One of the "hot research" areas I've been following for the past few months concerns the melanocortin receptor (I'm a pharmacology geek, what can I say?) and the regulation of appetite, the cooperation with dopamine receptors for pleasure, and the nebulous (so far) link with the hormones that are thought to regulate appetite: ghrelin, leptin, CCK (cholecystekinin), NPY (neuropeptide Y), and so on. Briefly, researchers are finding that melanocortin receptors cooperate with dopamine receptors to produce the hedonistic pleasure brought on by food. Exactly how the cooperation occurs and the effects of it are more technical matter that I will not get into here.
The article in question is, unfortunately, a closed one, meaning that you either have to be at a university library or pony up $32 to view it, unless Google has archived it somewhere.
But the main point is that this essentially debunks the "genetic set point" that irritates the hell out of me. The set point refers to a range of weights in which your body will fall, given an endless amount of food and constant metabolism. For most people, alas, this set point is not at the waif-like weight of what is being sold as beauty, but substantially above it.
There is no question that one's weight is naturally predisposed to falling at/around a certain point, and that for everybody, this point is different. For a society trained to find pixie sticks beautiful, this point is much heavier than what they would like it to be.
Allow me to digress a moment to point out that the pervasiveness of the diet industry is unique to the United States, and I would venture to guess that its success is largely unique to the US. Undoubtedly there are diet companies in Europe, but aside from an occasional flyer advertising a gym, there are few ads for apple cider vinegar pills, dietic green tea drinks, or body wraps. There is no media pressure to conform to a slender physique, though there is plenty of social pressure--for starters, cars are expensive, fuel even more so, and the stores catering to expansive waistlines are few and far between.
Anyway: it should come as no surprise, then, that one's weight tends to be a function of one's daily habits. Eating, drinking, sleeping, and all that good stuff. The operative words are "daily habits"--patterns of learned behaviors and thought that circumscribe everyday operation.
Behavioral experts say that it takes 2-3 weeks of sustained effort to create a new habit, and if my nail-biting is an accurate indicator, and old habits can never be fully destroyed--they can be overridden, but never vanquished.
What does this have to do with the set point?
My problem with the idea of a genetic set point is that it assumes that your body is entirely independent of your brain. If you've got a lifetime of, say, comfort eating (guilty) behind you, it is going to take much more than six weeks of bikini-body-dieting to break you of the habit of responding to emotional triggers with food. And, most likely, you'll find that no matter how long it's been, you'll probably relapse occasionally (guilty, too). When you go about "remaking yourself", not only do you have to learn a new habit to override the old one, you have to learn a new way to activate the pleasure centers to get that sense of achievement. This is hard. Very hard.
That young children have remarkably plastic brains is no surprise. Kids can learn to speak perfect French or Chinese if they start early enough, while adults might be able to if they persist at it for a decade or two. But what we have yet to appreciate is the full spectrum of plasticity of the adult brain. We, too, can train ourselves to like broccoli and delight in string beans. We, too, can teach ourselves new habits. It is hard. It takes a damn long time, and not only does it take a long time, it often involves pushing ourselves out of our comfort limits.
But it's not like we don't have that choice.