Sunday, January 16, 2011

A magic calorie ride

Bob, an office supervisor in Toronto, considers himself an addict. But the substance he’s prone to abusing isn’t drugs or alcohol—it’s food. “I would gorge on Raisinets, pizza, anything that I could get in quantity,” says Bob, 60, who asked that his last name not be used. He ran up a $4,000 Visa bill, almost all of it on food. Eating as a stress release, “I averaged about 15,000 calories a day.” He weighed 336 lb. at his heaviest. “I’m no scientist, but I think it’s an addiction,” he says. “When I read about how a drug addict behaves, my response is the same to food.”

The term “food addiction” is controversial, but recent studies have shown that high-calorie foods engage the same regions of the brain as drugs like heroin and cocaine. Over time, scientists say, a high-fat diet can impair the brain’s pleasure centres like those drugs do, encouraging ever-larger binges and making it harder to quit. Remarkably, a mother’s diet might even hard-wire her baby for obesity later on in life. “It’s too early to call it food addiction,” says Teresa Reyes of the University of Pennsylvania School of Medicine, who studies how the brain adapts to changes in diet. “But there is absolutely increasing evidence showing that the brain responds to high-sucrose, high-fat diets in a very similar way that it responds to drugs of abuse.”


At the Society for Neuroscience’s annual conference in November, Reyes presented her latest work: mice that were fed a high-fat diet for a long period of time, she found, showed changes in parts of their brains associated with pleasure and reward. Just like cocaine or heroin, unhealthy foods seem to trigger the brain’s pleasure centres, eventually desensitizing them. It becomes a vicious cycle. “To reach the same level of reward, the person needs to eat more rewarding food,” Reyes says. “It’s very similar to what happens in chronic drug abuse.” (This data is now under review before publication.)...

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