Why We Crave
We all crave certain foods—chocolate tops the list—but since appetite depends a lot on context, it can be retrained.
By August 19, 2003 - last reviewed on June 9, 2016published
We've all been there. Cravings are a fact of life: up to 97 percent of Americans get seized by strong and specific urges to indulge. And for women in the U.S., chocolate tops the list.
It seems like there's nothing to do but either fight off the cravings or give in to them. Mostly, we give in, figuring it's hopeless—a simple biological fact of life.
But research from the University College of London shows that the yen for chocolate and other tasty treats may be an acquired habit. In humans, hunger and eating are strongly influenced by context. That seems to be true of cravings, too. Even though the desire feels deep-down and basic, habit and conditioning seem to have a lot to do with it. The wonderful implication: cravings for rich, fatty foods might be conquerable. You don't have to be a slave to your appetite; you'll like yourself better in the morning.
Psychologist Leigh Gibson, a professor at the university's Health Behavior Unit who studies appetite and food choice, rounded up several dozen student volunteers to find out whether people could be "trained" out of their cravings. The students in the study ate half a bar of milk chocolate twice a day for two weeks. Half ate their chocolate ration 15 minutes after finishing a meal; the other half waited at least two hours after a meal before having the sweet. The students filled out a diary rating the strength of their cravings and of the appeal of the chocolate bar by answering questions like: "If any amount of chocolate was available, how much would you want to eat right now?" Volunteers included both people who loved chocolate and those who could care less.
After two weeks, the volunteers who had been eating the chocolate on an empty stomach reported that their yen for chocolate was stronger. By contrast, the students who had been eating the chocolate on a full stomach said their cravings were much weaker. That was true for both cravers and non-cravers.
What's more, people who'd been eating the chocolate when full actually said that it now seemed a bit less pleasant to the taste. It seems that by eating the sweet when they weren't hungry, the volunteers had trained themselves to like it less.
"I do believe that one should be able to retrain one's appetite, or reduce one's craving, for particular foods by eating them only when not hungry," says Gibson. "However, this may only apply to foods that are relatively energy rich." He tried a similar experiment with dried fruit bars and got very different results, suggesting that lower-calorie foods may not have the same effects.
But Gibson points out that most commonly craved foods—ice cream, pizza, cake—are also very rich and energy-dense. "It's a lot easier to walk past the green grocers or fruit stall without being tempted to buy than to walk past the confectionery counter or cake shop, isn't it?"
The bottom line, he says, is that it's a good idea not to eat foods you are trying to avoid or eat less of when you are very hungry. "The trick is to eat frequently enough to avoid strong hunger, but without eating too many calories in total." Easier said than done, he admits—but his finding may explain why people who "graze," or eat small amounts throughout the day, may often be healthier and slimmer.