Ever wondered why overweight people keep on gorging? It's because they get less pleasure from their food that forces them to eat more to be satisfied, scientists have claimed.
Researchers at the University of Texas study found that the reward pathways in the brains of overweight people become less responsive as they gain weight.
This causes them to eat more to get the same pleasure from their food, which in turn reduces the reward response still further, they said.
Lead researcher Eric Stice, a psychologist at the university, said the result suggested that overeating may push people onto a slippery slope akin to a drug addict's craving for ever-larger doses.
"People are having to eat more and more to chase the high," Stice was quoted as saying by the New Scientist.
Obese people are known to have fewer pleasure receptors in the brain than thin people to start, according to the researchers.