Regina Willshire has a good post about Willpower and weight loss maintenance. Excerpt:

The rising incidence of obesity in the United States is not new - for decades now we've watched as each year more and more of our population is classified as overweight or obese; and it does not appear to be reversing, despite the continuous messages to eat less and move more, be aware of calories in and calories out, just do it and stick to it.

Oddly it seems, the louder the messages get, the fatter the population grows.

Yet, while it's acknowledged that in the long-term dieting doesn't seem to result in long-term weight stabilization and maintenance, few are asking why.

Instead we're left with the idea that all these tens of millions of people who lose weight on a diet lack the willpower and resolve to maintain a healthy-balanced diet in the long-term.

I've heard maintaining a calorie-restricted diet compared to holding one's breath. Some people can do it for longer than others, but eventually, we all give up.

I think Dave sums it up perfectly in the comments to that post:

I think people have trouble sticking to "diets" because they're forced into deciding between some disease that may occur in the future, or signals from their body that they're going to die NOW if they don't get some food. Widespread failure should be no surprise, and the whole "willpower" thing is idiotic. In any other context, having the willpower to cause your own death would be considered mental illness.

Maybe I'm just making excuses, but I don't think so. Being fat sucks and I've struggled more-or-less continuously to lose weight for the last ten years, while my weight has gone up and up, taking only short downward diversions before rebounding. Every time I try to cut calories, I start getting seriously hungry, which leads to either binging and gaining so fast it's scary or, if I'm lucky, going back to the slow but steady pace of weight increase that's been typical for me.

I'm desperately hoping that cutting the carbs will short-circuit my body's signals that I'm doing something terribly wrong every time I cut calories. The hypothesis is that my body's intense urgings for more food than I should be eating are the result of a reaction to carbohydrates and not something just innately screwed-up about me.

I'm going to give this low-carb thing a real try and see if it works.