Is Junk Food Addictive?

The notion that junk food, like narcotics, is addictive and that this addiction explains the national crisis in obesity is gaining traction. Findings based on research with rats reported in Science News provide worrisome support for this idea.

Rats fed a diet rich in junk food (processed cakes, sausage, bacon, cheesecake, etc.) quickly adopted the habits of drug addicts. They wanted more and more junk food and needed more and more to feel normal; they refused to eat regular food once they were hooked on the rich, sweet food even if rejecting normal food meant starving; they continued to eat junk food even when consuming it triggered an electric shock to their feet; and once they went back to rat chow, their bodies took a long time to recover. In fact, some never did return to normal eating habits.

Tests on the rats’ brains and intestines during and after the rats consumed junk food showed biochemical changes. Researchers concluded that the brains and digestive systems of the rats had become captive of the chemical changes resulting from eating junk food—the very definition of addiction. And like drug addiction, junk food addition can produce changes that are difficult to unwire.

If the experiment with rats is predictive of human behavior, then the chemical changes in the rats’ bodies and the rats’ addictive habits could explain the growing problem of obesity in the United States. As we consume more and more rich, sugary food, we will want more and more, and we’ll gain more and more weight.