Hall et al., THE FIRST SIX DAYS (update)

Some people say the study design was rigged to favor the Low Fat diet (LF), which is dirty business but not exactly criminal; sometimes, this happens in science.

The claims go something like this: baseline diet was so high in carbs that they were locked into making unreasonable adjustments to formulate isocaloric low fat and low carb diets; eg, fat was too low in the low fat diet and carbs weren’t low enough in the low carb diet.

The biggest finding was “Fat Imbalance,” which favored LF.  Here’s why I don’t think the baseline diet mattered very much.

Tl;dr: drastically cutting fat intake (LF diet) is much more effective than upregulating fat oxidation (LC diet) to create a large Fat Imbalance in an acute setting, ie, THE FIRST SIX DAYS.



Hall’s diets


Red flag alert: the 6 day cumulative fat imbalance was two times greater on the low fat diet.  We know that under highly controlled experimental conditions, these diets should yield roughly similar changes in weight over time.  That alone should put a red flag on the use of “Fat Imbalance” in this context.

I’m not sure why the numbers don’t match Hall’s exactly, but they’re close enough to make this point.  The change in fat oxidation on the RC diet (45 g/d) would have to be doubled (100% higher) to make the 6 day Fat Imbalance match that on the RF diet.  DOUBLED.



Low Carb enthusiast Ivor Cummins posted some alternative diet options HERE:


Ivor’s diets


Assuming similar changes in fat oxidation rates (or not), this is still far short of correcting the overall difference in Fat Balance.  However, a lower level of carbs may lead to a higher rate of fat oxidation, as seen in this paper by Patterson and Potteiger… but despite having diets similar to Ivor’s, it only led to a 20% higher rate of fat oxidation.  This is far short of the doubling that would be necessary for equal Fat Imbalances.  The difference between the two diets is slightly reduced, but still far short of equal.  Drastically cutting fat intake is a much better way to induce a big Fat Imbalance in an acute setting.

Acute: Patterson’s study was 2 days; Smith et al., 4; Hall’s was 6.
Fat oxidation simply takes more time to upregulate.



Diet-induced changes in energy expenditure


I do expect that in the context of Hall’s study (with either his original diets or even with Ivor’s), had they continued the study for a few more days (or possibly weeks), we’d see the difference in Fat Imbalance evaporate.



Fat oxidation will upregulate enough, EVENTUALLY, and I’m pretty sure Dr. Phinney actually showed this empirically.  The point is that I believe there were a few key variables which led to apparent LF superiority, none of which being baseline diet or foul play: eg, drastically cutting fat intake in the LF group to create a large Fat Imbalance and stopping the study at 6 days.

Don’t get me wrong, Nutrient Balance is probably more sensitive (and accurate) than DXA for detecting small changes in people on different diets under non-homeostatic conditions (eg, actively losing weight) (eg, Silver et al., 2010)… but may have been somewhat misleading in this context.

IOW, I don’t think a lower carb LC diet wouldn’t have changed much in this setting.

And no, this study still didn’t debunk Low Carb or insulin or whatever.







calories proper



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  • John Lushefski

    I don’t get how some people get so bothered or confused by something like this. First, as you say, it doesn’t debunk the “insulin hypothesis” or whatever. Second, it was six days; you could almost simply say, “Who cares?”

    Overall it is near impossible to design and conduct a study that will satisfy everyone. For example, there are tons of low carb vs low fat studies out there where foods are orange juice, toast, mayonnaise, etc. I don’t consume any of those.

    This also is certainly not the first study to find an “advantage” of carbs over fat. There are some overeating studies out there, but again, foods/variables are not satisfactory.

    People need to relax and “soak up” everything, as opposed to simply jumping on the latest published recommendation/result. There is so much useful information available, from human trials, to rodent studies, to theory; it is silly to get worked up from this. If the next headline shows two week low carb outperforming low fat, the universe will tear!

    • TechnoTriticale

      re: I don’t get how some people get so bothered or confused by something like this.

      Because my tax money funded this pile of poo, which looks to be part of a personal vendetta by a CICO zealot against Gary Taubes. This isn’t just the usual biased incompetent nutrition science. This is malicious propaganda disguised as science.

      “There may be some satisfaction in puncturing low-carb champions’ claims of metabolic superiority, Hall said.”, as reported in several news articles spinning this mess as
      “Low fat beats low carbs”.

      • John Lushefski

        That makes sense, but I was referring to low carb eaters who get worried by these headlines. Mark sisson said that he got 100s of emails about it for instance. It is stupid that someone should need a guru to say it is okay, that they don’t have to immediately switch to a very low fat diet.

        • TechnoTriticale

          re: Mark sisson said that he got 100s of emails about it …

          Tom Naughton guessed that it broke his record for “did you see this” emails. I suspect that every LC, VLC and keto blogger has felt the need to address it.

          I’m always willing to be mistaken, so when I see dissonant headlines, I make an effort to find and read the original paper (often not linked from the breathless news spin).

          The average eater either doesn’t make the deep dive, or doesn’t know how to tell a valid paper from one that belongs on bog roll in the loo. So they ask/check people they know who do know how to read nut. papers.

          Personally, I think the blogosphere has responded appropriately to this profligate waste of grant money and metabolic ward time.

        • This Old Housewife

          I think they were just looking to Mark to interpret the data to make it easier for the layperson to understand…like me, for example. I didn’t write him, but I do read him.

      • Nagar J

        “…looks to be part of a personal vendetta by a CICO zealot against Gary Taubes”

        Interesting that Hall conducted one of early studies funded by NuSI (Taubes and Attia). Will be interesting to see the study design and results.

        • TechnoTriticale

          re: Hall & NuSI

          More disturbing than interesting. Hall is clearly both motivated and qualified to sabotage any clinical trial that might reveal a truth inconsistent with his religion.

      • valerie

        The study was registered and started before Taubes’ statements (that ended up being quoted in the paper). Accusing the researchers of foul play, or nefarious intentions, or wasting taxpayers’ money are serious charges. I wouldn’t throw them around so carelessly.


        • “Accusing the researchers of foul play, or nefarious intentions, or
          wasting taxpayers’ money are serious charges. I wouldn’t throw them
          around so carelessly.”

          I agree.

      • This Old Housewife

        The low-fat contingent will die off someday–all we can do is wait for it to happen.

        • TechnoTriticale

          re: The low-fat contingent will die off someday …

          And following their own advice might play a role in that.

          In the meantime, the immediate result of this confounded trial is that the present policy nonsense of “move more, eat less” remains in place. Herds of hapless humans will continue to be fattened, sickened and prematurely killed by the official USDA MyPlateOfMetabolicSyndrome diet (and its clueless clones worldwide), and healthcare costs will continue, unsustainably, to rise faster than GDP.

          What this NIH trial actually learned, and how it’s being spun, have little in common. While we await the results of the NuSI trials (and hope they aren’t bungled or sabotaged), we’re left with people continuing to try random named diets, and often getting starting results when those diets are low carb. Mere anecdote, of course.

    • CynicalEng

      I think the “who cares” are people trying to achieve a shift in dietary advice and thinking away from lipophobia to carbohydrate restriction, particularly in diabetes. The title of Hall’s study, and the PR bandwagon that came with it, gives the conventional wisdom people something to throw back at you “the latest thinking is that low fat is more effective for body fat loss” even if the numbers don’t justify that.

      • jasmine johend

        Yes this, just when there seems to success with the “fat is not bad message” slowly filtering in to the general public, this comes along and drops a bomb. This study makes no difference to us of course, going LF would cause instant hunger/weight gain for me pfft that, but to the media, dietitians, family doctors, general public it may be enough for toes to be quickly withdrawn from tepid waters. Going one step forward and now two steps back, it’s a shame.

        • This Old Housewife

          And you wouldn’t BELIEVE the media attention this got! I couldn’t go ANYWERE online without seeing this monstrosity. I believe this was designed more as a PR piece than an actual meaningful study, and Bill’s analysis shows just that. Will the ANALYSIS ever make the press rounds that the study did? Nope. So the public will continue living in the Matrix world that politics created.

  • Jack Kruse

    when will people stop arguing over studies on food and start focusing in on light and circadian biology. They argue about things that do not matter and ignore those that do. Amazing.

    • So I can eat whatever in the right lighting 😉 ?

      I’m curious about light on the body – any good links on the subject?

    • FatInTheDark

      This is great! In absolute darkness I’m all ripped with 8-pack rock solid abs. Don’t turn the light on.

      Just kidding. I’m fat in the dark literally. Everybody has a remedy these days.

    • joe

      Yes, only “doctor kruse” has the real remedy, its the leptin, no its the breakfast, no it’s magnetism, ok the REAL secret is cold showers!
      It’s all somewhere in my 50,000 page blog and $50 webinars

  • CynicalEng

    The elephant in the room is glycogen depletion. Fat oxidation in RC didn’t increase in Hall’s study because it had no need to – glycogen reserves were being depleted providing supplementary fuel that wasn’t on the balance sheet. I extrapolated the data and it looks like this would drop to zero by about day 8.5 so *starting* the analysis at Day 10 of consuming the diets would have been a level playing field.

    • Fat oxidation DID increase — see Fig 2C & 2G and Table 3.

      I agree, starting at day 10 would have been an improvement.

      • CynicalEng

        For sure, I was trying to say it didn’t need to increase *further* because of the glycogen depletion. FatOx in some studies has been well over 1000 kcal/day so I don’t think it hit a ceiling.

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  • weilasmith

    putting this comment here even though it is off topic. a very small, short study found that type 2’s who skipped breakfast had blood sugar spikes at lunch and dinner. this study, even though it targets type 2’s, might be additional evidence for the importance of circadian rhythms and blood sugar regulation.


    i have been prediabetic in the past and my bg will spike with a bowl of oatmeal. this study is important to me because i often skip breakfast and i don’t test my bg all the time since it is not crucial as a non-diabetic. i can test this out on myself very easily.

    • Hi Weila, thanks. I’ve blogged about Jakubowicz’s work in the past. http://caloriesproper.com/?s=Jakubowicz+

      Interesting stuff.

      • weilasmith

        i posted this on a diabetes forum and am posting it here in case anyone has something to add. especially since i can only understand a little bit of the abstract:

        i’m pretty sure that the type 2’s were not on insulin as at the end of the article it said: “The researchers are planning to conduct a similar study on type-1 diabetics, who require daily insulin treatment.”

        i found the abstract, but my limited science background means i only understood the part about insulin peaking earlier for lunch and dinner if breakfast was eaten. if breakfast was skipped, insulin peaked later leaving the individual with high bg’s for a longer period of time. i am interested in the idea that our pancreas may predict how much insulin we need before we eat, based on previous recent meals, not necessarily based on what we are eating at the moment. i first heard about this from art de vany. that’s why i was interested in a previous post about the effect of daytime bg fluctuations on night time bg fluctuations and the resulting quality of sleep … of which mine in poor :>( …here is the abstract. for those who understand more of it, please post if you see anything interesting.
        “Insulin peaked higher and earlier at 30 min after Lunch in the Yes Breakfast group vs at 60 min after Lunch in the No Breakfast group…”

        intermittent fasting (like not eating breakfast) might work for people who regulate glucose well either because they are not diabetic or they know how to mimic a working pancreas at least fairly well using exogenous insulin.

        • weilasmith

          i did my little 20 gram protein breakfast vs coffee splenda breakfast and i had NO huge spike in blood sugar. i might have had an insulin spike cuz i got a lower bg value of 86 (low for me as a post prandial value) that went up to 103 15 min later. BUT the main thing was skipping breakfast left me restless and distracted, which isn’t a good feeling if you are already tired and have trouble concentrating to begin with. so breakfast will NOT be my intermittent fasting time. i may try dinner/light dinner if i have equal or better sleep. if my sleep deteriorates further-no intermittent fasting at all for moi/wo.

    • daz

      hi weilasmith,

      what are you using for your ~20 grams of protein.

      (i’m looking for breakfast protein options)

      • weilasmith

        hi daz. i will eat just about anything. so if i am not that hungry, and i usually am not for breakfast, i will eat rotisserie chicken or tuna mixed with ranch dressing. it is a low volume of food. if i am hungry, i can scramble or hard boil eggs. eggs have 7 grams of protein each. 2 eggs scrambled is 14 grams + 1 oz on cheese shredded on top are cooked in the scramble is 21 grams. i also like turkey sausages which you just have to microwave. i have also eaten kipper snacks with sour cream on top for breakfast. sour cream is a comfort food passed down to me from my russian babushka.

        • daz

          thanks weila…

          & i will take a look at your blog

        • daz

          just quickly opened your blog up weila,
          have not had a chance to read yet, but will.

          i expect you know this already, the formatting is a bit hard on the eyes.

          i’ll prob paste in to MS Word so i can digest it more easily

          • weilasmith

            “i expect you know this already, the formatting is a bit hard on the eyes.” i am too lazy to research how to make it look nice. i really just have it for me to remember the little experiments i try. if i were more organized i could write in a notebook, but i would lose it eventually…:( this time i am telling people about the blog because i actually have something that would for the most part be valuable for women who can’t sleep because of temp changes from perimenopause. i can’t do hrt since my mom died from estrogen receptor positive breast cancer. so if my daughters grow up to have my problem, i will have something to help them, and maybe help strangers too.

      • weilasmith

        “hi weilasmith,

        what are you using for your ~20 grams of protein.”

        I use a food scale to weigh out portions of rotisserie chicken or use prepackaged tuna/kipper snacks, all of which are at least 20 grams. 1 egg is 7 grams of protein, and 1 oz of cheese is 6 or 7 grams. i might have more than 20 grams of protein for breakfast, but that is a minimum. i am blogging about how i have gotten 5 days of better sleep so far using bill’s circadian hacks at paleoexperiments.blogspot.com
        i don’t eat tuna everyday because of mercury concerns. maybe 3 times a week at most.

  • weilasmith

    does circadian mismatch cause

  • weilasmith

    does circadian mismatch cause elevated central sympathetic activation? if so, how is that measured?

  • weilasmith

    bill, your suggestions have enabled me to sleep without temperature changes of hot to cold waking me up all night. thank you. would you be interested or have you done a post of the alarm clocks that wake you up with different levels of light? how about rating gadgets that monitor sleep quality? these type of gadgets are just icing on the cake, but i’m still interested in them. my daughter who has adhd has trouble falling asleep like a lot of people with that condition, so those gadgets might catch her interest more than me telling her to copy what i do (she is 17). so a sleep gadgets post, PLZzzzzzzzzzzzzzzzzzzzz

  • weilasmith

    “The findings show that age-related reproductive defects can be reversed by manipulating light-dark cycles, suggesting that changes in light exposure have the potential to also affect fertility in aging women with disrupted circadian rhythms.

    –Charlotte Schubert”

    I’m trying to manipulate my light exposure to affect my disrupted circadian rhythms in perimenopause! Couldn’t they get some aging female mice and measure if hot flashes decrease with greater entrainment to circadian rhythms?????????????????????

    • I can’t think of any contexts where “greater entrainment to circadian rhythms” isn’t beneficial!

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