MONDAY, Nov. 7, 2005 (HealthDay News) -- Observations of overstressed rats may help explain why dieters so often fail and binge-eat instead.
A combination of stress, deprivation and exposure to tempting food pushed the rats to overeat, according to two studies in the October issue of Behavioral Neuroscience.
One study by researchers at the University of Bordeaux 2, in France, tested three aspects of eating behavior in rats: motivation (how bad they want it); anticipation (how excited they were in advance); and intake (how much they ate). These three aspects of eating behavior were tested in relation to food type (ordinary lab chow or yummier chocolate cereal) and satiety/hunger.
The second study examined the link between binge eating and opioids -- neurological "feel good" chemicals that play key roles in food response in both the rat and human brains.
Rats binged on a particularly favorite food -- Oreo cookies -- when they were both overstressed and forced to diet. Either condition alone did not lead to binge-eating, according to researchers at the University of Alabama at Birmingham.
However, giving the rats an opioid-blocking drug reduced binge eating in the stress/dieting rats.
The findings may explain why some people on diets relapse into previous poor eating habits and why even one slip -- such as eating a single cookie -- can trigger 'pigging out' in people already predisposed to binge-eating.
The research could also help in the development of methods to help people avoid overeating, control their weight and improve their health.
The Nemours Foundation has more about binge eating.