People Are Addicted to Food
Author: Melissa Lahti
March 25, 2013
Obesity has become an epidemic in America with 66% of American’s being classified as overweight or obese. There is no known cause for this but we can assume that the exposure we have to calorie-dense foods and too little activity has a hand in it. I read an article that suggested once people start eating certain foods, they can become addicted to it. The person then has no choice but to come back for more as the dopamine levels in the brain actually drop causing the person to never feel satisfied.
Psychologists have developed a list with seven criteria to identify a person with an addiction. If a person meets three of the criteria on the list within one year, they are considered to be dependent. Technically there is no such disease as “food addiction” although, people have been found to meet the criteria for being an addict. One study applied the psychologist’s list to eating and obesity. They surveyed about 350 Yale undergraduates and 11% met the criteria for “food addiction”.
In 2001 a study was done to compare Dopamine and Obesity. Surprisingly, dopamine levels in obese people were lower than those of normal weight people. It was originally thought that an obese person would have high levels of dopamine that would make food more pleasurable although, it was found to be the exact opposite. Having low levels of dopamine causes a person to want more food because they are never satisfied with what they get and always want more. This is the same with drug and alcohol addicts.
These findings caused researchers to take a look at Dopamine responses before obesity set in to decide if a person becomes obese because of low levels of Dopamine or if they obtain low levels because they over ate and therefore over stimulated their Dopamine receptors. In one study they fed junk food to rats. The rats Dopamine levels went up until the rats became obese, at which point the levels dropped. To determine if being overweight caused the levels to drop they took two groups of rats and fed one junk food and the other the same amount of calories but with rat chow. The rats that were fed the junk food experienced the drop in Dopamine and the other rats did not.
Researchers are currently in the process of doing a similar study with a group of teens that are at risk of being overweight and teens that are normal weight. So far it looks as if they are going to get the same response as with the rat study. Rats have also been proven to become addicted to sugar and fat, even exhibiting withdrawals when the sugar is taken away. Looking at the results of these studies I would think it is safe to say, people have become addicted to calorie-dense foods, junk foods, sugar, and fat and therefore are becoming obese because they literally cannot stop eating.
CDC United States obesity map. 1990, 2000, 2010