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Podcast with Dr Paul Saladino (2)

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Part two is up, mostly about the glycerophosphate shuttle...


Peter
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tuck
366 days ago
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Part II with Peter from Hyperlipid.
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2020 Barkley Fall Classic

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Training for the BFC can be interesting — you often don’t know if you are in or not until just a few weeks out. The race fills quickly, and there is always a long wait list (which is where I seem to find myself each year). Last year I got the notification from Laz 24 days from race day. This year, with Covid, there was a slight indication the race may happen in late July — for prior finishers only, so I thought that might give me a good chance.

As race date got closer, we found that Laz was able to get permission to host 125 runners, to start in waves of 25, 15 minutes apart. The pool of prior finishers from the US, that wanted in, was in the 110 range, and Laz filled out the remaining spots with other well qualified runners — people who have finished a loop at Big Barkley, or who had finished other long/tough races.

Covid also changed pre-race activities – no packet pick up the day before, no lunch at the Warden’s table studying maps, etc. Instead, we would get maps race morning — roughly 30-45 minutes before our wave was to start! I ended up in the third wave based on my prior finish times.

Kelly and I made our way from NC over to Frozen Head, driving the van, stopping in Black Mountain for pizza, and then heading to the park. We had a spot in Flat Fork, but got word from another racer that her spot in Big Cove would be open as she couldn’t make it, and we opted for that. Parking the van in a relatively flat spot closer to the bathroom was much better than the primitive camp site with port-o-pot at Flat Fork. When we arrived a Frozen Head, we ran into THE Keith Dunn at the ranger station, and we made few purchases from the shop, before going to our site. We relaxed there a bit before heading to the Mexican place for dinner.

(A side note on Covid — we were quite amazed at the differences between NC and TN on mask wearing. At the grocery store in TN, maybe 10-15% of people had on masks. At the foyer of the restaurant, no one did, other than Kelly and I!!)

Anyway, race morning came, and we drove out of the park a couple miles to pick up race packets and the maps. We pulled over so I could review them before heading to the race start. I looked at it all and thought “oh, that looks easy, not anything new that we haven’t seen.” But then, after another minute or two, I noticed the “blue loop.” Hmm, loop, what could that be? It then hit me that the shirt I had just gotten that said “double your pleasure, double your fun, two, two, two rats in one,” and the double mint gum that came in the pack, meant something! Two climbs of rat jaw!

Rat Jaw is literally the hardest mile I have ever done. 2000′ in just over a mile, much of it a bushwhack through saw briers, some of it more like a bear crawl than a hike/walk (there is no running on the Rat). In the past it has taken me around an hour and fifteen minutes to make it to the top. And this year, we’d get to do it twice! Double your fun!

So we drove to the start area, and literally I had 10 or 15 minutes before my wave was set to go. I made my final gear adjustments… Another covid note — this year there would only be water on the course. No food — so you had to carry all your own calories and other gear you thought you might need. I had asked about poles, and the answer was “no, but there are plenty of sticks on the course!” So, my pack had all my food, a fair bit of water which I could top off on the way, a light, and not much else.

I won’t describe the course any further, I’ll just share pictures. I finished in about 10.5 hours, 37th out of the ~110 starters, but 3rd in my new age category of 50+ (which is not an official category, but I did have to check!)

Photos of Kelly and I at the famous yellow gate the day before the race:

Race start:

Testicle Spectacle – the smirk on my face on the 3rd shot is because I had way too much speed on my “butt slide” technique and was about to slide off into the woods!

Summiting Rat the 1st time — I had actually caught the front of the pack — there were about 25-30 of us, with the lead group of 3-4 bushwhacking, so we caught them. I thought about bushwhacking up to help, but figured it was better to save a little energy and wait.

The bottom of Rat just before starting the 2nd climb:

And the 2nd summit of Rat:

I’d note that both Rat Jaw climbs took about an hour this year, roughly 15 minutes faster than in prior years. Most of that had to be the much cooler temps — probably a good 15F cooler!

And finally, the finish:

Another great day at Frozen Head. A lot of suffering, but a lot of smiles too. I love this race, and if I could do just this and Uhwarrie 40 every year, I’d be a pretty happy runner. 🙂

I would say that lack of run volume again caught up with me in the end — runing 10 hours/30 miles/12k’ on 15-20 mpw is not ideal. I was strong on the climbs, due to all the ascending done this year, but my feet and legs were pretty shot coming down Chimney the last few miles.

Gear: Soloman Ultra Sense (or some such), Ruhn compression shorts, icebreaker sleeveless, Stio collared, injinji toe socks, big leather garden gloves, UD pack.

Food: lots of tailwind, some vFuels, part of a bar, and some granola chews. Oh, and sushi! I had the idea to grab a California roll at the grocery store the day before, and carry that in my pack. Ate them 1st before anything else so they would no sit out too long. I would not do this on a hot year, but the cooler temps meant they would keep well.



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tuck
372 days ago
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The 2020 Dietary Guidelines Committee: Who Will Stand Up for Rigorous Science Over Industry Interests and—really?—Religion?

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2020-DGA-Committee.jpg

By The Nutrition Coalition

USDA-HHS finally announced the members of the advisory committee for the 2020 Dietary Guidelines, a powerful group of experts who will determine what constitutes a healthy diet. Their work has implications not only for nutrition and health in the United States but is likely to influence food policy globally.

In its educational efforts, The Nutrition Coalition (TNC) emphasized the need for the committee to include top experts in “evidence-based” medicine. These are scientists who know how to properly prioritize scientific evidence and could help bring a much-needed scientific foundation to the Dietary Guidelines. (A “lack of scientific rigor” in the Guidelines was noted by the National Academies of Sciences, Engineering, and Medicine, or NASEM, in a 2017 Congressionally mandated report to review the guidelines process). Such experts could also create some distance between the committee and the established interests who inevitably shape the Guidelines—from Big Food and Big Pharma, to scientists entangled in various conflicts of interest.

Towards this end, TNC especially promoted the candidacy of Stanford professor John Ioannidis, arguably the world’s top expert in evidence-based policy, who was nominated by the entire editorial board of the prestigious American Journal of Clinical Nutrition. Should anyone doubt his qualifications, take a moment to download the 200+ page “short version” of his CV and note that, among his hundreds of publications and awards, he has virtually no conflicts of interest.

Rather than Ioannidis or another, similar top expert who was nominated, however, USDA-HHS named a committee member who represents the very opposite of evidence-based medicine: a religiously-motivated researcher following a belief system that the vegetarian diet is part of God’s divine will. Indeed, while dismissing the application of Ioannidis, one of the most respected, highly awarded, and highly cited scientists in the world, USDA-HHS instead chose a promoter of the doctrine of the Seventh Day Adventist Church.

Joan Sabaté

Joan Sabaté

Joan SabatĂ© is Chair of the Nutrition Department at the Seventh Day Adventist institution, Loma Linda University. He teaches the vegetarian doctrine as part of the church’s “Health Ministry” offerings, and has written a long paper about the various “successes” of the church in spreading its dietary beliefs worldwide. In both his research, outreach, and educational activities—including serving as chairperson of the International Congress on Vegetarian Nutrition, hosted every 5 years by Loma Linda University—SabatĂ© has devoted his career to the promotion of the vegetarian diet.

What is religion doing in the Guidelines? Conflicts of interest come in many forms—financial, non-financial, professional, etc.—but a religious conflict of interest, because it is among the most deeply held of beliefs, may be the strongest. There can be no argument that this kind of ideology should not be informing population-wide public policy.

Major Conflicts of Interest with Big Food and Big Pharma

In addition to his religious beliefs, SabatĂ© has numerous financial conflicts of interest, having accepted funding from the Almond Board of California, the National Pecan Shellers Association, the International Tree Nut Council Nutrition Research and Education Foundation, and the “nut, soya, and avocado growers” generally, in addition to multiple grants from both the National Peanut Board, and the California Walnut Commission.

It would be unfair to single out Sabaté for financial conflicts of interest, however.

Jamy Ard

Jamy Ard

Jamy Ard, for example, of Wake Forest University, has long been extremely close to the food giant NestlĂ©. Since 2009, he has served as the Medical Director for Nestlé’s Optifast, a food-replacement supplement, and he is pictured virtually as a company employee on the company’s website. Ard also serves on Nestlé’s advisory board and has received $431,883 from NestlĂ© to study Optifast. Indeed, Ard has served on the advisory boards of several pharmaceutical companies, all of which make drugs targeted at nutrition-related diseases. These include Arena Pharmaceuticals, Novo Nordisk, Japanese global giant Eisai, and Vivus, which makes the weight-loss drug Qsymia.

Steve Heymsfield of the Pennington Biomedical Research Center, meanwhile, was for years the Global Director of Scientific Affairs and Obesity at Merck and has also served on advisory boards for other pharmaceutical companies, including the Tanita corporation, which sells devices to measure obesity, and Medifast, a competitor to Optifast, the maker of meal-replacement shakes.

Barbara Schneeman

Barbara Schneeman

Barbara Schneeman of U.C. Davis served as president of the Dannon Institute, founded by the eponymous yogurt-maker, and has also been funded by the potato industry. She has served as a trustee and was funded by the International Life Sciences Institute (ILSI), a group supported entirely by giant food and chemical companies such as Coca-Cola and Monsanto. Other committee members funded by or consulting to ILSI include Teresa Davis, Jamy Ard, Regan Baily, Ronald Kleinman, and Elizabeth Mayer-Davis.

Nearly all the committee members have a long list of conflicts of interest with food, pharmaceutical, or supplement companies. The NASEM, in its review of the Guidelines’ process, had recommended disclosing and managing these conflicts of interest, yet USDA-HHS rejected these recommendations.

The Nutrition Coalition will be working on filling this gap by cataloguing the conflicts of committee members and will be reaching out to them for their help in ensuring full disclosure of any potential conflict of interest that might influence the development of the Guidelines. It is our hope that knowing such conflicts will help, as NASEM intended, the committee to better manage them.

Another Strike Against Evidence-Based Policy

The Nutrition Coalition supported Ioannidis’s candidacy principally because he has written and spoken extensively about the need to reduce our reliance on biased science in the creation of nutrition policy. He has particularly emphasized that epidemiology is an especially weak type of science which therefore invites bias in its interpretation. Among other things, epidemiology cannot, in the vast majority of cases, establish cause and effect. Unfortunately, this very same epidemiology has long been used as the foundation for much of our Dietary Guidelines—leading to serious reversals in recommendations, such as the 2015 elimination of caps on cholesterol and the end of the formal “low-fat” diet recommendation. These two longstanding pieces of dietary advice were founded upon an excessive trust in epidemiological findings and were only reversed when the science supporting them could not be confirmed by more rigorous clinical trials.

It is therefore problematic that 11 out of 20 of committee members either work or have been trained in the field of epidemiology.[1] TNC hopes that they will understand the limitations of this data and the value in giving primacy to the more rigorous data from clinical trials on humans, especially when that data contradicts the epidemiological/observational findings.

Some Promising New Viewpoints on the Committee

To USDA’s credit, the agency fulfilled a pledge it made last fall to encourage “fresh points of view” on the committee, by “including members with varying points of view on the topics and questions to be examined.” 

For example, appointee Lydia Bazzano of Tulane University is the first-ever committee member with at least some research background that includes low-carbohydrate diets, a new topic on a list of subjects to be addressed for this iteration of the Guidelines. Also, Heather Leidy, a protein specialist from Purdue University, is likely the first committee member to bring the perspective that increased protein consumption might be an effective strategy for fighting obesity.

These new viewpoints are likely to face a challenge from an old guard who have served on the Guidelines’ committees before and could therefore be expected to have an instinct to defend the status quo. This includes Dr. Schneeman, two times a member of the Guidelines committee, in 1990 and 1995, and Northwestern Medical’s Linda Van Horn, who served as chair of the 2010 Dietary Guidelines committee. At the time, she told the Washington Post,

What has been done till now isn’t working. To do nothing more effective than we have means that five years from now we’ll be in an even worse situation. And that would be unconscionable.

Since those 2010 Guidelines that Van Horn oversaw, rates of diabetes and obesity have in fact continued their relentless climb upwards. We hope this gives pause to all members of the 2020 committee. This new committee has an opportunity to embrace new ideas that might have a chance at reversing these diseases. We sincerely hope they seize this challenge, learn from past mistakes, and with an open mind, embrace new ideas for the future.

Tucker D. Goodrich contributed extensive research for this article.


Footnote:
[1]
Jamy Ard: Professor, Epidemiology and Prevention, Wake Forest University

Regan Bailey: M.P.H, Public Health and Epidemiology, Johns Hopkins University

Lydia Bazzano: PhD, Epidemiology, Tulane University

Carol Boushey: PhD; Nutritional Sciences and Epidemiology, University of Washington 

Elizabeth Mayer-Davis: PhD, Epidemiology, University of California, Berkeley

Timothy Naimi: physician and alcohol epidemiologist at Boston Medical Center

Rachel Novotny: “Research Interests: Nutritional epidemiology,” University of Hawaii at Mānoa

Joan Sabaté: Professor of Nutrition and Epidemiology, Loma Linda University School of Public Health

Linda Snetselaar: Department: Epidemiology, University of Iowa

Jamie Stang: Associate Professor, Division of Epidemiology and Community Health, University of Minnesota

Linda Van Horn: “focus of work...cardiovascular epidemiology” Northwestern Medical https://www.feinberg.northwestern.edu/faculty-profiles/az/profile.html?xid=13194

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tuck
991 days ago
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It will be interesting to see how they do...
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There's New Research on the Science of Barefoot Running

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It was Daniel Lieberman, the barefoot-running evolutionary biologist from Harvard, who first got me thinking about impact forces. Back in 2010, he and his colleagues published a hugely influential study in Nature that compared the “collision forces” of feet hitting ground for runners with and without shoes while landing on their heel or forefoot. The stark differences in the paper’s force curves provided crucial scientific ballast for the minimalist running movement—but a new study suggests we may have been interpreting those curves all wrong.

The new study, which appears in the Journal of Applied Physiology, comes from Peter Weyand’s biomechanics group at Southern Methodist University, led by his former doctoral student Andrew Udofa, along with Ken Clark (who is now at West Chester University) and physicist Laurence Ryan. By rethinking what running force curves tell us, they’re able to resolve a longstanding mystery about the role of shoe cushioning and potentially offer an accessible and individualized way of testing which shoes are best for you. To understand why, we first need to look back at Lieberman’s curves.

If you ask someone to run on a fancy force-measuring treadmill (which costs several hundred thousand dollars) or force plate installed in the ground, you can get a characteristic curve that shows you how much force the runner is applying vertically to the ground with each step (and conversely, as Isaac Newton figured out, how much force the ground is sending into your body). Here, from Lieberman’s 2010 paper, is a typical example for someone running barefoot and landing on their heel:

barefoot running
(Courtesy Nature)

The key feature to notice is the little spike on the left side of the curve. That’s your heel slamming into the ground, a split second before the full force of the rest of your body presses into the ground. The dominant view among biomechanists is that it’s not the overall size of the force (which tops out at about 2.4 body weights here) that determines how likely you are to get injured; instead, it’s how quickly the force is applied, otherwise known as the loading rate. Thanks to the mini-spike of the heel strike, the force in this picture climbs very steeply, which is presumably bad.

Now compare how the force looks when you land instead on your forefoot:
 

barefoot running
(Courtesy Nature)

The little spike is gone! That means the loading rate is lower, and you’re less likely to get injured. At least, that’s the theory.

In truth, according to the new study, the little spike is still there; it’s just obscured by the bigger one. Back in 2014, Weyand, Clark, and Ryan proposed what they called a “two-mass model” to explain how these sorts of force curves vary under different conditions. In this model, the force curve always consists of two distinct components: a small spike that corresponds to your foot and lower leg smacking into the ground and almost immediately jarring to a halt; and a bigger, slower spike that corresponds to the rest of your body reaching the lowest point of its up-and-down motion. The overall force is simply the sum of those two spikes.

Here’s what looks like:

barefoot running
(Courtesy Journal of Experimental)

The curve shown here looks a lot like Lieberman’s heel-strike curve. But in a 2017 study, the SMU group showed that you get a very similar double peak when you look at world-class sprinters—even though they land on their forefoot. That was an important clue that the mini-spike isn’t a function of which part of the foot touches the ground first. Instead, it’s a function of how quickly you’re applying force to the ground, which depends not just on footstrike but also on speed, shoe characteristics, and other factors.

In the new study, the SMU team compared the force data from eight volunteers in four different shoe conditions: barefoot, minimalist (Vibram FiveFinger KSO), thin-soled racing flat (Nike Zoom Waffle Racer VII), and thick-soled running shoe (Asics Gel Cumulus-14). They wanted to explore a longstanding mystery called the “impact force anomaly,” which is that putting more cushioning in shoes doesn’t seem to reduce the loading rate that runners experience—a seemingly counterintuitive result.

Here’s what their data looks like, showing both the mini-spike associated with the lower leg (J1) as well as the overall force that’s the sum of both spikes, for two speeds (~6:40 per mile and ~3:50 per mile). The vertical axis, as before, is force in body weights, and the horizontal axis is time in seconds.

barefoot running
(Courtesy Journal of Applied Phys)

The first thing to notice is that for each speed the rising slope of the overall force curve—the loading rate—is pretty much the same in all conditions. But the lower leg component (J1) does change: the more cushioning they have, the steeper and higher that peak is. So what’s going on?

What the new results suggest is that we’re wired to automatically adjust our biomechanics to keep the overall loading rate roughly the same. In this study, the runners adjusted the angle of their foot strike to control how long that J1 impact took. When barefoot, they landed on their forefoot, which prolongs and softens the landing, with the calf muscles and Achilles acting as a shock absorber. In the thick-soled trainer, the presence of cushioning allowed them to slam down directly on their heel, which led to a sharper J1 curve without changing the overall loading rate.

What’s key here is the timing of that impact peak. If the initial peak is delayed long enough, it effectively disappears into the main peak, as in Lieberman’s 2010 data. But by delaying that peak, it ends up occurring at a point where the other, slower component of force from the rest of the body is much bigger. In other words, you reduce one of the forces but increase the other, and end up with a similar total force.

I realize we’re getting into the biomechanical weeds here, so let’s zoom out to consider what this means. The biggest practical insight: in the new SMU data set, changing your shoes, on its own, doesn’t significantly change your loading rate. Either your shoe cushioning softens the impact, or you adjust your landing to get cushioning from your calf and Achilles. Take your pick, because the end result—at least under these particular conditions—is the same.

That doesn’t mean this system is foolproof. If you head out for a barefoot run and land on your heels—either because that’s what you’re used to from a lifetime of running in shoes, or because, as in the Lieberman experiment, the guy in the lab told you to—then you’re going to generate really high loading rates, because neither protective mechanism (shoe cushioning or forefoot strike) is switched on.

Conversely, if you suddenly switch to a forefoot strike after a lifetime of heel striking, you’ll be putting a lot of unfamiliar stress on your calves as they take on the role of shock absorber. “There likely are injury implications,” Weyand says, “and these do line up with the eager barefoot adapters getting Achilles injuries.”

Weyand is justifiably hesitant to generalize, though. This is a small study of a few volunteers running under very specific conditions at fast speeds. It doesn’t give us the final answers about what shoes or running styles are best for everyone, or exactly how these forces translate into injury risk—but he believes it does give us a better way to answer those questions.

Crucially, the simplicity of the two-mass model means that you no longer need a prohibitively expensive force-measuring treadmill to assess impact forces and loading rates. Instead, all you need to know is how fast your lower leg is moving when it hits the ground; how long your foot stays on the ground; and how long each step takes. You can get those parameters with a high-speed video camera, or these days you could do it with a small leg-mounted accelerometer. Plug them into the two-mass model equation, and it spits out the force curve. So with some fairly simple wearable tech, you should be able to head to a shoe store, try on five pairs of shoes, and know in real time what impact forces and loading rates you generate with each one.

For distance runners, the goal would presumably be to minimize impact forces. But it’s worth noting that the opposite is true for sprinting. The primary way people run faster is by striking the ground harder: the more force you can plow into the ground, the faster you’ll go. “In this regard,” Weyand points out, “minimizing impact and loading rate is directly in conflict with increasing speed.” That’s one reason training shoes and racing shoes are so different—and it’s something else you can test for with this model, trying different shoes and form tweaks to see what maximizes your force output.

If there’s one thing we’ve learned in the decade since Lieberman’s initial results, it’s that we should be cautious about looking at force curves in the lab and assuming we understand how they translate into real-world outcomes like injuries and race times. That applies to the new SMU data too. But the model has the potential to solve two very current problems: taking biomechanics out of the rarefied lab environment and into the real world; and extracting useful insights from the firehose of personalized data generated by emerging wearable tech. Hopefully there will soon be an app for that.


My new book, Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance, with a foreword by Malcolm Gladwell, is now available. For more, join me on Twitter and Facebook, and sign up for the Sweat Science email newsletter.

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tuck
1004 days ago
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Interesting, although it still basically confirms that your feet work quite differently in a cushioned shoe...
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Review: Sockwa X8

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Review: Sockwa X8

Sockwa is known for their ultra-minimalist approach to barefoot shoes. Sockwa, not surprisingly, takes a "sock-like" approach to their designs—their shoes take a sock-like design and add a simple, thin, flexible sole for durability.

Sockwa sent over a pair of the Sockwa X8 to review. How'd they turn out? Read on!

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tuck
1046 days ago
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They look nice!
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NIH Seeks Feedback on Nutrition Research Plan

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As the leading government funder of nutrition research, the National Institutes of Health (NIH) is seeking public comment on a draft strategy to “coordinate and accelerate” clinical research over the next 10 years. This is a perfect occasion to contribute your thoughts and help guide NIH research towards important, unresolved issues in nutrition science.

This plan focuses specifically on clinical trials. While dietary policy to date has largely been based on epidemiological/observational studies, this kind of science can only serve, on the whole, to generate hypotheses. To test these hypotheses and provide more definitive proof, clinical trials are essential.

Thus, your contributions to this public comment period, which ends December 15, is an important opportunity to help direct the questions that might be tested in those trials.

The NIH Nutrition Research Task Force (NRTF) has prepared a draft plan that doesn’t prescribe specific research subjects, but lists seven broad research themes:

  1. Investigate nutritional biochemistry, physiology, and the microbiome

  2. Assess the role of nutrition and dietary patterns in development, health, and disease across life stages

  3. Explore individual variability in response to diet interventions to inform nutrition science, improve health, and prevent disease 

  4. Enhance clinical nutrition research to improve health outcomes in patients

  5. Advance implementation science to increase the use of effective nutrition interventions

  6. Develop and refine research methods and tools

  7. Support training to build an outstanding nutrition research workforce

These themes take a broad-brush approach. One clear oversight we have observed is that the plan calls for studying the health impact of nutrition and dietary patterns but only lists the Western, Mediterranean and vegetarian diets as examples worthy of research. The low-carbohydrate diet, which has proven in rigorous research to be one of the most promising options for reversing diseases, is not listed. This may be due to the government’s long-standing bias against higher fat diets. Yet just as the USDA-HHS have included “low-carbohydrate” as one of the diets to be studied for the next U.S. Dietary Guidelines for Americans, we would suggest that the NIH be similarly open-minded to this emerging and promising science.

If you choose to comment, we suggest noting this omission.

We also believe it is important for new research to provide clarity on other questions that challenge longstanding yet disputed advice. For instance, the majority of studies on salt have contradicted dietary recommendations calling for lower salt intake. Similarly, although calls to reduce red meat consumption are up, human trial data on meat thus far show no ill effects. Since these subjects remain contentious, more rigorous research is clearly needed.

Please offer comments to encourage clinical trial research on controversial topics that need further research.

Remember: your comments have made a difference in the past. They helped persuade USDA-HHS to put “low-carb” and “saturated fats” on the list of topics to be studied for the next Dietary Guidelines. Now is an opportunity to do the same with the NIH.

Responses must be submitted by midnight December 15. Here is the email for submissions: nutritionresearch@niddk.nih.gov.



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tuck
1092 days ago
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They'd apparently stopped funding nutrition research, so this is a major development.
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