http://www.vancouversun.com/health/c...724/story.html

One in 20 Canadians is a food addict, suggests new Canadian research believed to be the first attempt to measure the prevalence of “food addiction” in a general population.Researchers from Newfoundland’s Memorial University say that seven per cent of women in their study, and three per cent of males — five per cent of the population overall — met diagnostic criteria for food addiction, described by senior author Guang Sun as “compulsive overeating in harmful and unhealthy ways.”
The team used a measure known as the Yale Food Addiction Scale to assess symptoms of food addiction in 652 adults from Newfoundland and Labrador. The scale asks people how often they engage in certain eating habits, such as, “I eat to the point where I feel physically ill,” “I find myself constantly eating certain foods” and “I need to eat more and more to get the feeling I want.”
The concept of food addiction is highly controversial. Some see it as a way of “pathologizing” normal human behaviours and removing personal accountability from people. “It isn’t my fault I’m overweight. I have a food addiction.”
But the Memorial team says there is mounting evidence that some foods may activate the brain’s reward system in vulnerable people in ways similar to cocaine or alcohol.
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I don't know what the stats are in the U.S.A. and other places, but you can take a quiz here to see it this may apply to you: http://www.oa.org/newcomers/is-oa-for-you/