The studies, published in the October issue of Behavioral Neuroscience, help explain why dieters rebound and even one cookie can trigger a binge if someone's predisposed to binge.
Researchers at the University of Bordeaux 2 in France found that rats ran faster to chocolate breakfast cereal than to regular lab chow, regardless if they had been food deprived or had recently eaten.
When presented with the chocolate cereal, the food-sated group ate almost as much as the food-deprived group. But when presented with lab chow, they ate very little.
Researchers at the University of Alabama at Birmingham focused on the regulatory role of the brain's opioid system.
The study found that calorie restriction or stress alone were not enough to produce changes in food intake, but stressed and underfed rats ate twice the normal amount of Oreo cookies.
Researchers speculate that the deprived and stressed rats may have been essentially craving something good and rewarding.
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