"Habituation is a decreased physical and behavioral response to food," says Morewedge. "For instance, the tenth bite of pancakes is less desired than the first bite. People habituate to everything from the brightness of light in their room to the taste of their pancakes."
So by tricking the brain into experiencing what it's like to consume a particular food, the body starts to become habituated to the taste and enjoyment of eating it. By the time the real food comes around, the brain has already gotten sick of eating it earlier, so you eat less.
"It's sort of 'eating vicariously' via their imaginations," says Dr. Keith Ayoob, associate professor at the Albert Einstein College of Medicine. This might help dieters stop stressing out over avoiding certain foods, Ayoob notes, because, "in a way, it allows them permission to imagine eating whatever they want. They stop playing tug-of-war with a particular food. Then when they finally get the food, they've already had a 'head start' on the experience so they may feel less need to overconsume it."
It's too early to tell if playing pretend with those hard-to-resist holiday treats could actually keep off those extra pounds, Morewedge says.
The effect only works on the specific food item imagined, so trying to dampen a craving for pumpkin pie would still leave you susceptible to sugar cookies, for instance. Also, as soon as another food is imagined, the habituation to the first food is wiped out.
"It's just not viable to imagine every kind of food at a holiday dinner, and as soon as you imagine the second one, it will wipe out the first," Morewedge says. Researchers also don't know how long the effects last.
But Morewedge suggests this kind of habituation could have implications for other types of cravings, such as those for cigarettes, drugs, and alcohol.
This might be a slippery slope, however, says Bergen-Cico. "The sight, smell and sounds associated with prior alcohol and other drug use cause very powerful cravings for addicts. Effective recovery includes learning to extinguish and ride out cravings," she says. "I think this would be an effective tool for food, but a dangerous approach for people with alcohol and other drug addictions."