How come this point wasn’t brought up during the study’s design (the Hall one).
Antonis Damianou

Antonis Damianou. My responses below in italics

  1. How come this point wasn’t brought up during the study’s design (the Hall one). It was, after all, funded by NuSI… If you look at the clinical trial registry, you’ll see Hall’s study labeled a “observational” and “pilot” in recognition of the highly limited and exploratory nature of the work. This was never meant to be definitive — unfortunately, that circumspection was lost in the publication.
  2. How long would you say it’s needed for the claimed body composition benefits to become apparent? In this post, I show evidence that the process of adapting to a high fat diet takes at least 2 to 3 weeks, and possibly a bit longer. Studies of less than this length have no relevance to our understanding of long-term effects.
  3. Isn’t it true that after around 3 weeks of being in ketosis, even the small metabolic advantage that comes from the metabolic cost of gluconeoenesis becomes insignificant, since the body switches to uzing ketones instead of glucose? I don’t think of the so-called “metabolic advantage” as relating to chemistry, but rather physiology. The thermodynamics of chemical reactions probably have a minor impact on energy balance. Of more interest is whether the body, due to better access to stored metabolic fuels, does not lower metabolic rate as precipitously with weight loss (an effect that exceed 400 kcal/day in our JAMA 2012 study).
  4. Can you share even one metabolic ward study that compares two isocaloric, protein matched diets (a ketogenic and a non-ketogenic one) which shows a benefit to the former? Actually, Hall’s pilot study. He found that energy expenditure by doubly-labeled was 151 kcal/day greater on the ketogenic diet, despite indisputable bias agasint that diet from ongoing weight loss and other factors. (Note that Leibel and others have argued double-labeled water is actually more appropriate for adaptive thermogenesis than whole room calorimetry, the other end point Hall studied.) Our JAMA 2012 study did have a 10% difference in protein, but the literature is clear, as I documented, that this difference in protein can’t explain a 325 kcal/day effect. In any event, the bottom line is clear: we don’t have any long-term feeding studies to assess the question. Thus, claims by Hall of “falsifying” the Carbohydrate-Insulin Model are unfounded.