Sometimes just the thought of your favourite food is enough to make your mouth water.
But if you go through the mental exercise of imagining eating the whole thing - every bite, chew and swallow - it can actually dampen your appetite for that particular food, according to a study being published today in the journal Science.
The surprising results seems to fly in the face of the long-held belief that thinking about something desirable makes you crave - and consume - it even more.
"Our findings are pretty counterintuitive," acknowledged lead researcher, Carey Morewedge, a psychologist at Carnegie Mellon University in Pittsburgh.
The researchers performed a series of experiments in which some of the participants were asked to imagine eating lots of a specific food, such as M&Ms. Some of the other participants were asked to imagine consuming just a few of these treats. And still another group was told to think about a completely unrelated job, such as inserting coins into a parking meter.
After they had performed their mental tasks, the researchers placed a bowl of M&Ms in front of the participants and let them eat at will.
The participants who had imagined eating lots of M&Ms ate significantly fewer than the participants from the other two groups.
So, why did those who imagined eating the most candies end up consuming the least? Dr. Morewedge believes it's related to a process known as habituation. In the case of a desired food, the first bite is the best. As you eat, your craving steady declines until you've had your fill.
While scientists have known the habitation process takes place when you consume a real meal, they never realized it could happen with an imaginary one.
"These results tell us that habituation can occur in the absence of exposure to the stimulus itself - and just purely as a result of the mental presentation of the stimulus," said Dr. Morewedge.
He believes his study could lead to new ways of helping dieters stay on track. And he's convinced the traditional approach of "trying to suppress one's thoughts of desired foods in order to curb cravings for those foods is a fundamentally flawed strategy."
Of course, that remains to be seen. A lot more research is needed to prove dieters can be satiated with figments of their imagination.