Despite being linked to health issues including obesity and heart disease, highly processed foods account for more than half the calories Americans consume—but experts are divided on whether it's possible to become physically addicted to them.

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Why some experts believe junk food can be addictive

In a 2015 study published in PLOS One, researchers found that certain foods—including pizza, chocolate, potato chips, cookies, and ice cream—were more likely to elicit "addictive-like" eating behaviors, such as strong cravings and an inability to reduce consumption despite harmful consequences.

In separate research, Ashley Gearhardt, director of the Food and Addiction Science and Treatment Lab at the University of Michigan and an author on the study, found that highly processed foods have many commonalities with addictive substances. 

For instance, much like cigarettes and cocaine, the ingredients of highly processed foods come from naturally occurring plants and foods but are stripped of components—such as fiber, water, and protein—that slow absorption. And the ingredients that provide the most pleasure tend to be refined and processed into products that quickly enter the bloodstream, which in turn bolsters their ability to activate parts of the brain regulating reward, emotion, and motivation.

That quickened ability to reach the brain is often associated with addictive behavior, Michael Moss, a reporter and author of multiple books on food marketing, said. According to Moss, addiction science in the 1990s discovered that "the faster a substance hits the brain, the more apt we are as a result to act compulsively, impulsively"—and there is "nothing faster than food in … its ability to sort of hit the brain."

Separately, Gearhardt added that highly processed food is also similar to other addictive substances in that they often contain other additives. Much like how the use of menthol in cigarettes increases the potential for addiction, highly processed foods typically contain artificial flavors, thickeners, and salt, which enhance properties of food such as mouth-feel and texture.

Moreover, highly processed foods generally contain large quantities of fat and refined carbohydrates, a combination that typically doesn't occur in nature, Gearhardt said.

"People don't experience an addictive behavioral response to naturally occurring foods that are good for our health, like strawberries," she said. "It's this subset of highly processed foods that are engineered in a way that's so similar to how we create other addictive substances. These are the foods that can trigger a loss of control and compulsive, problematic behaviors that parallel what we see with alcohol and cigarettes."

According to the Times, another study conducted by Gearhardt published in the journal Appetite found that when people try to stop eating as many highly processed foods, they usually have symptoms similar to the withdrawal experienced by those trying to stop misusing drugs, including irritability, fatigue, cravings, and feelings of sadness.

Why other experts say junk food is not addictive

However, other experts, such as Johannes Hebebrand, head of the department of child and adolescent psychology, psychosomatics, and psychotherapy at the University of Duisburg-Essen in Germany, say no food is physically addictive in the way that drugs are. 

According to Hebebrand, eating food doesn't create an altered state of mind like other addictive substances do.

"You can take any addictive drug, and it's always the same story that almost everyone will have an altered state of mind after ingesting it," he said. "That indicates that the substance is having an effect on your central nervous system. But we are all ingesting highly processed foods, and none of us is experiencing this altered state of mind because there's no direct hit of a substance in the brain."

In addition, in instances of substance use disorders, people become dependent on a specific chemical that acts on the brain, such as nicotine or ethanol, Hebebrand said. However, there isn't a compound in highly processed foods that can be singled out as addictive.

For his part, Hebebrand said he believes that part of what drives overeating is efforts by the food industry to advertise and market more than 20,000 new food products a year. "It's the diversity of foods that is so appealing and causing the problem, not a single substance in these foods," he said.

How to minimize cravings for junk food

But whether or not junk food is truly addictive, how can you cut back on your consumption if you choose to do so?

Gearhardt advised keeping a journal to identify the foods that incite the most cravings. She recommended that people keep those items out of the house and instead stock their pantry with healthier options they still enjoy.

In addition, Gearhardt recommended monitoring what triggers cravings and binges, whether that be an emotional state such as boredom, or a physical landmark such as a nearby fast-food restaurant. According to Gearhardt, people can manage those triggers by exploring other ways of alleviating difficult emotions or simply taking a different route home.

She also recommended eating healthy foods regularly, rather than skipping meals. "Making sure you are regularly fueling your body with nutritious, minimally processed foods that you enjoy can be important for helping you navigate a very challenging food environment," she said (O'Connor, New York Times, 2/18; Davies, "Shots," NPR, 4/26).