NAT GEO * Are ultra-processed foods as addictive as cigarettes? *

Junk foods like candy and chips trigger cravings—a key feature of addiction. Experts say that the food industry applied lessons learned from Big Tobacco to ultra-processed foods.




ByMeryl Davids Landau
May 28, 2024






Who hasn’t had the sensation of tunneling through a large bag of potato chips or eating more donuts than intended? A growing body of evidence shows that this phenomenon isn’t due to a lack of willpower—it may be caused by a condition called ultra-processed food addiction.
Highly processed foods are addictive for some people because they trigger the cravings, compulsive consumption, and other traits associated with tobacco or alcohol substance use disorder. In fact, up to 20 percent of adults and 15 percent of kids and adolescents have signs of addiction to ultra-processed foods.
Ultra-processed foods are manufactured inside industrial factories—not your grandma’s kitchen—and they contain ingredients that are altered and combined in ways that amp up their fat, sugar, and/or salt content. They also include multiple other flavor and sensory enhancers to make them so enticing that people can’t resist, says Evan Forman, a professor of psychological and brain sciences at Philadelphia’s Drexel University who has studied food addiction.
These foods include packaged snacks; ready-to-eat breakfast cereals; most fast foods; mass-produced breads and desserts; reconstituted fish and meat products like sausages, hot dogs, and fish sticks; soft drinks; ice cream and candies; and many other packaged products found in the middle aisles of a grocery store. They are estimated to comprise close to 60 percent of the calories consumed in the United States.
“I don't think people realize that a lot of the time they're not deciding what they eat in the way that we think of free will,” Forman says. “These foods just activate our brain’s reward system so powerfully.”

When three dozen international experts gathered in mid-May for the International Food Addiction Consensus Conference in London, they found “sufficient evidence” that people can become addicted to ultra-processed foods and that this can occur with or without other eating disorders like binge eating (although people with these conditions suffer disproportionately).

Triggering the brain and the gut

The notion that certain foods can lead to addictive behaviors has been around for several decades, since rat studies in the 1980s showed that activity in the dopamine reward system in their brain increased substantially when they pressed a lever for a food reward. It was a similar reaction (albeit not as intense) to when they self-administered cocaine.

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But in the past decade, with Americans’ obesity rate skyrocketing to 42 percent— with the highest levels in people who identify as Black or Hispanic—scientists started evaluating which changes in the food environment could be causal, and the impact of ultra-processed food addiction could no longer be ignored.
For most of human history, survival depended on being sufficiently motivated to leave the home to seek out an assortment of fatty and sweet foods, which evolution rewards with feel-good chemicals like dopamine.
“In a food environment that’s laden with ultra-processed foods, the brain is confusing experiences and substances that are harmful for experiences and substances that are survival-promoting,” says David Wiss, a registered dietician and food-addiction researcher in Los Angeles who participated in the London conference.

Ultra-processed foods “deliver unnaturally high doses in an unnaturally fast way, often in unnaturally high combinations of rewarding ingredients,” says Ashley Gearhardt, a psychology professor at the University of Michigan and a key researcher in the field.
In addition to brain chemicals, recent research also implicates the gut microbiome. Large-bodied people with an addiction to ultra-processed foods are more likely to have a microbial composition similar to that of people with other addictive tendencies.

Meeting tobacco addiction criteria

Craving is a key feature of addiction, and it’s readily seen with ultra-processed foods, Gearhardt says. “You won't drive out of your way to get a head of broccoli, but people say, I was craving a Krispy Kreme donut, so I drove 40 minutes—even though I didn't have gas money—to eat a whole box of it in the parking lot, even though I have type 2 diabetes,” she says.
Withdrawal symptoms are another component of addiction. A research update published in May that Forman coauthored found preliminary evidence for withdrawal symptoms when ultra-processed foods are withheld.
“The extent to which you could see rats’ teeth chattering or people complaining of headaches, fatigue, and irritability when they stopped eating these foods…that was surprising to me,” Forman says.

A study Gearhardt published in 2022 applied the same criteria to these foods used in the 1988 U.S. Surgeon General’s report to determine whether tobacco products were addictive. It concluded the foods meet all criteria. Ultra-processed foods can trigger compulsive behaviors, Gearhardt found, pointing to studies where obese rats ignored their standard food and risked electric shock to get to industrial produced cakes and chocolates. The foods are sufficiently rewarding to drive repeat consumption. And they yield mood-altering effects, with “euphoria” scores after eating some foods like that following nicotine injection in smokers.




Because ultra-processed foods are manufactured to yield complex tastes, scientists are unclear whether all or just some of the ingredients have addictive properties.
They do know that food companies learned from cigarettes, especially after tobacco giant Phillip Morris Companies acquired two food companies in the late 80s to form Kraft General Foods (now called Kraft Heinz). Expertise and resources were transferred to the food company, especially regarding how to market the products to minority groups, researchers found.

Unhealthy and easy to overdo

High consumption of ultra-processed foods has been linked to numerous health problems, including greater risks of heart disease, type 2 diabetes, obesity, depression, anxiety, and death from all causes. A study published in May found higher levels of unhealthy cholesterol and glucose in children who eat more of these foods.
Weight gain often results from their consumption, likely because it’s easy to eat more than you intend. When 20 people were randomized to either ultra-processed or unprocessed diets for two weeks and instructed to consume as much as they wanted, the ultra-processed group ate 500 more calories each day.
(How ultra-processed food harms the body and brain)
But thin people can also become addicted. “There are people in ‘normal weight ranges’ and even underweight ranges that have these symptoms,” Wiss says, who perhaps work off the extra calories at the gym or who may not be genetically prone to becoming large-bodied.
One of the biggest problems is that people become familiar with the intense flavors and mouthfeel and become less satisfied with whole foods.
“The real consequence is we have teenagers growing up who are completely turned off by lentils and broccoli,” Wiss says.
National Geographic reached out to major food companies Kraft Heinz, General Mills, and Unilever for comment and received a single response from their trade group, the Consumer Brands Association.
“Demonizing shelf ready foods could limit access to and cause avoidance of nutritious foods,” it states. “Empowering consumers with clear nutritional information and preserving consumer choice so they can make the right decisions for their personal health goals should be the priority in public health guidance.” The group also notes the term ultra-processed doesn’t have a clear definition and “could lead to consumer confusion.”

Taking back control

Clear nutritional information is something Gearhardt desires, with mandatory packaging warning labels like those required for cigarettes. Until that happens, though, consumers are on their own and should try to choose foods with the fewest unnatural ingredients. Stopping the marketing of these products to children is also paramount, Gearhardt says.
Ultra-processed foods are popular in part because they are so convenient. You can buy them from vending machines and gas stations, and grabbing fast food seems smart when you don’t have time to cook from scratch. That’s why Gearhardt dreams of the day when local chefs deliver weekly whole-food dishes to people, subsidized by health insurance companies who currently foot the bill for resulting diseases.
How to treat people with severe food addictions is an open question. Some point to the effectiveness of GLP-1 drugs like Ozempic, which users say reduce craving for highly palatable foods. (The shots also reduce cravings for alcohol, supporting the notion of a common brain addiction pathway.)
(The unexpected health benefits of Ozempic and Mounjaro)
Preliminary evidence of benefits from a study Wiss coauthored points to success for weekly group and individual educational and psychological support alongside a whole-food eating plan.
“This is very different from traditional diet advice where we tell you what to do… and if you don’t succeed, you have to try harder. This is offering support based on the assumption this is a brain disorder that needs consistent behavioral modification, insights, and community, all to support the rewiring of the brain,” Wiss says.
Gearhardt is optimistic that the dangers of ultra-processed food will become well known, just like the dangers of smoking.
“Smoking was once so common and a huge part of Americana that we were numb to the fact that people were dying,” Gearhardt says. “I think we will wake up to the dangers posed by ultra-processed foods as well.”