Obesity, Demystified

06/30/2010 05:12 am ET | Updated Nov 17, 2011

I believe most people understand that epidemic obesity is overwhelmingly accounted for by too many calories in, too few calories out. But in many quarters, there is surprising resistance to that notion.

There is resistance among my academic colleagues who seek 'the obesity gene.' To me, that seems a bit like looking for the 'fish out of water' gene to explain the breathing difficulties of...a fish out of water. Every gene that makes a fish a fish is guilty of the charge.

Similarly, a lot of the genes that make us Homo sapiens -- who survived through all the ages when calories were scarce and hard to get and physical activity was unavoidable -- explain why we succumb en masse to obesity in a modern world where physical activity is scarce and hard to get, and calories unavoidable. My prediction is that when the inventory is done, the genes that make us get fat under conditions of modern living will prove to look a lot like the genes that make us human.

There is resistance, as well, among the conspiracy theorists who think some nefarious intent must be behind it all. And there is resistance among the environmentally devout, who are convinced this is all due to industrial chemicals, hormones, and antibiotics. In fact, following a recent talk at Lincoln Center to some 1200 aspiring nutrition professionals, one asked me why I had left the issue of environmental pollutants out of my presentation.

My view has long been, and remains: once we account for that portion of the obesity epidemic that is readily explained by too many calories in, too few out -- if there is any left to explain (and I don't think there will be much!) -- then I will be interested in exotic theories, from hormones, to industrial chemicals, to the microbiota of our GI tracts, to adenovirus S36.

And while I was confident in this stance all along, I am one increment more so following a recent report in the New York Times regarding the rapid progression of obesity and diabetes in Qatar. The whole case is beautifully summed up in one paragraph:

"Like other oil-rich nations, Qatar has leaped across decades of development in a short time, leaving behind the physically demanding life of the desert for air-conditioned comfort, servants and fast food."

Period, end of story.

It matters that there is no great mystery behind epidemic obesity, whether its victims live by purple mountains' majesty, upon the fruited plane, or on the sands of Qatar. It matters that the mystery of epidemic obesity is explained, everywhere, in just the same way. It matters, because even the tough can't get going so long as they remain lost and befuddled.

We can't begin to fix what we don't understand. Fortunately, we understand the causes -- and thus the cures -- for global obesity, and the chronic disease attendant upon it.

The forces conspiring to impose the global health threat of obesity upon us will be difficult to change but they are unmysterious. Conditions of modern living account for, and demystify, obesity. The explanations are...everywhere. So, too, are the opportunities to do something about it!