…but it isn’t dead, imo, because that would be really hard to do. Like, seriously.
Wait, which “insulin hypothesis” was falsified? pic.twitter.com/31pOP9B6Ff
— Bill Lagakos (@CaloriesProper) May 11, 2016
side note: please consider the modern views of Taubes, Lustig, Gardner, Attia, and others on Carbs™. They’re less “Carbs-cause-obesity, keto-for-all, etc.,” and more thinking it might not be Carbs™ per se, but rather processed and refined foods. And #context… And I tend to agree at the moment (nuances and caveats are subject to change, as more evidence accumulates).
disclaimer: I haven’t seen the full text of Hall’s recent study, but that’s not really relevant to what I want to discuss. In other words, I don’t think the full text will provide any additional details on this particular point.
Tl;dr: this study was not designed to prove or disprove metabolic advantage or the insulin-obesity hypothesis.
It’s in the study design: four weeks of low fat followed by four weeks of low carb. We KNOW that weight loss slows over time (especially if calories are controlled, as they were in this study). It has to do with the order of treatments.
Weight loss-slowing over time in the Minnesota Experiment:
Now, what did Hall et al. do? Low fat diet first: rapid weight loss. ANY diet second: slower rate of weight loss…
however, by the last 2 weeks of low carb, fat loss looked JUST AS RAPID as it was during the low fat period*, even though it was handicapped by being the SECOND diet. *this bit might be clarified in the full text
again, I haven’t seen manuscript yet, but for now I’m just talking about the study design which shouldn’t differ much between the poster/talk and manuscript
My question: what would’ve happened if they had a group on low carb FIRST? They would’ve had the added benefit of simply being in the beginning phase of a weight loss diet. This study showed a low carb diet was just as good as low fat even when it is handicapped by being the SECOND diet studied. (Maybe.)
Alternate #2: they could’ve just kept a group on low fat for the last four weeks. I bet you’d see the metabolic slow down common of typical diets; the very same metabolic slow down that low carb gimped.
In other words, this study didn’t prove or disprove the insulin-obesity hypothesis, not because of the actual results (which we still don’t really know), but because it was not designed to do so.