Last week, I noticed that one of my clients was looking particularly slender. "For the first time, I gave up bread and all baked goods for Passover," she explained, "and now I'm down about three pounds! I never realized how much floury, sugary junk I'd been eating." And now that Passover has ended, I asked, what did she intend to do?

"I'm definitely going to limit my intake," she said. "Until I gave them up, I never would have thought I could go two weeks without breads, muffins, cookies and pizza. I used to think I'd never be able to turn down a cookie, but I learned that the less starchy stuff I eat, the less I crave it. I'm pretty sure that if I cut way down on the baked goods, I can get the other five pounds off almost effortlessly."

Interestingly, I've had Catholic clients who've given up "problem" foods for Lent and experienced similar results. They lose a few pounds, feel more aware of their eating habits and are in control of their food choices. When Easter comes and goes, they're still reaping the benefits of their sacrifice. They may have "given up" something for Lent, but they've received important gifts in return.

I've wondered why these faith or culturally motivated diet reforms work so well. From my observations, it seems as though "cheating" is far less common than on other diets and the positive changes seem to stick. One could argue, of course, that religion is the magic ingredient, but in some ways, I think that simply begs the question. Why does religious tradition succeed where diet plans fail?