In her clinical practice, Dr. Gearhardt has encountered patients — some obese and some not — who struggle in vain to control their intake of highly processed foods. Some attempt to eat them in moderation, only to find that they lose control and eat to the point of feeling ill and distraught. Many of her patients find that they cannot quit these foods despite struggling with uncontrolled diabetes, excessive weight gain and other health problems.
“The striking thing is that my clients are almost always acutely aware of the negative consequences of their highly processed food consumption, and they have typically tried dozens of strategies like crash diets and cleanses to try and get their relationship with these foods under control,” she said. “While these attempts might work for a short time, they almost always end up relapsing.”
But Dr. Hebebrand disputes the notion that any food is addictive. While potato chips and pizza can seem irresistible to some, he argues that they do not cause an altered state of mind, a hallmark of addictive substances. Smoking a cigarette, drinking a glass of wine or taking a hit of heroin, for instance, causes an immediate sensation in the brain that foods do not, he says.
“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,” said Dr. Hebebrand. “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 substance use disorders, people become dependent on a specific chemical that acts on the brain, like the nicotine in cigarettes or the ethanol in wine and liquor. They initially seek out this chemical to get a high, and then become dependent on it to alleviate depressed and negative emotions. But in highly processed foods, there is no one compound that can be singled out as addictive, Dr. Hebebrand said. In fact, evidence suggests that obese people who overeat tend to consume a wide range of foods with different textures, flavors and compositions. Dr. Hebebrand argued that overeating is driven in part by the food industry marketing more than 20,000 new products every year, giving people access to a seemingly endless variety of foods and beverages.
“It’s the diversity of foods that is so appealing and causing the problem, not a single substance in these foods,” he added.
Those who argue against food addiction also point out that most people consume highly processed foods on a daily basis without showing any signs of addiction. But Dr. Gearhardt notes that addictive substances do not hook everyone who consumes them. According to research, about two-thirds of people who smoke cigarettes go on to become addicted, while a third do not. Only about 21 percent of people who use cocaine in their lifetimes become addicted, while just 23 percent of people who drink alcohol develop a dependence on it. Studies suggests that a wide range of factors determine whether people become addicted, including their genetics, family histories, exposure to trauma, and environmental and socioeconomic backgrounds.