HD on Boundless Health Podcast…Again


I love talking to Dr. Bret Scher, Preventive Cardiologist extraordinaire and host of the Boundless Health Podcast.  He recently had me on his show for the third time and – as usual – this was a wide-ranging conversation.  I wonder if he’ll continue to invite me, as he’s been killing it with some A-list guests recently.  Not sure exactly where I fit into that mix, but for now, I’m happy to chat with him whenever called upon.

Allow me to tempt you with just a few of the topics we explore in this episode:

  • My (early) personal experience with time restricted feeding (TRF) and what I hope to gain.
  • What I think about non-physician engineers like Dave Feldman and Ivor Cummins (both recently interviewed on the BH Podcast – you should definitely listen to these) tackling cholesterol and glucose metabolism, respectively, from novel angles.
  • The problem with making the ketogenic diet the “standard of care” for diabetes.
  • Why I think that smart people are stupid about their healthcare.

You can access the episode by searching for the Boundless Health Podcast using your favorite podcast app, you can click on this, or if you don’t like that, you can click here.  One of the methods should get you there.  As always, feel free to come back and comment after listening.  Enjoy!

By reading this site, listening to the podcast, and/or interacting with me in the Comments, you agree to abide by my Disclaimer.


14 Replies to “HD on Boundless Health Podcast…Again”

  1. Interesting podcast. I would caution you not to fall too far down the Insulin fairy/LCHF/fasting, rabbit hole for which Dr. Scher seems to have grabbed a pom pom. LCHF has been around for over a hundred years and is reinvented by the latest salesmen/guru’s every 10 years or so.

    Most obesity experts agree on two things for LONG TERM healthy weight management – real food and adherence. The second is key, if you don’t enjoy your life while you’re losing the weight, its coming back on.
    Its astounding how many smart people think that lowering insulin is required for weight loss, while completely ignoring the insulinogenic effects of protein (whey, beef, etc). Tim Noakes is an example of a brilliant man who is now seeing science through his own personal conformational bias

    Evidence based nutrition and lifestyle advice is ridiculously boring and does a lousy job of selling books and driving sales.
    – Eat real foods, mostly plants
    – Get adequate sleep/improve sleep hygiene
    – Move more, find something you enjoy, be consistent, weight bearing activity is also very important.
    – Be part of a community, laugh, be social, take vacations, etc.
    – Find a physician, nurse, or dietician to help keep you accountable and provide guidance.

    Oh, and if you’re still looking to bulk up, eat more. You’re welcome.

    1. Crusty, I love the way you think (and the way you write), and we agree on most points you make about diet and lifestyle. I can’t speak for Dr. Scher, though I think it’s fair to say he is more enthusiastic in general about the LCHF approach to food than I am. However, I like the ketogenic diet for diabetics, if they find it sustainable, as the improvement in glycemic control, weight, and other metabolic parameters can be truly impressive in a very short period of time (a la the Virta Health data). Though diabetic people could achieve similar results through a more measured and balanced approach to diet, the problem is they just don’t – in my world, at least. I do think there is something unique about cutting out starches in the diet that truly cuts cravings for more of said starches and sugars, and helps break a cycle of overfeeding for many folks who can stick with the KD.

      I don’t think I’m in danger of falling too far down the rabbit hole, but then again, it’s hard to be objective about oneself, so I promise to be careful! As you heard on the podcast, I am midway through a 3-month self-experiment with time-restricted feeding, not to lose weight, but to perhaps improve insulin sensitivity and increase autophagy. How helpful has it been for me? I don’t know yet, but I like the medical journal data I’ve read so far, which is why I decided to try it. One thing I have found, now that I’ve kind of figured out how to get enough calories in on fasting days: not eating breakfast has completely knocked out the major hunger I used to have mid-morning, which feels liberating. Could I have achieved the same result by eliminating all starch and fruit from breakfast and eating pure protein and vegetables? Probably, but time is limited on work days and I don’t always have time to cook a protein and vegetables. So I think I may continue TRF long-term, but we’ll see!

      In any case, I love your sensible approach to wellness. Thanks for the comment.

  2. Hi Crusty. I appreciate your comments, especially about the evidence based nutrition and lifestyle advice. That is exactly what I wrote my book about, Your Best Health Ever. And you’re right. That advice does not sell a lot of books! No question you are correct in the core principals of sustainable health. The fascinating part comes in when people are already insulin resistant and metabolically unhealthy. For some of them, a ketogenic diet may be the best solution, at least to help them overcome their metabolic syndrome/insulin resistance/diabetes, and then they will do much better on a real foods diet after that. I am a strong believer that everyone is an individual. For some of those individuals, KD is a great way to go. For some it is not. But at a minimum, I believe a LCHF/KD needs to be part of the medical conversation. One more tool in the tool kit. Thanks again for your comment.

    1. Bret, I agree that the KD can be a useful tool in the tool kit. However, I do worry about diabetics using it for awhile and then trying to transition back to a less restrictive eating strategy. My concern is that they will have been “treating” their IR, but not “curing” or “overcoming” it. So when they try to eat more starch, even healthier starch, they will find that they are back in a cycle of hyperinsulinemia and back on the path toward hyperglycemia and diabetic complications. So while I am not advocating that all diabetics eat ketogenically (I believe they will fail), I am saying that the ones who do should probably try to stick with it long-term, perhaps just building in some “cheat” days or weeks into each year, so they can still enjoy a beautiful baguette every now and then.

      1. Agreed! I think the word “cure” is an interesting one, and maybe “in remission” is better. The tendency to become insulin resistant or even full blown diabetic will likely always be there. It can be kept in check with lifestyle, but not sure we can think of it the same way we can cure an ear infection. Great point!

    2. Hi Dr. Scher. I did read (and enjoy) your book as recommended by HD. I also enjoy your podcasts.
      I agree that LCHF is a tool to be used as appropriate and ideally recommended by knowledgeable professionals. As far as I know, we still don’t have any long term data, or population studies on health outcomes for individuals who have followed a KD/LCHF diet for decades. We have an animal model that seems to imply a potential age accelerating effect of a high protein diet (MTOR pathway, IGF-1). I’m concerned when i see patients putting butter or MCT oil in their coffee, have bacon wrapped steak for breakfast, yet exhibit real fear around eating a handful of carrots, a tomato, or a mandarin orange.

      HD, I’m also very intrigue by the potential effect of TRF on increasing autophagy. I feel its a valid strategy for potential health optimization (versus disease treatment).
      I spent 5 years working in an integrative cancer centre (which, as you can imagine HD, led me to massively dislike alternative medicine). Fear sells, A LOT. The one think that i will share anecdotally (with some ongoing clinical trials to potentially support this), I found a significant decrease in chemotherapy side effects achieved via TRF/fasting 24-72hrs. I collected over a hundred case reports that one day I should get around to writing up.

      The Virta Health group publication is interesting. I would have preferred to see a longer duration study, a control group, and the research carried out by individuals not directly tied to Virta Health. In many regards it reads somewhat like the magic joint formula ads that are in my local Thursday flyer, sounds too good to be true, but you still can’t help but call the 1-888 number. I don’t have a horse in the diet race but at least this study was longer, and published in a respectable journal. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677007/ .

      Thanks for the discussion.


      1. Hi Crusty. Great comments. The protein issue is a fascinating one. The main difference between KD and Atkins is that KD is (or at least is “supposed” to be) low carb, high fat, moderate protein, where as Atkins was high fat and high protein. Obviously everyone does it differently, but I agree with you. Keeping up with the veggies, minimizing all other carbs, liberalizing the fat, and maintaining moderate protein seems like the best template. But we are all individuals and thus the approach will vary.

      2. Hi Crusty, (and hi Bret and HD)

        First, I have a horse in the diet race as I’m a physician for Virta. I did want to address a couple of your valid criticisms of the research.

        I believe your comment is referring to our 10 week data, but since then we have published 1 year trial data in the journal “Diabetes Therapy” https://link.springer.com/article/10.1007%2Fs13300-018-0373-9 The one year data published data on the control arm of the study and included respected outside authors Anne Peters, MD and Wayne Campbell, PhD . In addition, most patients in the trial are past 2 years now, and we will be publishing 2 year results in the near future. Beyond that, the trial has been extended to 5 years in order to address the concerns about long-term results.

        In addition, UCSF recently published a small 1-year RCT using a ketogenic diet for diabetes with good results. https://www.nature.com/articles/s41387-017-0006-9

        The ketogenic diet isn’t for everyone, and there is a lot of bad information out there. However, there is some good emerging data showing this approach is very effective in the right patients.

  3. Hey HD et al,

    Just listened to this podcast (I had quite the podcast backlog) and thought I’d pass along this one by Dr. Dan Pardi and Dr. Stephan Guyenet where they discuss the Virta Health 1-year data. Was a very balanced analysis of what can be taken away from the study.

    There was also a study published a bit earlier this month (the DIETFITS trial) that may also peak your interest and tied into some of the podcast topics. I wrote up an in-depth analysis over here: https://examine.com/nutrition/low-fat-vs-low-carb-for-weight-loss/

    All that aside, I wanted to talk about Ivor Cummins and some of his work. I’d heard of him from around the interwebs before but finally decided to look him up since it got mentioned on the podcast. I ended up reading through the first section of his new book, Eat Rich, Live Long, on Amazon and some of his blog posts. There were a number of items that made me very hesitant and a bit skeptical of the accuracy of his work. I’ll try to be brief in discussing them!

    This is the first thing that jumped out at me in the book as it was mentioned in the podcast as well. Cummins misrepresents the work of Keys by repeating an inaccurate claim about his work – that it was cherry-picked. This claim has been passed around so many times in low-carb circles that it now seems to be accepted as fact. A recent 60-page white paper was put out that debunked the following claims in an attempt to set the historical record straight:

    1. Countries were selected and excluded based on the desired outcome.
    2. France was purposefully excluded
    3. Dietary data in Greece taken during Lent introduced a distortion.
    4. Sugar was not considered as a possible contributor to coronary heart disease.

    Brief write-up and full text here:

    A second claim I saw in the book is another popular low-carb talking point: that John Yudkin was right all along about sugar and his research was ignored. This also does not accurately reflect the historical record. Yudkin’s work not ignored, but was often of a lesser methodological quality. Other labs actually tried to replicate some of his studies and could not reproduce his findings. You can read an analysis of his work at these two links.


    Last point! The PURE Study (http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)32252-3/fulltext)
    In Cummins book, he presents a very superficial and misleading interpretation of the PURE study results (claiming that saturated fat was vindicated and carbs have finally been fingered as the real dietary culprit). This is not what the study conclusions were and bypassed any discussion of the limitations of the study or where it sits in the entire body of evidence on the topic. Two in-depth analyses here:


    I’ll stop at those comments, but from viewing his work thus far it seems that Ivor has developed a very sophisticated but selective/incomplete interpretation of the literature.

    I know I’ve thrown a lot of links and info at you and I know you may not be able to get through them (only so many hours in a day!) But I hope that you find some of this useful.

    Thanks for letting me write a mini-novella on here. Looking forward to the next podcast. I hope you can discuss some of your n=1 results by then, very interested in how it turned out for you!

    1. Michael, it took me awhile to read through all those links, but they were quite enlightening, thank you. I was especially wow’d by the extended remix-version of the clarification of Ancel Keys’ work. On the surface, it would seem that some of the talking points being promulgated by the low-carb/high-fat community can be easily refuted.

      As you seem to be more heavily into this space than I am, with respect to reading blogs and such, I’d be interested whether – to the best of your knowledge – the authors of these various articles have a strong dietary bias. In other words, are the folks writing this stuff well-recognized vegans or anti-keto people? If they are known to be fairly agnostic in the low-carb vs low-fat debate, that would make their work even more powerful.

      1. Hey HD,

        Thanks for taking the time to look through these links – glad you found them interesting!

        To answer your question, neither The Nutrition Wonk (Katherine MSc, RDN, LDN) nor Nutrevolve (Kevin C. Klatt PhD(c)) have strong dietary leanings (neither are anti-keto/low-carb, nor are they pro-vegan/low-fat, etc), Both are very much interested in science communication and evidence-based information.

        The white paper that Katherine wrote about Ancel Keys was commissioned by the True Health Initiative (http://www.truehealthinitiative.org/) but she nor any of the other authors received any compensation for the paper and she was only approached because she had previously done independent research on Keys.

        This was the original article where she wrote about Keys (https://www.thenutritionwonk.com/single-post/2016/04/13/Ancel-Keys-and-the-Seven-Country-Study-A-Response-to-The-Sugar-Conspiracy). It was in response to a sensationalist and poorly researched article written in the Guardian (https://www.theguardian.com/society/2016/apr/07/the-sugar-conspiracy-robert-lustig-john-yudkin)

        Hope all this helps! Thanks again.

  4. Hi Michael. Thank you for your very thoughtful and detailed reply. I will try to briefly add my two-cents on the subjects you brought up.

    I wrote about The DIETFITS study here:

    To cut to the punchline, the “low carb” group was really a moderate carb group at 130grams per day. Much lower than the standard American diet, but much higher than a true low carb, ketogenic diet which is usually less than 30grams or at most 50 grams per day. But the conclusion we can all agree on is that if you cut out junk and focus on real food, you will lose weight. Amen to that.

    I also wrote about the PURE study here:

    The take home: It’s an observational trial and proves nothing. But any observational trial that shows no association between saturated fat and mortality adds more fuel to the argument against other observational trial that suggest there is a correlation. Which, by the way, there are very few that show an association with overall mortality. I highly recommend reading work done by Zoe Harcombe who did her PhD on this topic. http://www.zoeharcombe.com

    As for the Seven Countries Study, there is solid debate on both sides about what Ancel Keys knew ahead of time or not. But I think that argument detracts from the main fault of his study. It was an observational trial that could not and did not control for all the variables that could impact the cardiovascular risk far beyond what people ate. In addition, it woefully fails to meet the Bradford Hill criteria for causation in an observational study (https://www.edwardtufte.com/tufte/hill). So, we can debate all we want about the specifics of the study, but at the end of the day, it is poor quality science that should not have near the attention or influence that it has generated.

    I hope that helps explain my opinion, and how I feel we need to put the studies in perspective before drawing any sweeping conclusions from them. And I definitely agree that I can’t wait to hear more about HD’s N=1 experiment!

    1. To piggyback on your thoughts, Bret…I would agree that we have to interpret observational trials cautiously when it comes to establishing causation. However, based on what I’ve read thus far about Keys’ work, I don’t know that I would characterize it as poor quality science. I’d say it has significant limitations, but as observational studies go, it seems to me like the investigators did a pretty thorough job.

      I guess what bugs me about any end-of-the-spectrum group, whether we’re talking LCHF or LFHC (vegan), the tendency to solidify one’s position happens first, then the trumpeting of supporting data (regardless of quality) and ridiculing of contrary data (regardless of quality) happens second. All these people who claim to be “scientists” and “truth seekers” are deceiving themselves, IMHO, as they do not appear open to data that contradicts their deeply held beliefs.

      I think it’s fine to say “LCHF makes sense to me and I’m going to live my life that way.” But since we truly don’t know where the data will ultimately sort out with respect to effects on heart disease and mortality, let’s at least leave the door open to the possibility that the ketogenic style of eating may ultimately prove to have some serious, negative consequences. Do I think it’s great for diabetes? Sure. Can I recommend it with no reservations whatsoever to someone with a history of ASCVD? No, I think the jury is still out on that.

      Me, I’m gonna eat my veggies, fresh fruit, meat, chicken, fish, plain greek yogurt, and…that absolutely delicious, crusty baguette they give me with the charcuterie plate at the little French dive I love. You know, a balanced diet.

    2. Hey Bret,

      Thanks for taking the time to read through this. I’ll take these in order.


      So I read through your analysis, and I think I can help clarify some things about the study. So for the definition of “low-carb”, here are the definitions proposed by a group of prominent low-carb scientists and advocates (Eric Westman, Richard Feinman, Jeff Volek, Stephen Phinney, and others):

      – Less than 20–50 grams per day: very-low-carb ketogenic diet (VLCKD) or low-carb ketogenic diet (LCKD)
      – 50–150 grams per day: low-carbohydrate diet (LCD)


      These ranges have been similarly echoed in other publications, which provide a general scientific consensus on these definitions. So, while the low-carb group in this study was not ketogenic, they were still consuming enough carbs to be classified as low-carb.


      I know that the Diet Doctor uses different cutoff points to define this, but these are somewhat arbitrarily chosen. The studies above (especially those from the low-carb scientists) put forth their rationale and explanations as to why their cutoff points have been selected.

      The second important point was that DIETFITS was not a test of a ketogenic diet, never claimed to be, and was never intended to be (The study was pre-registered and the methods can be found here https://www.ncbi.nlm.nih.gov/pubmed/28027950).

      Given the data we do have from both tightly controlled ward studies (which test the actual diet) (https://www.ncbi.nlm.nih.gov/pubmed/28193517) and free-living studies (which test the diet prescription) (https://www.ncbi.nlm.nih.gov/pubmed/25182101 & https://www.ncbi.nlm.nih.gov/pubmed/23651522) there’s no reason to believe a keto diet would have performed better than a low-carb diet (or the low-fat diet) in the DIETFITS cohort.

      There’s a multi-part series going on at this blog reviewing the evidence for a keto diet if you’re interested in reading more (Disclosure – I helped review the Hunger one):

      How the Ketogenic Diet Affects Hunger (Research Review) • Sci-Fit

      How Carbs and Protein Affect Ketosis (Keto Research Review) • Sci-Fit

      The Ketogenic Diet’s Impact on Body Fat, Muscle Mass, Strength, and Endurance • Sci-Fit


      So if you haven’t had the chance, the two links I posted in my OG post on this study are worth reading though. They both do an in-depth analysis and give appropriate context.

      My thoughts on saturated fat are pretty well summed up here (lots of good nuance in this discussion). Tl;dr: saying saturated fat is categorically bad is just as unsupported as saying saturated fat is categorically harmless/good. There’s evidence for nuance here and the food-context in which you are consuming saturated fat matters greatly.


      I did actively follow Harbcombs’ work for about a year (I’m also actively following or have followed these low-carb advocates for between 1 – 2.5 years: Tim Noakes, Robert Lustig, Dave Asprey, Gary Taubes, Tom Naughton, Jimmy Moore, Robb Wolf, Andreas Eenfeldt/Diet Doctor, Chris Kresser, Nina Teicholz, Mark Sisson, and Sam Felton)

      I’m very familiar with the common arguments they put forth and the studies they typically use to back up these claims. But when you trace their citations back to the original study or go looking for other data in the area’s they discuss you start to notice a trend. They all tend to suffer from the same pitfalls:

      – Presenting evidence out of context or without context
      – Over-extrapolating study results
      – Downplay the limitations of the studies that support their narrative
      – Play up the limitations of the studies that challenge their narrative
      – Do not take into account the entirety of a given topic / cherry-picking

      In regard to Harcombe, I recall her attempting to make a case in one blog post that fruit consumption (due to its sugar content) had played a role in the obesity epidemic and that we should be eating less of it (none of this is supported by the data we have). Her bias for low-carb (she does, after all, make money from advocating this position) shows in her published work as well (For example the meta-analysis she published a while back (http://openheart.bmj.com/content/2/1/e000196 that was well-critiqued here http://nutrevolve.blogspot.com/2015/02/beware-meta-analysis-fat-guidelines-and.html)

      What troubles me is that they are taking the same reductionist public health recommendations (Carbs/sugar are bad! Fat is good!) that were seen, on the opposite end of the coin, in the 80-90’s (Fat/saturated fat is bad! Carbs are good!). We have already seen a reduction and flatlining of sugar consumption in the US and fat intake has crept up. Obesity rates continue to rise.

      I think that there is some hindsight bias when it comes to the SCS. It’s easy to judge a study with the benefit of 40+ years more knowledge, but what these studies added to the scientific literature needs to be put in the context of what data was available at the time.

      The SCS was an incredibly rigorous observational trial for its time (and still actually holds up well today, if you read through their methods). That is part of the reason why it was given such influence in its day. Keep in mind that this was a time where statistical models were not regularly applied to published scientific papers at the time, leading to more bias in the data. The SCS did run statistical analyses (a big feat given the data set size and lack of computing power at the time). Contrast this with some of Yudkin’s work, which presented raw data and ran no statistical tests.

      The Bradford Hill criteria can be used as a good guide for observational studies but should not be the end-all, as there are some limitations in his criteria when applying them to epidemiology (bigger convo for another time).

      I really don’t think we need to be talking about this study much either. The only reason it keeps coming up is that Ancel Keys and his work gets vilified by the LC community. So it is necessary to set the historical and scientific record straight.

      One tidbit that gets obscured in this discussion is that Ancel Keys was actually the father of the modern Mediterranean Diet. He even wrote a book on it!

      Also worth a read is the original 1980s US dietary guidelines (it’s a short read). I think it may surprise you:


      I know that 60-page white paper on SCS I linked to in the OG comment was a long one, but here’s an abbreviated version worth reading if you have time. The SCS was not poor quality science – it was a well-conducted observational study with limitations that had to be considered within the scope of the evidence at the time:


      Thanks for the dialogue, hope some of this provided clarity.

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