{"id":195803,"date":"2010-01-18T19:02:56","date_gmt":"2010-01-19T00:02:56","guid":{"rendered":"http:\/\/www.proteinpower.com\/drmike\/?p=3945"},"modified":"2010-01-18T19:02:56","modified_gmt":"2010-01-19T00:02:56","slug":"are-all-diets-the-same","status":"publish","type":"post","link":"https:\/\/mereja.media\/index\/195803","title":{"rendered":"Are all diets the same?"},"content":{"rendered":"

\"\"Synchronicity strikes again.\u00a0 The seeds of this post were sown when Gary Taubes emailed me about a study published in early 2009 in the New England Journal of Medicine<\/em> (NEJM<\/em>) that I had seen at the time, briefly skimmed and tossed aside as worthless.\u00a0 Gary agreed that the study was of little value, but notice that it contained a peculiar statement by the authors, an interesting admission about HDL, the lipophobe\u0092s favorite lipoprotein.\u00a0 And not only had the authors made this strange admission, but so had another prominent lipophobe who wrote the accompanying editorial.<\/p>\n

I pulled the study, read it more thoroughly and still found it mediocre at best.\u00a0 But I did come across the strange HDL statements that Gary had mentioned. (More about which later.)<\/p>\n

As I was shaking my head over the amount of money spent on what was a truly abominable study, the synchronicity occurred.\u00a0 I got a ding that I had a new email.\u00a0 It was a notice from the American Heart Association telling me that this august body had deemed the very study I was holding in my hands as one of the ten most important papers published in 2009.\u00a0 The sheer stupidity of it nearly took my breath away.<\/p>\n

Before we get into the study – which we won\u0092t get into very deeply because, believe me, there\u0092s not much depth – I want to use a parable to show just how silly this study is.<\/p>\n

Let\u0092s set our story in the wonderful country of Stupidland where a debate has been raging about the feeding of dogs.\u00a0 A vociferous old woman who kept dogs had been insisting that different breeds of dogs eat different amounts of food\u00a0 The majority of the populace were of the opinion, however, that all breeds eat the same amount (it is Stupidland, after all) and looked down their noses at those who\u00a0 believe a chihuahua may eat less than a collie.\u00a0 To put an end to the bickering, scientists at Stupidland U ( who were believers in the all-dogs-eat-the-same doctrine) decided to do a definitive study.\u00a0 They went to the Stupidland pound and procured a German Shepherd, a Labrador Retriever, an Irish Setter and an Alaskan Malamute.<\/p>\n

They provided the four dogs with pleasant accommodations and all the food they wanted to eat.\u00a0 The scientists carefully measured every gram of food eaten by each dog and recorded it.\u00a0 At the end of the two year study, they reviewed the data and confirmed what they already suspected to be the case: the different breeds of dogs ate just about the same amount.\u00a0 They did notice one little disparity, however: the larger dogs ate a little more than the smaller dogs, but they were able to correct for that by controlling for size.\u00a0 Their paper proving that different breeds of dogs ate the same amount of food was accepted for publication in one of Stupidland\u0092s most prestigious scientific journals, The Stupidland Journal of Veterinary Medicine.\u00a0 Buried deep within the paper was a sentence few noticed stating that size was a biomarker for food consumption by dogs.<\/p>\n

The Stupidland press picked up on the study and headlines proclaimed that all breeds of dogs eat the same amount.\u00a0 The mainstream Stupidlanders nodded their heads sagely; they, after all, had been right all along.\u00a0 But the old woman, who didn\u0092t actually live within the borders of Stupidland, but who lived close enough to cause trouble, kept insisting that different breeds of dogs didn\u0092t eat the same amounts.\u00a0 She had a beagle and she had a Great Dane, and she had kept careful records of the food consumption of both. She insisted that the Great Dane not only ate more than the beagle, but that it ate a huge amount more. She would bend the ear of anyone who took the time to talk to her, and her data was so persuasive that she was beginning to make converts.\u00a0 Just as the population of Stupidland was once again starting to wonder about the dog breed verses food enigma, the Stupidland Heart Association came out with its annual bulletin announcing that the paper by the brilliant scientists from Stupidland U showing that all breeds of dogs ate the same was the most important paper of the year.\u00a0 The old woman\u0092s first impulse was to attack the Stupidland Heart Association for its sheer stupidity, when suddenly a sense of calmness and clarity settled over her.\u00a0 She experienced a spiritual awakening (just as did the Grinch in another tale) and finally realized the real meaning of Stupidland. She took her dogs and moved far away, leaving the denizens of Stupidland alone to marinate in their stupidity.<\/p>\n

The paper that inspired this parable was published in Feb 2009 in the New England Journal of Medicine<\/em> and titled Comparisons of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates<\/a>.\u00a0 (This is another one of those studies the editors feel is so important that they provide the full text free of charge as a public service.)\u00a0 The authors include Frank Sacks, George Bray, Steven Smith and an entire rogue\u0092s gallery of lipophobes.\u00a0 All the usual suspects, as they say.<\/p>\n

What the NEJM<\/em> study sets out to demonstrate is that different breeds of dogs<\/span> different weight-loss diets of varying macronutrient compositions all bring about the same loss of weight.\u00a0 According to these authors, it doesn\u0092t matter if you go on a low-carb, high-fat diet or a low-fat, high-carb diet, you\u0092ll lose the same amount of weight.\u00a0 Doesn\u0092t matter how the protein, fat and carbohydrate stack up in your weight loss diet, you\u0092re going to lose the same amount of weight.\u00a0 So, you can go to the bookstore, stand by the diet-book shelf, close your eyes and pick.\u00a0 Whatever diet book you end up with won\u0092t matter because you\u0092ll lose the same amount of weight regardless of which one you choose.\u00a0 And, even more importantly – again, according to the authors of this study – whichever diet book you select will help reduce your heart disease risk factors.<\/p>\n

As Dave Barry says: \u0093I AM NOT MAKING THIS UP.\u0094\u00a0 It\u0092s right there in black and white in a study done at Harvard and published in the New England Journal of Medicine<\/em>.<\/p>\n

What\u0092s more, the American Heart Association (AHA) deemed this study to be one of the top ten most important studies published in 2009<\/a>.\u00a0 And they put it #1 on their list.\u00a0 Now they said that they listed these ten studies in no particular order – and you can call my cynical –\u00a0 but I\u0092m just betting that they put this one right at the top for a reason.<\/p>\n

Said the president of the AHA<\/a>, Dr. Clyde W. Yancy<\/p>\n

\n

We all thought the statement made in that study was pretty profound. It really dismissed the notion that there’s something clever about weight loss, [showing] that it really is about calorie consumption or, to make it even more straightforward, portion control. You can spend a lot of time wringing your hands about which diet and the composition of which diet, but it really is a simple equation of calories in and calories out.<\/p>\n<\/blockquote>\n

Give me strength.<\/p>\n

My disgust aside, you may be thinking:\u00a0 Why isn\u0092t the study valid?\u00a0 If they did analyze all those diets and found them to bring about the same results, what\u0092s the problem?<\/p>\n

The problem is that the diets they used in the studies were similar.\u00a0 They didn\u0092t vary all that much in carbohydrate.\u00a0 The diet with the highest carb intake contained 65 percent of calories as carbohydrate while the lowest carb diet was made up of 35 percent.\u00a0 To put this into the gram figures we\u0092re all used to, the highest-carb diet contained 325 gram of carb while the lowest-carb version contained 175 gram of carbohydrate.\u00a0 Now, as those of us who have ever followed a low-carb diet know, 175 gram of carbohydrate does not a low-carb diet make.\u00a0 Granted, it\u0092s lower in carb than the diet with the 65 percent of calories as carb, but it doesn\u0092t even approximate a low-carb diet.\u00a0 As I\u0092ve written before, you\u0092ve got to get the carbs substantially below 100 g per day before good things start happening metabolically.<\/p>\n

What this study has done is to study roughly similar diets for two years and pronounce that all produce about the same results.\u00a0 What the authors (and, apparently the AHA) want you to take away from this study is that real, honest-to-God low-carb diets don\u0092t perform any better than low-fat, high-carb diets.\u00a0 Which, as most of us know from bitter experience, is not the case.<\/p>\n

There are major problems in doing studies such as this one that make their outcomes suspect.\u00a0 And these problems aren\u0092t necessarily the fault of the researchers – they are simply a fact of life.<\/p>\n

When you try to do a dietary study by recruiting people who want to lose weight then randomizing them to a particular diet, you are asking for trouble.\u00a0 If you run the study out over a long period of time – two years, for example, as this study did – you are asking for even more trouble.\u00a0 People go into diets with a lot of enthusiasm and pretty rigorously stick to them at first.\u00a0 But as time goes on, people tend to cheat a little, then cheat a little more and pretty soon find themselves pretty much trending back toward and finally squarely back on whatever their regular diet was before they started the study diet.\u00a0 (Sadly, it\u0092s not just subjects in studies who follow this pattern, but is the fate typical of most dieters.)\u00a0 For this reason, after time, all the people in all the different arms of the study are eating about the same thing.\u00a0 This is why you always see the charts showing weight loss and macronutrient composition start out wildly diverging then converge as the end of the study draws near.\u00a0 In other words, they all end up consuming the same diet, so they all end up with about the same result.<\/p>\n

How can researchers overcome this dismal outcome.\u00a0 Well, you can put out the call for people who really believe in low-carb diets to fill one arm of the study.\u00a0 And recruit people who love the Ornish diet for another, and the Zone for another.\u00a0 These subjects are more likely to stay enthused and stick with their respective regimens for the duration of the study.\u00a0 But then you haven\u0092t randomized your sample and you will be accused of generating worthless data because your sample groups self selected.<\/p>\n

The other way, of course, is to randomize subjects into various diet groups, then put them under lock and key for a year or two and feed them like you would lab animals.\u00a0 Another impractical solution from a cost perspective if in no other reason.<\/p>\n

It\u0092s extremely difficult – virtually impossible, I would say – to conduct accurate studies on diet over a long period of time with a large number of subjects.\u00a0 Consequently, it is nonsensical to rely on the data from such studies to make the case for anything other than how difficult these studies are to carry out.\u00a0 I certainly don\u0092t think for all the reasons above that the study in question merits being listed as one of the top ten studies of 2009 by anyone, much less the AHA.<\/p>\n

In their discussion of this mishmash of questionable data, however, the authors did make a most interesting statement.\u00a0 Almost an admission, if you will, of the superiority of a lower carb diet.\u00a0 This statement is what Gary emailed me about.<\/p>\n

(Before we go on with this, I have to make this aside.\u00a0 HDL and LDL and IDL (intermediate density lipoprotein) and VLDL (very low density lipoprotein) aren\u0092t really cholesterols.\u00a0 Even though we often refer to them as LDL cholesterol and HDL cholesterol, they really aren\u0092t.\u00a0 These different groups of letters refer to transport proteins that carry cholesterol through the blood, not to cholesterol itself.\u00a0 Cholesterol is cholesterol.\u00a0 It is a specific molecule that doesn\u0092t change.\u00a0 Cholesterol is a waxy lipid (fat) that virtually every cell in the body synthesizes (because is it so important).\u00a0 Cholesterol, like all fats, is not soluble in water and therefore can\u0092t dissolve in blood (which is a watery substance), which means that the body has to package cholesterol in a form in which it can be transported from place to place in the blood.\u00a0 The body attaches a specific protein (a lipoprotein) to cholesterol to make it dissolve in the blood.\u00a0 The names LDL, HDL and the rest refer to the specific type of lipoprotein being discussed.)<\/p>\n

Here\u0092s what the authors wrote:<\/p>\n

\n

There was a larger increase from baseline in the HDL cholesterol level, a biomarker for dietary carbohydrate<\/em> [my italics], in the lowest-carbohydrate group than in the highest-carbohydrate group (a difference in the change of 2 mg per deciliter at 2 years)…<\/p>\n<\/blockquote>\n

Even Martijn Katan, a lipophobe if there ever was one, and the author of a number of anti low-carb diatribes that I\u0092ve taken to calling the Katanic Verses<\/a> echoes the same fact – carbohydrates drive HDL down – in an editorial he wrote about the above paper.<\/p>\n

\n

…compliance was assessed with objective biomarkers.<\/p>\n<\/blockquote>\n

\n

The authors used the difference in the change in HDL cholesterol levels between the lowest- and highest-carbohydrate groups to calculate the difference in carbohydrate content between those diets.<\/p>\n<\/blockquote>\n

Now the differences weren\u0092t all that spectacular, but the drop in HDL in those on the higher carb diet was there and noticed by the researchers.<\/p>\n

I find this extremely revelatory because if there is one lipid parameter a lipophobe loves, it\u0092s HDL.\u00a0 And here you have an entire cluster of lipophobes admitting that HDL varies as the inverse of carbohydrate intake.\u00a0 Take any of these folks individually – or, heck, take \u0091em together – and they\u0092ll tell you that low-carb diets are bad because they give you too much fat.\u00a0 Yet they admit that their beloved HDL goes up when carbs go down.\u00a0 Doesn\u0092t make a lot of sense, does it?<\/p>\n

When these folks compared these fairly similar diets they found that all of them reduced the risk for heart disease.\u00a0 They used the fact that HDL went up on the lower-carb diets to deem them heart healthful; and they pronounced the higher-carb diets as heart healthful, too, because the LDL declined on those.<\/p>\n

As Yogi Berra said: \u0093You can observe a lot by just watching.\u0094\u00a0 And they watched LDL go down on the higher-carb diets and HDL go up on lower-carb diets.\u00a0 But the reverse of the Yogi-ism is also true: you can also fail to observe if you don\u0092t watch.<\/p>\n

This refusal to watch is what really gets my dander up.<\/p>\n

The researchers whose names are listed at the top of this paper are all affiliated with prestigious institutions.\u00a0 I am quite sure that there is not a single one of them who is unfamiliar with the work over the last 15 years or so of Ronald Krauss, the researcher who made the discovery of the differences between LDL particle sizes. (The same Krauss, by the way, who published the paper about the meta-analysis of saturated fat and heart disease<\/a> much in the blogosphere currently.) Krauss and his team showed that large, fluffy LDL particles aren\u0092t particularly harmful whereas the small, dense LDL particles are the ones that cause the problems.\u00a0 He also discovered that increasing carbohydrate in the diet caused LDL to shift to a smaller, denser pattern while decreasing carb and adding fat made LDL change to the larger, fluffier non-problematic kind.\u00a0 (You can read a nice review of LDL particle size in this article<\/a> published in the popular press.)<\/p>\n

If you reduce carbs and add fat to the diet, not only does your HDL go up, but your LDL makes a particle size change for the better.\u00a0 However, when you increase carbs and reduce fat, your HDL goes down and your LDL goes down too, but it changes for the worse. So even though the high-carb, low-fat diet decreases LDL, it doesn\u0092t decrease risk – it increases it because even though LDL is lower, it is made up of a dangerous particle size,which negates any possible value of the fall in LDL.\u00a0 All of these researchers know this.<\/p>\n

Why didn\u0092t they check LDL particle size on these subjects?\u00a0 Had they done that, they would have found that those subjects on the higher carb diets would have lowered their HDLs and althought they lower levels, would have shifted to more of the dangerous, smaller, denser LDL particles.\u00a0 They couldn\u0092t have then made the case that not only did all diets work the same where weight loss was concerned but they all decreased heart disease risk.\u00a0 They would have had to say that although all diets brought about the same degree of weight loss, the lower-carb diets clearly reduced the risk factors for heart disease the most.\u00a0 And that\u0092s an admission I suspect they didn\u0092t want to make. Therefore they refused to observe.<\/p>\n

I don\u0092t know what the deal is with these folks.\u00a0 Why don\u0092t they simply tell it as it is?\u00a0 Do the long-term lipophobes who have ridiculed low-carb diets for years and built their careers on the rickety edifice of the low-fat diet not want to admit they were wrong? That\u0092s understandable, I suppose, but what about the young ones?\u00a0 Why are they stampeding over the low-fat cliff like Gadarene swine?\u00a0 Do the younger lipophobes not want to offend the older ones?\u00a0 Why do they fail to reconcile their theories with what amounts to basic biochemistry and physiology?\u00a0 Whatever the reason, they are fighting a losing battle.\u00a0 Ultimately the truth will out and when it does, all these people who have tenaciously clung to the low-fat, high-carb fantasy will be – like the phrenologists and other failed theorists of the past –\u00a0 so much detritus in the history of medicine.\u00a0 And their books and papers will be displayed as curiosities of the boneheaded thinking of an earlier day. A sad but fitting fate.<\/p>\n

Photo: Set of phrenological heads, England\u00a0 circa 1831
\nvia The Pollo Web<\/a><\/p>\n

\n<\/img><\/a>\n<\/div>\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Synchronicity strikes again.\u00a0 The seeds of this post were sown when Gary Taubes emailed me about a study published in early 2009 in the New England Journal of Medicine (NEJM) that I had seen at the time, briefly skimmed and tossed aside as worthless.\u00a0 Gary agreed that the study was of little value, but notice […]<\/p>\n","protected":false},"author":108,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-195803","post","type-post","status-publish","format-standard","hentry","category-news"],"_links":{"self":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/posts\/195803","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/users\/108"}],"replies":[{"embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/comments?post=195803"}],"version-history":[{"count":0,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/posts\/195803\/revisions"}],"wp:attachment":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/media?parent=195803"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/categories?post=195803"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/tags?post=195803"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}