For Michael Prager, food used to be much more than a way to get his daily doses of nutrients or to satisfy a craving for a tasty treat.
"From an early age, I ate for reasons that other people didn't, and I ate in amounts that other people didn't," Prager said. "I stole money from my mother's purse and I stole candy from stores before I was 10 years old."
As an adult, he often stocked up on junk food after work and ate almost all of it. Food controlled him so much, in fact, he felt the need to stop for food after getting off at midnight so he wouldn't have to go back out in the middle of the night.
Now 53, it took years of binge eating and yo-yo dieting to realize he had an addiction to food.
"I used food as a coping mechanism. It's similar to the way people use drugs, or alcohol, or shopping or sex."
That's an idea supported by a new study that found food may indeed be just like a drug.
Researchers led by Yale University doctoral student Ashley Gearhardt discovered that women who exhibit more signs of food addiction, when shown a picture of a milkshake and then given a taste of it, had more activity in areas of the brain associated with "craving" than women who showed fewer signs of food addiction. The women who showed more signs of food addiction had less activity in the part of the brain that decreases the desire to eat.
In order to measure food addiction, the researchers used a scale similar to the one used to measure drug addiction.
"We got interested in this research because there have been a lot of interesting findings in looking at parallels between obesity and substance dependence. Studies have shown brain pattern similarities," said Gearhardt.
"Anticipation of a delectable treat provided the greatest activation, even more so than getting a taste of it," said Bonnie Levin, director of the Division of Neuropsychology at the University of Miami School of Medicine. Levin was not involved in the study.
Food addicts exhibit many of the symptoms as those addicted to drugs and alcohol, including an obsession or preoccupation with food, binge eating and a lack of control over eating. Food addicts are often criticized about their inability to say no to overeating.
Not all food addicts are obese, and not everyone who overeats is a food addict.
"We saw the same brain activation patterns in lean participants as well as the obese ones," said Gearhardt. "BMI [body mass index] is not a good indicator about whether you're out of control with eating."
Experts say there's a lot of stigma surrounding food addiction, including the assertion that it's just an excuse for overeating and avoiding personal responsibility. In reality, food addicts are driven to eat.
"Part of the brain responds to anticipation of a reward," said Levin. "Some people can resist it and others cannot."
"I wanted no part of the realization that I had an addiction," said Prager. "Everyone thinks obesity is a matter of sloth and that obese people need to try harder."