In case you missed it, Lindsay Beyerstein has an interesting post on diets.
If diets don’t work, why do people keep using them? We often hear that people want “quick fixes” instead of lifestyle transformations. That doesn’t really explain the popularity of diets. Most diets make the dieter feel miserable. In fact, I’ve been driven to writing this post because of the incessant chatter of my dieting cube mates. They can scarcely talk about anything else. They can’t think straight. They are irritable. They are spending huge amounts of money on books and prepackaged meals. Most of them aren’t even losing weight.
My coworkers don’t really “need” to lose that much weight, even by their own standards. In theory, if they could just end every day 70 calories in the red, they’d all be at their goal weights by bikini/Speedo season. So, why aren’t these people more attracted to slower, more gradual weight-loss regimens?
I submit the answer is epistemological rather than physiological. People go on diets because don’t have reliable, detailed information about their own energy balance on a day-to-day basis. We’ve all read that an extra apple per day could translate into a 10-pound weight gain in a year. By the same token, switching from sugar to sweetener in your coffee would be expected to produce a 10-lb weight loss in the same period.