Ok, not really… but that’s what I thought when I heard the news reports of the latest weight loss study, that concluded – surprise!!! – cutting calories + counseling/support help people lose weight.  But I refrained from commenting until I could read the study itself in the New England Journal of Medicine, since I figured the news reports might have missed something.

Apparently not – or at least nothing major…

Of course, I’m not sure how the researchers were able to come to the conclusion that the macronutrient composition of the diet didn’t count.  From the way it’s described in the paper, the actual diet bookkeeping was pretty messy…

Despite the intensive behavioral counseling in our study, participants had difficulty achieving the goals for macronutrient intake of their assigned group. The mean differences among the groups in fat, carbohydrate, or protein intake at 6 months were nevertheless often greater than those in several previous trials comparing diets for weight loss. Substantially diminished adherence after the first few months is typical in weight-loss trials and occurred between 6 months and 2 years in our trial…Overall, these findings with respect to adherence to macronutrient goals suggest that participants in weight-loss programs revert to their customary macronutrient intakes over time but may nonetheless be able to maintain weight loss.

In other words, people may have cut their cals and exercised more, but – over time - it looks like they simply started doing their own thing(s). 

Another issue, is that only weight loss was measured, not body composition.  Body comp tests are often done in other studies, as it’s well-known that lean body mass – the stuff you WANT to hang on to - is frequently lost during weight loss diets.  But this is a topic the researchers completely ignored.  In keeping with this emphasis (or lack thereof), not one of the 40 references cited was to research conducted by Donald Layman, who’s done extensive work on the role of dietary protein and leucine for weight loss, and whose work demonstrates that high leucine diets improve body composition (i.e., greater fat lost AND lean mass retained) vs. higher carb, lower fat/protein diets.  In the end, it’s fat loss – not weight loss – that’s important, and this is where the macronutrient composition of the diet could conceivably matter.  So, in my opinion, the researchers really missed the boat on this.

So overall, no new ground was broken, and – really – the only good thing to come out of it was that many of the participants lost some weight, and kept most of it off over the two years the study lasted.  Thus, there was some value for the subjects, at least, if not for anyone else.

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