Recent studies have found that about twenty-seven percent of American adults are obese. Obesity rates have grown substantially in past decades and continue to be on the rise. The consumption of junk and fast food has played a major part in these statistics. Ten years ago, scientists suggested that junk food might be addicting but it was not widely accepted. Now, scientists have begun to prove that junk food can be addictive, with its high salt, sugar, and fat contents. Although there are other factors to addiction
, such as family history, stressful situations, and inability to cope with reality, the content of the food does play a part.
In 2001, Nicole Avena from the University of
and Bartley Hoebel from Princeton studied the various reactions of rats when given sugar. Along with water and normal rat food, they gave the rats sugar syrup. After just a month on the diet, the rats began to change their behavior. According to Avena and Hoebel, the rats exhibited behavior very similar to that of morphine-addicted rats. Upon removal of the sugar syrup, the rats exhibited anxiety and irritability, common signs of withdrawal. Finally, the brains of the rats consistently released dopamine when drinking the sugar syrup. Dopamine is a neuro-chemical that controls pleasure-seeking, and is a hallmark of the drug addict.
With the evident findings of the 2001 study, experts became more open to the idea of junk food actually being addictive. Studies in more recent years have shown that when junk food lovers are shown a piece of their favorite food, certain parts of their brain release dopamine, namely the decision-making portion. Similarly, when a cocaine addict is shown a bag of cocaine, the same areas of the brain have the same reaction. Interestingly enough, these results did not apply solely to obese testers, although overweight individuals were more likely to release dopamine upon the presence of food. People who were fit, but had obese parents were also highly likely to have the same reaction. The part where addiction truly develops is found in the tolerance built to the dopamine release. As an individual begins eating junk food more often, the body does not release as much dopamine, therefore decreasing the pleasure gained. In order to achieve the same level of pleasure, the person must increase their intake of junk food. The brain is accustomed to having dopamine released, so the person is compelled to eat to the point of the same release levels. It is strikingly similar to the way a drug addict begins using more and more drugs to achieve the high they once gained.