Tuesday, September 06, 2011

Will there ever be a grand unified theory of obesity?

In the nutrition blogosphere there's a bit of a debate going on right now. It started during a recent conference on ancestral health when Why We Get Fat's Gary Taubes criticized the theories of researcher and blogger Stephan Guyenet, and while criticism is all fine and dandy, it was the manner in which Taubes addressed Guyenet that led Guyenet to launch his own critical analysis of Taubes' work.

In a nutshell, Gary Taubes is the champion of the carbohydrate hypothesis of obesity, and Stephan Guyenet, the food reward hypothesis.

So who's right?



Both and neither?

Does it matter?

While I'm not fond of the way Taubes tends to argue in terms of what appears to me to be his liberal use of logical fallacy, personal observation, straw men, and ad hominem, I do think highly processed carbohydrates are involved in societal weight gain.

I also think there's a great deal of merit to Guyenet's belief that the hyperpalatable foodstuff that makes up the bulk of our modern food environment short circuits the brain's normal ability to moderate intake (you can read Guyenet's series on food reward on his blog starting back in April of 2011).

As a clinician however, neither strike me as the one right solution. Most people simply aren't going to be willing to restrict carbohydrates to the point of a natural reduction in caloric intake, nor do I think people are going to be willing to live on bland diets forever.

That said, reducing carbohydrate intake (especially ultra-processed carbohydrates) and trying to minimize exposure to hyperpalatable foods, are in fact both recommendations I regularly provide my patients.

So why isn't there one right way to go?

Probably because people are complicated. Both psychologically and physiologically. Brains are pretty crazy places, and so are chromosomes in that there are literally 100s of genes involved in eating behaviours, metabolism, appetite, etc.

So does anyone truly believe obesity has only one cause and therefore only one solution?

In Guyenet's case, the answer's clearly "no" as he's said as much,

"The food reward/palatability hypothesis of obesity is not mine, it's a hypothesis that originated in the 1970s, perhaps earlier, and is a major subject of ongoing obesity research. I don't expect it to explain every instance of obesity."
In Taubes case, it would appear as if his answer's "yes". Carbs or bust. In fact his most recent blog post recounts how he believes that for decades, presumably unlike he himself, pretty much all researchers have been operating with, "suboptimal intelligence" and that their "wrong answers", "border on inexcusable".

It's quite the righteous stance given the very clear holes Guyenet (and others) are able to poke in Taubes' theories.

Of course I'm confident Taubes will find some real holes in Guyenet's theories as well - something he plans on doing on his blog over the course of the next little while.

That's because unlike physics, I don't think anyone (other than potentially Taubes) really believes that there's one grand unifying theory of obesity, so there will always be holes to find in every theory.

The Daily Lipid's Chris Masterjohn covered this "Dietary Dogmatism" well, and I just want to weigh in and comment that pigeon holes are small.

Carbs, food rewards, mindfulness, whatever - it doesn't really matter. Bottom line being that if you figure out what works for you, stick with it regardless of whose theories resonate with you intellectually, because unless their application helps you to find a means to manage your weight living a life you actually enjoy, you'll have to keep on looking.