunity to extend your paper by a paragraphs of text which does nothing but criticize the earlier work, and explain how the new work improves on it. The choice of citation can also be influenced by the degree to which the cited researcher confirms a hypothesis which the new researcher is trying to argue. If your paper argues that unlimited amounts of energy can be obtained from a perpetually moving machine, a significant fraction of your citations will be to other crackpot papers. |
#18
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Low-carb and Mediterranean diets beat low-fat for weight-loss, lipid changes at two years
"Doug Freyburger" wrote in message ... "Hannah Gruen" wrote: "Doug Freyburger" wrote: The gray in my hair saw about 5 years worth of set back in its advance. Wow! Now that is one I never saw. How nice! It's a fairly common complaint that 6 months into a very successful loss phase hair falls out. It's not as common to come back later to report it ended up coming back in thicker or less gray or whatever. Yet that's what usually happens. But it's easier to come asking about a problem than to come back several months later to report on the long term result. Yes, true. Well, and younger people without much or any gray in their hair won't have any change of course. But this is the first time I recall hearing anyone note lessening of the gray from LC. Cool. BTW, I recall reading way in the past that increasing certain B vitamins can sometimes reverse premature graying. I know you're like me - much healthier, high-nutrient-density fare since starting LC. I can say I virtually never get sick any more. I'm not sure to attribute that to LC (I think that is part of it) or to the fact that I started supplementing with higher doese of Vitamin D. Probably both. HG |
#19
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Low-carb and Mediterranean diets beat low-fat for weight-loss, lipid changes at two years
"Matti Narkia" wrote
I think that the idea was that higher protein adn fat consumption and lower carb consumption of LC diet suppresses appetite so that LC group kind of automatically and voluntarily reduces its calories. It seems to have also worked that way. Matti I am going to defer to you on this one, more or less. From reading your posts over the years, it's clear you know a lot more about this stuff than do I. However, from a non-biological scientist POV, it makes absolutely no logical sense to me to set up a study in which calories are controlled in only 2 of 3 groups. Yes, as it turned out the group that was not controlled for calories ended up eating the same amount as the other groups. But what if it hadn't? Why take that chance? I don't get it. Table 2. Changes in Dietary Intake, Energy Expenditure, and Urinary Ketones during 2 Years of Intervention http://content.nejm.org/cgi/content/full/359/3/229/T2 you'll see that calorie reductions in LC and LF groups were almost identical. In the Mediterranean group the reductions were a little smaller, but still not statistically significantly different from LC and LF groups. Again, since I assume that appetite reduction was not one of the parameters being studied here, why not just control all groups? I have to disagree with you. Although not completely without flaws, this is, however, a large, long term (2 years), well-designed and well-published (NEJM) study, which compared well-designed and well-known diets. Additionally, if it wasn't well-designed, it probably wouldn't have been published in NEJM, the number one medical journal in the world. Well, if you say so. I have, however, noted quite a bit of carping on various blogs of people who really are (unlike me) experts at this stuff. I'm not going to argue that the results are not interesting or valid, however. Here's an interesting excerpt from Low-fat Diets May Not Be Best For Weight Loss, Study Suggests http://www.sciencedaily.com/releases/2008/07/080716171134.htm : I think appeals from authority are a bit weak. And yet, I did just that (above). I know some of the criticism has revolved around the fact that none of the 3 diets tested were done in a way that satisfied all proponents of such diets. LC had too many carbs. LF wasn't low enough. Etc. Overall it seems to have been a reasonable effort, but had caloric intake differed substantially from group to group, that would have been a different story, wouldn't it have? Why take that chance? HG |
#20
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Low-carb and Mediterranean diets beat low-fat for weight-loss,lipid changes at two years
"Hannah Gruen" wrote:
... I know some of the criticism has revolved around the fact that none of the 3 diets tested were done in a way that satisfied all proponents of such diets. Thinking about this since it came out I've ended up at a different vewpoint than my initial reaction. The low carb group ended up at 120 grams per day after a couple of months at 20. That's not a weight loss diet at all. In fact for me it isn't even a maintenance level. But there are plenty of people who do have 120 as a maintenance level. LC had too many carbs. LF wasn't low enough. Etc. Since the LC group was a maintenance group, I don't think the intent was to compare loss phases at all. I think the intent was to compare the impact of the maintenace phases on long term health. Since the experiement lasted 2 years it was too long for just doing loss phases for any of the plans. Given the experiment is about the maintenance phase (inferred but not mentioned in the abstract) the fact that there was an average loss on all of the plan types is nice but irrelevant. I'd want to know what percentage regained not what the mean value is. Since it's not about loss all the mean value means is the ones with net loss out numbered the ones with net gain, and it was number of pounds in each direction that got out numbered not number of subjects. Being a comparison of the maintenance phases, the health markers other than average loss are all more important results. Overall it seems to have been a reasonable effort, but had caloric intake differed substantially from group to group, that would have been a different story, wouldn't it have? There is precedent from prior studies that LC groups do not get instruction to reduce total calories by LF groups do. Neither of us agrees with that precedent but that precedent seems to be the source for it. Why take that chance? I wonder about encouraging low carbers to cut total calories. I think about posters to ASDLC over the years - Some have wanted to use the appetite suppression of ketosis to drive their calorie intake levels down to starvation levels with minimum or no discomfort. I would certainly hesitate to push a group of low carbers to reduce calories if I were in charge of an experiment in fear of harming someone with an eating disorder I hadn't detected. |
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