Back in January, at a lecture by a social psychologist friend on the nature of commitments and cults, I found myself scribbling notes like mad as my mind drifted to our culture’s crazy allegiance to diets. Here’s what I learned about why, against all evidence and rationality, we insist on clinging to them.

I get intrigued when research is counter-intuitive and a few observations of my professor friend were nothing but. First, he pointed out that we don’t make commitments to goals which make sense and that we know are achievable. Instead, we make commitments to things we don’t know are true and possible but hope or wish were so. For example, custom aside, uncertainty is the reason we feel a need to “commit” to marriage: because we can’t know we’ll live happily ever after, we make a pledge to ensure that it will happen. The same goes for diets. We have no assurance that they’ll slim us down, so we hope that by believing with all our might that they will (against scientific evidence and our own experience and judgment), it shall come to pass.

Second, my friend noted that the more we sacrifice for a commitment and the harder it is to keep it, the more committed we become. Wow—I told you this stuff was counter-intuitive! The more ridiculous a diet is—fasting, grapefruit, only carbs, no carbs, etc.—the more we cling to the belief that it’s a winner. The more we have to deny ourselves, the harder we try to do so, and the firmer becomes our resolve to keep on truckin’. It’s true: hardship strengthens commitment. Apparently we believe that what comes naturally and easily and makes perfect sense is not worth pursuing, but give us chances of slim to none and sign us up. (Note the striking similarity to the way some folks seek approval and love from those who ignore or abuse them.) And, of course, the more we invest in commitments such as dieting, the more difficult it is to be honest and fess up that they’re not working. Instead, because we hate to think we were wrong all along and rue the lost time/energy/money we’ve expended, we redouble our efforts and soldier on.

Thanks to social psychology for helping us understand the pretzel logic to which we succumb around diets. In sum, “normal” eating, which comes naturally and automatically, becomes the wrong path, while diet hardship (deprivation, obsession, resentment, and rebellion) inspires commitment. How about using clear thinking? Because learning “normal” eating makes sense, put your efforts into doing it every day. No need to make a commitment. Rather, try simply valuing and enjoying how your mind/body feels when you eat intuitively. Then do the same thing again tomorrow.