• I’m asking for your help, on obesity, for TIE

    I finished reading The Big Fat Surprise by Nina Tiecholz over the weekend. I found a lot of it to be compelling. It raised a lot of questions about the research behind out current strategies for nutrition, weight loss, and the prevention of heart disease that I’d like to discuss here on the blog. I still need to wrap my head around some of the studies and what questions I’d like to consider. I’ve also reached out to the author, who graciously agreed to talk to me when I’ve got my ducks in a row.

    To that end, I’d be interested in hearing from those of you why may have read the book. What did you think? I’d really like to hear from those of you who disagreed with it. Have you read any well-reasoned critiques you find compelling? Please tell me where to find them.

    I’m going to open up comments on this post, and all the posts on this thread. there will be ground rules, and comments that don’t follow them won’t be approved.

    Here are the rules for this post:

    1. Comments must be focused on the research and evidence in the book. I don’t want to hear what you thought about the prose, the style, etc.
    2. Critiques must be reasoned. I’ve read some diatribes against the book, and I’m not interested in those. Same goes for supportive reviews.
    3. Appeals to authority will be ignored.
    4. Anything off topic will not be approved.

    I’ll start us off with a question of my own. Studies on the Diabetes Prevention Program found that “losing weight through regular physical activity and a diet low in fat and calories” can significantly reduce the risk of developing type 2 diabetes. The DPP was a large RCT, yet its findings were not in the book. I know it had only one diet arm, but I would have preferred it acknowledged. Why not?

    Comments open! If you prefer, tweet at me here instead.

    @aaronecarroll

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    • As a Family Physician practicing for over 20 years with a special interest in obesity and weight loss I would say that I share your feelings trying to get our heads around all of this 180 degree change. I started practice in the early 90s and preached the low fat Ornish style method for years. I used the phen/fen combination successfully until the meds were withdrawn. Personally I have journeyed through my own experience with vegetarianism and fat phobia. When I was a vegetarian I developed fatty liver and elevated liver enzymes. My personal experience is that this resolved when I changed to a low carb approach. I have no clinical trial to point to but in my personal experience and that of working closely with patients for over 20 years, the only method that has consistently worked for patients and myself is a low carb/low glycemic diet. When we see data like you reference regarding other approaches reducing diabetic risk I think the difficult thing to tease out of the data is the effect of the diet change itself vs. the effect of the weight loss achieved. The key thing that makes the low carb diet most appealing to me is that we have a plausible physiologic explanation for its effectiveness that we lack for other approaches. Insulin levels correlate directly with obesity. Insulin may even be pro-carcinogenic at high levels. It all comes back to reducing insulin surges and total insulin levels. If a patient loses weight by any means the insulin levels should drop as well and insulin resistance should be reduced. The problem is that caloric restriction doesn’t work. The body is not a simple furnace and calories in vs. calories out does not take the hormonal controls into consideration. I believe that the good science, not just epidemiology which can never prove cause and effect, but controlled studies looking at surrogate markers like lipid parameters and insulin levels will continue to validate the low carb and high fat approach. This is how I now counsel my patients and if they can make the changes required we are seeing good results. Still, “unlearning” not to say “eat plenty of fruits and vegetables, low fat dairy and lean protein” which I have said for many years is hard.

    • Addressing your question, it’s hard to say, although my suspicion is that Ms. Tiecholz doesn’t really disagree with the conclusion of the studies. The problem is that the “energy in/energy out” paradigm of weight control is sort of like saying that gravity causes airplane crashes – true, but it really doesn’t reveal much. Obesity is a complicated problem with few simple answers. That’s why books such as Ms. Tiecholz’s and initiatives such as Taubes and Attia’s NuSi venture are so important in promoting better education of the hormonal and biochemical underpinnings of obesity.

    • Have you read this article by Dr. David Katz? He’s an obesity researcher. I think he presents a compelling case against the fat-is-back hype (at least as it relates to one study). It may give you some ideas as you try to wrap your head around things.

      • I did read his, but I wished he’d responded more to the scientific issues and made less of an appeal to authority.

    • I can’t answer why the DPP was not discussed in the book, but I notice it is often omitted in reviews or books about weight loss studies. Perhaps this is because in the DPP weight loss was not the primary outcome. Weight loss and regular physical activity were behavioral goals to prevent type 2 diabetes. I am disappointed to see that it is often overlooked.

      Also, just a point of clarification. The DPP did not have a “diet arm”. The intensive lifestyle intervention arm (ILI) had the goals of modest weight loss (5% loss from baseline) and regular moderate intensity physical activity (150 minutes per week of activity similar to brisk walking). To achieve the weight loss goal participants were counseled to adopt a low fat diet and used self-monitoring by counting fat grams to achieve that goal. Calorie counting was part of a toolbox of strategies for participants not achieving adequate weight loss through monitoring fat grams.

      Sorry if I am being pedantic by contesting the use of the term diet arm, but I want to avoid confusion with other weight loss studies that compare the efficacy or effectiveness of strategies like diet only to exercise only.

    • In her recent book Death by Food Pyramid, Denise Minger, who has given a very cogent rebuttal to The China Study, raises the issue from her take on the data that the perceived problem with saturated fat may be only when it is associated with a high level of sugar at the same time. This might actually make sense physiologically for those of us who are beginning to think of sugar, fructose especially, as a pro-inflammatory marker. Could high levels of saturated fat in the diet be benign relatively speaking in a diet that is low in carbohydrates but also be a confounding risk factor in a diet that is high in carbohydrates? Though she is not trained in nutrition she is trained in statistics and seems to take a very even handed look at the data.

    • It is one thing to write an interesting book that tells us we do not know as much as we like to pretend.
      The temptation is then to say, “And the real correct answer is….” I think the author may have succumbed to this temptation.
      Why do we know so little about the effect of diet?
      1) Maybe we can do an RCT on diet, but I do not know of any that are double blind. So there is not going to be any grade A evidence.
      2) Even double-blind RCTs have trouble with behavioral responses. If you lose weight, you may change your physical activity even though this is not an intervention in the trial.
      3) One behavioral response is to substitute foods that give similar satisfaction to those which are reduced or eliminated in the intervention arm of a study. Since diet and physiology are linked, we are introducing all sorts of effects into our studies.
      4) And long term may be very different from short term. Only regimens that are easy and satisfying are likely to result in any lasting health effects.
      5) The interesting data coming out on the effects of gut flora and our cultivation of gut flora via carnitine just shows how complex the link may be between diet and health. There may be other systems in there that interact with our diet.
      6) Dietary interventions may have different effects depending on when in a person’s life cycle they are introduced.
      So, we don’t know much.
      But we are pretty sure moderate exercise is a good thing. We just don’t know how to sell it. And we really do not know how it interacts with diet.

      I do not find “The Big Fat Secret” all that surprising as a phenomenon. People seem to pay a lot more attention to diet than they did 50 years ago, but we are a lot fatter. Someone was going to write a book pointing out that what we are doing is not working.

    • Been trying to figure out if it is worth my while to read the book so that I am officially qualified to comment on it. One thing that I wonder in all of these discussions of diet and exercise is how much they measure theory (or tightly controlled experimental conditions) and how much they measure practice, and perhaps a diet that is inferior in theory but still better than nothing would do better in practice because it is easier to stick to it — that is, bacon is tastier than oatmeal. There could be a psychological effect at work, too — if I eat oatmeal for breakfast, don’t I deserve a reward for my virtue, whereas if I had bacon, well, I had bacon for breakfast.

      (What do I do? Exercise, lots of it. I ride my bike to work and for errands at least 50 miles each week; at my size and the bike’s size, probably 2500 extra calories burned every seven days. Utility biking means that the time for biking does double duty for exercise and transportation. This seems to work for me — I lost a little weight and kept it off for years now, and the blood chemistry got better — and studies suggest a nice reduction in mortality risk, but for 99% of the population in this country this particular approach does not work.)

    • Low carb diets do appear to be effective in reducing weight and the associated weight loss is accompanied by favorable changes in surrogate markers such as LDL cholesterol, CRP and insulin levels (1), BUT, low carb diets are also associated with an increase in overall mortality (2), and as an anecdote, Dr. Robert Atkins, proponent of the low carb Atkins diet did suffer a serious MI albeit at age 72.

      Taxes may be an effective way to reduce junk calorie consumption (3) and certainly have been very effective tools in tobacco and alcohol public health. By contrast, it is very difficult to demonstrate success through personal level interventions in any of these areas. In times of tight budgets, “sin taxes” also have the advantage of being revenue positive.

      1) http://jama.jamanetwork.com/article.aspx?articleid=200094

      2) http://annals.org/article.aspx?articleid=746013

      3) http://www.nytimes.com/2014/06/02/business/study-examines-efficacy-of-taxes-on-sugary-drinks.html?_r=0

    • Dr. Carroll,

      Sorry to say I haven’t read this book specifically. However my wife spent most of a year researching this topic for her MPH thesis during med school. The focus of her thesis was what the research suggests about how doctors should treat obesity.

      You can read her thesis in full here: http://obesitystigma.info/Obesity_Stigma_Thesis.pdf

      If you would be interested in talking to her about her research (for example all the other studies she read that didn’t make it into the paper) she is always happy to chat about this topic.

      Good luck,
      Benjamin