Economics of Overeating (Why we do it)

An economic threory of overeating - feel free to tell me I'm crazy or make suggestions.

What is the cost of eating half the pan of that Sarah Lee slightly thawed chocolate cake last night? In actual weight gain, not much from this "one" indulgance, almost insignificant. But what is the benefit of this one indulgance? Need I answer that? It's chocolate cake, and for a half hour I'm in heaven. Benefits > Cost.

The above scenario highlights the application of the economic theory of Marginal Utility and generally explains overeating in my view. The theory goes that people will act in their self interest, and continue doing something (in this case, eating) until the marginal cost of doing it is higher than the marginal benefit of doing it. The term "marginal" is critical here, meaning it looks at a single act of consumption, in our case, one meal (or one cake). As stated in the above paragraph, the benefits of that one last indulgance was greater than its cost - when you look at it in isolation. So naturally you did it.

The theory goes that individuals (in general) look at cost-benefit one event at a time. So...we keep eating, makes perfect sense. For every piece of cake I eat, the weight/fitness cost of that one piece of cake was much lower than the benefit I derived from eating it. Conclusion - I eat it. Same theory holds for smoking as you might imagine - the cost of that last cigarette you had is practically zero, compared to the benefit of smoking it when you're addicted to nicotine.

So are we doomed? Is there a way to tip the balance of the cost/benefit equation? To do so we would need to either raise the cost of eating that one piece of cake, or lower the benefit. I haven't figured out any way to lower the benefit, but would propose a way to think about increasing the cost. One answer, I think, is a daily workout, and it needs to be a little taxing, its gotta hurt a little - not epic, but it needs to hurt a little. Here's why: if the workout hurts, physically taxing, expensive, inconvenient, etc., consider the piece of cake you ate that day as "wasting" that day's workout. You did it for nothing. That's a cost you are attaching to that day's indulgance.

So looking at it this way, you have changed the cost/benefit (the marginal utility) of that one piece of cake by increasing its cost. And maybe, just maybe, this changes your outlook.