You've had a rotten day and all you can think about is curling up on the couch with [insert your favorite comfort food here]. What gives some foods the power to soothe? "Stress causes most people to want to eat, period," says David LaPorte, Ph.D., an associate professor at Indiana University of Pennsylvania who specializes in the psychology of eating disorders. "That's just built into our brains as mammals. If you put a paper clip on a rat's tail, the first thing it will want to do is eat. Also, food is extremely rewarding to the brain. Just the act of eating lights up the lateral hypothalamus like a Christmas tree."
When it's "excited," the hypothalamus — that cherry-size region of your brain that controls the sympathetic nervous system — releases the feel-good chemical dopamine. The dopamine makes your body want to keep eating to produce even more of the contented sensation.
Though comfort foods vary from culture to culture, they do tend to have one thing in common: carbohydrates. "Studies have shown that [consuming] carbohydrates decreases stress," says Judith Wurtman, Ph.D., author of Managing Your Mood Through Food (HarperCollins, 1998). Carbs, she says, stimulate the secretion of insulin into the bloodstream, which helps to clear all amino acids—except tryptophan—out of the blood. This leads to an increased uptake of tryptophan into the brain, where it is converted to serotonin, a neurotransmitter that can reduce pain, produce a sense of calm, and induce sleep. It's no wonder then that our bodies crave carb-rich foods like ice cream and brownies; not only do they taste good, but they may curb stress.
Chocolate is a heavy-hitter on the comfort food team, though the vote is still out on exactly what it is about the confection that makes it such a popular chill pill. "We are biologically evolved to like chocolate," explains LaPorte, "because mammals prefer foods that are sweet and higher in fat and calories."
Other researchers point to a substance contained in chocolate called phenylethylamine, which may stimulate the release of endorphins. In a study conducted at the University of Minnesota, however, subjects who claimed to experience chocolate cravings were given cocoa capsules, which delivered chocolate's chemical components but none of the sensory input. The result: The capsules did nothing to satisfy their cravings.
"Don't underestimate the emotional factor in the way certain foods make us feel good," says Linda Bobroff, Ph.D., a registered dietitian and nutrition educator at the University of Florida. "It appears that women tend to crave sweets and men tend to crave high-protein, high-fat foods like steak."
Note, too, that a less-is-more approach might be best when attempting to satisfy your cravings. Polishing off a pint of Rocky Road is not necessarily more comforting than having a cone, and could lead you to stress about your body in other ways.