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More reactions to the Hall Study

Published 7.22.2016
Reactions continue to the Kevin Hall authored, NuSi* funded study that falsified Gary Taubes' carb-insulin hypothesis. Here is a round up of reactions, plus Hall’s answer to the question why it wasn’t a crossover study. Basically, crossover would have introduced confounding order effects. This was a pilot study so it was small and the diets were extreme by design— basically giving the low carb diet the best chance possible to be the best. Then subsequent studies would back off the diet extremes and look for more nuance.

This is a brief announcement by Carson Chow (who has collaborated with Hall in the past) and the most interesting tidbit here is:

The experiment showed very little effect and refutes the carbohydrate-insulin model of weight gain. Kevin was so frustrated with dealing with Nusi that he opted out of any follow up study. Taubes did not support the conclusions of the paper and claimed that the diet used (which Nusi approved) wasn’t high enough in carbs.


And there is more to study:

There were some weird effects that warrant further study. One is that study participants seemed to burn 500 more Calories outside of a metabolic chamber compared to inside. This was why the participants lost weight on the lead-in stabilizing diet. These missing Calories far swamped any effect of macronutrient composition.



A reaction from someone who has read the paper (I still have not).

From the discussion:Therefore, our data do not support the carbohydrate–insulin model predictions of physiologically relevant increases in EE or greater body fat loss in response to a [low-carb] isocaloric KD.This next sentence should get your attention. It says, essentially, the fat you eat is the fat you wear:We suspect that the increased dietary fat resulted in elevated circulating postprandial triglyceride concentrations throughout the day, which may have stimulated adipose tissue fat uptake (44) and/or inhibited adipocyte lipolysis (45, 46).

(Note: bolding was in the post)
The men in the study (and they were only men) lost muscle mass while eating low carb. Both groups ate the same amount of protein to eliminate it as a confounder. And he (I think it’s a he) notes that NuSi’s website and social media have been dead for awhile. Methinks it’s not going well.

Here is MedPage Today’s take. Hall is a bit more equivocal in this interview with what the results show. And of course, Ludwig gets quoted as the requisite NuSi toady. This account gives the most detailed overview of the study and paper. Marion Nestle and Michael Eades are also quoted. Eades bet the farm on the Taubes’ hypothesis too.

So now the argument becomes whether low carb eating increases satiety— which is really a function of protein. But that’s not what the hypothesis was. The hypothesis was that if insulin levels were low, then fat couldn’t be stored. That didn’t happen.

*NuSi = Nutritional Science Initiative, Taubes' group set up to try and prove his hypothesis is true.
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