Dr. Lustig Schools A Dietitian

      55 Comments on Dr. Lustig Schools A Dietitian

A reader sent me a link to an interview with Dr. Robert Lustig, telling me that a registered dietitian called into the show to explain how it’s all about low-fat diets and calories in/calories out, which prompted Lustig to slap her down.

I listened to the entire interview, but if you only have time to enjoy hearing a dietitian put in her place, skip ahead to about 47 minutes in.  You can listen to the interview here.


55 thoughts on “Dr. Lustig Schools A Dietitian

  1. js290

    I’ll ask again: Are the biochemical reactions that Lustig presents incorrect? If the biochemical reactions are correct and that fructose reduces ATP production, stimulates DNL, and disrupts hormonal signaling, then that’s compelling enough to limit, if not all out avoid, any form of fructose. Whether there’s any studies that show fructose is especially addicting is not particularly interesting to me.

    I also agree with Dr. Feinman that all carbs are probably a problem. He’s not the only person advocating this position. Given there are no essential carbohydrates and that fat produces more ATP than glucose, limiting high glycemic carbs (processed or not) may also be a prudent thing to do.

    If you’re going to attack Lustig, at least go after the biochemistry he presents because ultimately that’s where the rubber hits the road. Him focusing on fructose doesn’t really take away from the glucose intolerance paradigm. I’m not sure I’d would criticize him just because he wasn’t advocating *my* message.

    My thoughts exactly. Attacking Lustig because he focuses on sugar is a bit like attacking Dr. Davis because he focuses on wheat.

  2. Ken

    @js290, sorry I did not see your earlier query addressing me the last time I was reading. I see that Richard Feinman has (effectively) responded in my stead, and much more competently and authoritatively than could I.
    I did not say that Lustig’s “biochem reactions”, as presented variously, were incorrect (although I COULD make quite a few criticisms). I wrote what I wrote — my comments stand on their own, I think, pretty well (or do you think that ethanol IS actually a carbohydrate?). I have listened and read a lot of Lustig’s public presentations, interviews, and so forth (and this is where the rubber meets the road for me — if Lustig matters, it is in the public policy domain). I could list a lot of simple facts that he has presented that are wrong — exaggerations, distortions, and so forth. I GAVE a couple of examples, and I could probably list at least a dozen more if I went back and reviewed all of his stuff that I alluded to above. None of the simple facts were biochem reactions — they were SIMPLE! I am a professional in a scientific field, and I have done several years of personal study of the research in certain fields relating to health, and I know a BSer when I see (or hear) one. Lustig is, partially, trying to blow things by his lay audience. I think he is sincere, and I agree with a lot of what he has to say. That does not excuse his methods, his lack of accuracy in making presentations, and so forth in trying to influence public policy. I think that Richard Feinman was making a similar point in referring to Lustig as the Ancel Keys of sugar, no? Keys was sure he had the solution, and so is Lustig — why wait for “all the evidence to come in”?, as McGovern said. You seemed to accept Feinman’s criticism of Lustig without objection. Feinman’s objections are little different from my own.
    Human metabolism is very complex, and poorly understood, and very difficult to study (that is one of many reasons animal models are employed). If one does not by now understand the principle that the science must be thorough and precise, at the very least, before building government policy on it then one has not done much homework. I HAVE done some. I have had some personal reasons to do so.
    The Canadian researcher who came on in the middle of the NPR interview expressed a reaction to Lustig’s claims that fructose is unique that has been almost universal — he was not the first nor second nor third. I understand what he is talking about — I have heard and read it before, in more detail, from others. Fructose is NOT unique nor toxic — it’s just one form of carb acting as a carb metabolically, just as Feinman asserted, as far as any research has so far demonstrated.
    I guess I should leave it to the pro’s in the appropriate fields to counter Lustig on more elaborate technical grounds. But none of the pro’s were successful in stopping Keys. And Lustig is making his pitch to the public, quite obviously (e.g. 60 Minutes). I am a member of said public at large, and in that context I am not buying what he is selling.
    By the way, js290, do you not think that glucose “stimulates DNL”? Do you not think that glucose can, and does, “disrupt hormone signaling”? Hence should we restrict all dietary starches as well as sugar via governmental intervention? Lustig wouldn’t LIKE THAT:) Do you get my point? None of this is at all “compelling” — you need to develop some more skepticism and develop some more knowledge before swallowing Lustig’s sweeping conclusions hook, line and sinker IMO.
    Don’t get me wrong — I think that dietary sugar is to be avoided, especially in excess (whatever this might be for any individual at any given time). And it is a big part of the overall problem — no doubt — because it is in various forms of sweet drinks and refined foods of all sorts that are cheap, available and increasingly heavily consumed. It is a large percentage of the calories consumed typically in the US today, as Eric Oliver pointed out in Fathead.
    And I wrote in my last comment that I DO think Lustig’s assertions are more correct as applied to young children (his actual field of work) than as applied to adults.
    But there are different approaches to mitigating the problem than Lustig’s. I like Tom’s better (e.g. Fathead, and the one likely point of agreement with Spurlock), for example. In other words, bottom up. I am tired of being dictated to by moronic, corrupt policy created by self-interested ne’er-do-well’s and enforced via “your government” and its trickle-down commercial and institutional hangers-on.

  3. Ken

    P.S. After listening to and reading links to Experimental Biology 2012 in San Diego (thanks much to David Gillespie), I see much pushback “from the pro’s”. Good.
    Two quick points that immediately occur to me in reaction to a summary of Lustig’s talk at this conference (addressing the only two items cited in the Despain summary that I read):
    1. Lustig made his usual implication using “beer belly” and “sugar belly”, which seems to be intended to support his ethanol-fructose analogy. Fine, but historically (going back to Peter Mayes, whose writings and thoughts on fructose Taubes cites and I find much more compelling, to Peter Cleave, and also further back) I believe that it has been the maltose (in beer) that has been associated with the belly by many, if not all, astute and competent observers and thinkers. Distilled liquor (lacking the carb calories but having more ethanol calories) has been around for a long time, but we don’t hear of a “whiskey belly”, do we?
    2. Lustig makes an argument (again, only by implication) that the much higher glycation factor of fructose vs. glucose implies that it is more toxic via AGEs. But I am sure he is aware that neither glucose nor the other (dietary) monosaccharides appear to be direct major contributors to the tissue AGE burden in actual analysis. The main contributor is believed to be methylglyoxal, a major glycolytic metabolite (according to my reading — I think this is uncontroversial). Lustig emphasizes the presumably evolved preference for dominantly hepatic metabolism of fructose in comparison to glucose (and this might be nature’s way of dealing with the high glycation factor, as I already suggested). Glycolysis is tied to glucose (not fructose), and is commonly present in almost every cell. One cannot have things both ways (once metabolized in the liver, fructose is eliminated as a potential glycator in the whole-body tissues) — I find Lustig’s implications intentionally deceptive. He is “cheating” in his arguments, and this has been my reaction at least once every time I have read or heard him in public debate. The “experts” may recognize this, but most may not I fear.
    3. Ah, thankfully I see that George Bray made an appearance at the same conference, somewhat buttressing my early speculation about Lustig’s possible association with him. This is, admittedly, just a guess. But the two are certainly singing from the same hymnbook.

    Tom, sorry for being so lengthy in my arguments on your blog. I am not as concise a presenter as Lustig (lacking his “excellent style”:), but the devil’s in the details as they say. You seem much more sympathetic to Lustig than I, but methinks that insistence upon accuracy is one crucially important element in these matters lest we have another Keys->diet->statins-for-everyone fiasco. Once the pro’s are restrained by fear of a Kilmer McCully fate they will mostly stay silent, and so early on is the right time to “attack” the likes of Lustig IMO.

    No apologies necessary. I appreciate the lengthy and thoughtful reply, and I’m sure other readers do as well.

  4. js290

    Here’s what I believe: per carbon atom, fatty acids produce more ATP than glucose. Therefore, fat had to be the more optimal evolutionary fuel. If the Randle Hypothesis is correct, then the preference would be to avoid dietary glucose so as to continue using fat for fuel. Even if the Randle Hypothesis is incorrect, we’re fairly certain of glucose’s effect on insulin response, and we’re fairly certain of insulin’s role in inhibiting lipolysis.

    So far, Lustig hasn’t presented any information that discourage me from seeking fat as my primary fuel source. What he’s done for me is made me more aware of the amount of sugar that’s been made available to be consumed relative to a hunter-gatherer evolutionary past. And, Lustig’s critics haven’t really said that he’s so wrong that excess fructose actually promotes lipolysis and health.

    Difference between Lustig and Keys is Lustig is in the information era. There are no gatekeepers of information. We take the good (biochemistry) with the bad (presentation style). And, we’re able to make the best choices based on all available information.

  5. Mike G

    I realize I’m late to this discussion, but did you point out Lustig’s mistake involving “fructose 1,6 bis-phosphate?” In his “Sugar: The Bitter Truth” presentation, he stated that “here’s one thing fructose does that glucose doesn’t…” And then he goes on about fructose’s supposedly unique ability to promote fat production in the liver. When I showed my students this part of the presentation, one of them pulled out the handout on “glycolysis” that I’d given them the day before. Then he asked, “Mr. G, doesn’t glucose produce fructose 1,6 bis-phosphate during glycolysis?” And I said “Yes it does! Good job for pointing that out!” Thus, glucose can indeed contribute to lipogenesis in the liver, just as fructose does. It also stimulates lipogenesis in adipose tissue, while inhibiting lipolysis. Lustig skips over these pathways, as if they don’t exist. Nonsense! Perhaps his message is good for public policy, but I agree that the science presented should be correct.


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