Nicole Avena, PhD, is a neuroscientist at the University of Florida, where she studies mice to understand the effects of a sugar- and fat-rich diet. “We see changes in behavior, like binging, cravings, tolerance, and withdrawal signs, all of which are caused by not having access to palatable food,” Avena explained. These traits have not all been confirmed in clinical trials, but other researchers are finding preliminary evidence that some humans might also experience these classic behavioral signs of addiction in response to food.
Stice has also noted that obese people are extremely attentive to cues indicating a meal is on its way. Individuals who regularly overeat “become hypervigilant to food cues,” said Stice. Someone who loves McDonalds will immediately notice restaurants and advertisements, and will start craving a burger and fries; people who never eat there will sail past billboards on the freeway, oblivious to the ubiquitous golden arches. “That’s exactly what we see with drug abuse,” said Stice. “If you become a drug abuser, you become hypervigilant for cues that remind you of the drug: a mirror and a razor blade, if you’re a cocaine user. That makes you crave cocaine.”
Avena believes that understanding the parallels between overeating and drug use might help health professionals understand how to treat — and defeat — obesity. “We can use a lot of these things we’re learning from the science of addictive overeating and apply it to weight loss strategies that will work,” Avena said.
It’s important to remember that, while you should steer clear of junk food, a moderate amount of fat and natural sugars, like those found in fruit and nuts, are part of a healthy, balanced diet. Health experts recommend limiting your intake of solid fats and added sugars to no more than five to fifteen percent of your daily calories.
One way to regain control of your eating behavior is to lose weight. A recent study found that people who lost weight increased their availability of D2 receptors — the very same receptors that people lose access to as they gain weight. These results need to be confirmed in larger clinical trials, but the potential implications — that you can ditch your sweet tooth and retrain your brain — might lend hope to those who struggle with their weight.
While scientists have only recently started studying the ways junk food affects the brain, their findings are helping us come to a better understanding of how people become obese. Their insights — that junk food, like drugs, can hijack the brain — may one day inform the way we treat obesity. Research like this brings us one step closer to regaining control of the collective waistline of America — and stopping health problems before they start.
Published March 11, 2013.
Margot Hedlin is a health and science writer living in San Francisco.