The urge to chow down on French fries is powerful. But a new study shows that some people may find the impulse more powerful than others. As reported by, the Scripps Research Institute says the same biological mechanisms that push people to drug addiction fuel the compulsion to overeat. What’s more, junk food addiction can be just as hard to kick as heroin.

With obesity at levels never seen before — and a fast-food restaurant seemingly waiting on every corner — these new findings may help explain why people have such a difficult time controlling how and what they eat. According to the New York Times, the Center for Disease Control and Prevention reports that almost 34 percent of adults are obese, more than double the percentage 30 years ago. At the same time, the number of obese children has tripled. These new findings may explain why.

The study from Scripps Research associate professor Paul J. Kenny and graduate student Paul M. Johnson goes beyond theoretical obesity rates. Apparently, rat models exposed to foods such as bacon, sausage and cheesecake revealed a deteriorating chemical balance. Just as with drugs, the pleasure centers of the rats’ brains became less responsive as the rats ate more high-fat, high-calorie junk foods. In order to avoid a “negative” state of mind, the rats over-consumed and became obese. 

The study lasted more than three years. According to the lead scientist, the study conclusively confirms the addictive nature of junk food. As Kenny points out, “It presents the most thorough and compelling evidence that drug addiction and obesity are based on the same underlying neurobiological mechanisms. In the study, the animals completely lost control over their eating behavior, the primary hallmark of addiction. They continued to overeat even when they anticipated receiving electric shocks, highlighting just how motivated they were to consume the palatable food."

The science behind this discovery deals with the levels of D2 dopamine receptors in the brain. These levels were significantly reduced in the brains of the obese test rats, just as they are with drug addicts. Experts say this is a result of constant stimulation. Once presented with a “salad bar” option, the rats refused to eat. Even when threatened with shock stimulation, the rats continued to gorge on the high-fat foods.

In the end, it seems junk food is as addictive as some of the worst drugs plaguing society. According to Kenny, the data is, “as far as we know, the strongest support for the idea that overeating of palatable food can become habitual in the same manner and through the same mechanisms as consumption of drugs of abuse." 

For further reading: Study shows compulsive eating same addiction has heroin, cocaine abuse.

Junk food junkies are real addicts
New study finds the same chemical mechanisms that push people to drug addiction fuel the compulsion to overeat.