Are ultraprocessed foods truly addictive?

When I sat down to write this story, I remembered the gummy worms in the snack drawer of my kitchen. So I got up and grabbed a handful. I should add that I had just finished lunch, and I don’t really like gummy worms.

And yet, I ate them.

That’s not an unusual moment in my life, and maybe in yours too: eating a treat that serves almost no nutritional purpose. My treat, for instance, had sugar but little else of substance on the ingredient list: gelatin, natural and artificial flavors, carnauba leaf wax and colors, including Red 40, Yellow 5, Yellow 6 and Blue 1. As I read the list in growing disgust, I helped myself to another worm.

But after reporting this story, I’m going to cut myself some slack. There’s growing recognition that these sorts of highly processed foods are engineered to make us want more. Like gummies stuck in the teeth, foods high in sugary, crunchy, salty, creamy or savory qualities can stick in our brains and urge us to eat another handful.

These foods, scientists are increasingly convinced, have addictive properties, similar to the pulls created by alcohol, nicotine and opioids. And certain kinds of engineered foods, usually combinations of salts, fats and sugars, create such a strong desire to eat them that they could be classified as addictive substances.

Highly engineered foods can worm their way into the brain’s reward system, triggering powerful “eat more” signals. Studies suggest ultraprocessed foods can lead to cravings, loss of control, withdrawal and tolerance — all hallmarks of a substance use disorder.

There are still lots of questions about exactly what these foods do to us, who is most at risk of overeating them, and what strategies might empower us to wrestle back control. Yet questions about how these increasingly abundant food products affect our brains and the rest of our bodies are more important than ever. A big chunk of the U.S. diet — over half of the calories Americans eat, on average — is now categorized as “ultraprocessed.”

Ultimately, the goal of research on food and addiction is to give people a better understanding of how what we eat affects us so we can make informed decisions, says neuroscientist Alex DiFeliceantonio of the Fralin Biomedical Research Institute at Virginia Tech Carilion in Roanoke. But there’s a competing goal at play here, she says: “The goal of a food company is to have you eat more food.”

Writing in Nature Medicine this summer, addiction and nutrition experts including Nora Volkow, the director of the National Institute on Drug Abuse, make the scientific case that these food products “share more commonalities with addictive substances than they do with naturally occurring foods.” It’s time, they write, for policy makers and scientists to recognize the danger — and do something about it.

Are ultraprocessed foods even food?

Like anyone who eats — which is to say, everyone — I thought I had a pretty good handle on what food is. But it turns out that my handful of cheese puffs doesn’t really count, according to Ashley Gearhardt, a psychologist at the University of Michigan in Ann Arbor.

“This stuff isn’t food. It’s a hedonically optimized substance created through processing to make corporations a lot of money,” she says. “We shouldn’t give [ultraprocessed foods] a pass just because they have calories.”

Neuroscientist Nicole Avena of Icahn School of Medicine at Mount Sinai in New York City has her own questions about the vocabulary at work here. “I don’t even know if we should be calling them food anymore,” she says. “So I’ve been referring to them as foodlike products.”

But if these “foodlike products” aren’t food, what are they?

The term “ultraprocessed food” is, in many ways, as squishy as a pale yellow Peep. For decades, food scientists have been tinkering with ingredients, preservatives, colorings, bulking agents and more to keep food unspoiled, visually appealing and delicious.

Scientists often use the NOVA classification system to sort foods into four categories: unprocessed or minimally processed (an apple, for instance, or chicken); processed cooking ingredients (sugar or butter); processed foods (cheeses or canned vegetables); and ultraprocessed foods (hot dogs or potato chips).

Ultraprocessed caloric conglomerates “basically contain limited to no whole food pieces or products and contain additives,” says Tera Fazzino, a psychologist at the University of Kansas in Lawrence.

These products are built piecemeal from sugars and fats that have been taken from their naturally occurring form and then concentrated and packaged into something new, often with additives to improve the flavor and mouthfeel. Then they’re packaged into an appealing wrapper with a recognizable logo.

“Just as a cigarette has little in common with a tobacco leaf, an Oreo shares few characteristics with the corn and soybeans from which it was made,” Volkow, Gearhardt and others write in their Nature Medicine piece.

These foods have been around for decades, and they’re everywhere. In 2003, ultraprocessed foods accounted for about 51 percent of people’s calories at home. By 2018, the percentage had risen to just over 54.

In 2019, Fazzino and her colleagues wrote a paper describing a related but not completely overlapping definition: hyperpalatable. It means what it sounds like: extra delicious, irresistible, yum. Fazzino points out that regular old foods that everyone can agree are foods — apples, carrots, salmon — are also palatable, and they also carry signals of reward. But hyperpalatable foods are next level.

Take children’s breakfast cereal. A recent study found that from 2010 to 2023, fiber and protein went down in U.S. cereals, while fat, salt and sugar increased. Those results, published May 21 in JAMA Network Open, are but one example of the larger shift toward increased fats and sugars and away from nutrients. And removing ingredients like fiber that make us feel full while increasing the ones that scream “delish” is a recipe for eating too much.

“In the U.S. food system, there’s a pretty strong degree of overlap” between hyperpalatable and ultraprocessed food, Fazzino says. In some other countries, there was less overlap, Fazzino and colleagues reported June 6 in PLOS One. Perhaps that’s because food processing in some places outside the United States can be less intense.

“They do something to it and they stick in a package,” Fazzino says. That’s not the same thing as making the food taste deliriously delicious.

A brief history of addiction and food research

Decades ago, food and addiction were seldom mentioned together. But around 2007, food policy expert Kelly Brownell, then at Yale University, and addiction researcher Mark Gold, then at the University of Florida, began talking about the intriguing links. Their conversations led to a two-day meeting at Yale University in the summer of 2007 that forced the fields of addiction and nutrition together — the first meeting of its kind.

Half the people invited were from the nutrition and obesity field, and half were from the addiction field, Brownell says. There was some skepticism at first that the idea was legit, that addiction could be a helpful framework when it came to food.

“The people from the addiction field were much quicker to embrace the concept that food could be triggering addictive processes than the people in the nutrition field,” Brownell says. “And the reason I think is that it was newer to the people in the nutrition field. They weren’t used to thinking about the concept of addiction.” But over the years, the idea that foods, particularly ultraprocessed foods, could spur addictive responses in people became more widely accepted.

As a grad student in the 2000s, Avena found that sugar use shared characteristics consistent with addiction, based on criteria set forth at that time in the Diagnostic and Statistical Manual of Mental Disorders, or DSM, a handbook for psychiatrists that described substance use disorders.

“It was a little bit, I would say, tumultuous in the beginning, because nobody was really keen on this idea,” she says. But the research moved forward, much of it pointing to parallels with other addictive substances. A key piece of the argument lies in the reward regions of the brain, including the striatum, a well-connected, deep part of the brain that influences motivation and good feelings. The striatum can signal when things are beneficial to the body. A stash of honey, with its burst of calorie-dense sweetness, would kick off a big reward signal in the brain of a hungry person.

Neuroscientists have been amassing evidence from animal studies and people that shows how ultraprocessed foods change the brain in ways that are reminiscent of other addictive substances. Studies have uncovered detailed neurochemical effects, structural changes and alterations in key brain regions’ activity.

“When we look in the brain, there are neurochemical changes that happen in response to food that are very much like what you would see in response to drugs or alcohol,” Avena says. Scientists have found changes in the brain’s reward systems, including the chemical messengers dopamine, serotonin and brain-made opioids. Many of these changes, researchers suspect, all conspire to make a person be more alert to food.

DiFeliceantonio and her colleagues found, for instance, that people who were given a high-fat, high-sugar yogurt dessert daily for two months had stronger neural reactions to food cues in brain areas that handle reward. The dessert essentially rewired the reward circuitry in these volunteers, boosting their motivation for eating treats. In further experiments, these people also performed better in laboratory tasks of learning, to DiFeliceantonio’s utter surprise.

Why you just can’t stop

Yet substance use disorders are much more complex than what can be measured in experiments by brain scientists. They involve combinations of behaviors, emotions, triggers and history. These include intense cravings, repeated attempts to stop and continued use despite being well aware of the damage.

Gearhardt is an addiction clinician, and she sees patients who will tell her that they are struggling with these foods. “They’re saying, ‘I’m addicted to this stuff, I am telling you I’m addicted … I know it’s killing me. I’ve got diabetes, I’m going blind, and I cannot stop.’ And people would just tell them, ‘No, you’re wrong, you just have to try harder, count your calories, do your macros.’ ”

Listening to those experiences solidified her perspective that there is something pernicious about these foods. Running through the checklist of substance use disorders in its current form in the DSM, some people meet the benchmarks for problematic behaviors and symptoms around ultraprocessed foods, researchers argue. That’s based on nearly 300 studies from 36 countries.

Using the Yale Food Addiction Scale, about 14 percent of adults and 12 percent of children meet the criteria for food addiction, a figure that’s very close to the estimate for alcohol use disorder prevalence. The survey includes questions about eating habits, such as whether a person overate to the point where they felt ill, and whether a person had strong urges to eat.

In a set of preliminary findings, DiFeliceantonio and colleagues found that 18- to 21-year-olds on an ultraprocessed diet ate more than the same cohort on a minimally processed diet. And they ate more in the absence of hunger. The same wasn’t true for slightly older adults who were ages 22 to 25. Figuring out who might be more affected by different types of food is still a big question.

Should ultraprocessed foods be regulated?

With growing recognition of how ultraprocessed foods have been designed and perfected to keep us snacking, attempts to cut back can feel futile. That’s especially true when many people live in places without access to healthy, fresh food. Even if unprocessed foods were readily available, they can be costly and take up more time and space to prepare. 

But there has been some progress. Federal agencies are scrutinizing these foods, with childhood nutrition as a focus. States are exploring bans on ultraprocessed foods in schools. And a lawsuit was brought in Pennsylvania against food companies that are accused of knowingly hooking people on their products despite being aware of the harms. The suit has since been dismissed, but similar efforts might follow.

After tobacco products got more tightly regulated, many of those companies pivoted to food products, Fazzino says. Researchers studied foods for sale from 1988 to 2001. Over time, tobacco-owned food companies were more likely to sell hyperpalatable foods than food companies with other types of owners, researchers reported in 2023 in Addiction. “U.S. tobacco companies were systematically involved with the development and the dissemination of these foods into our food supply,” Fazzino says.

Now there are movements to improve school lunches, movements to promote better labeling and movements to educate people about how to spot unhealthy foods that have been “healthwashed” by companies.

“I don’t even know if we should be calling them food anymore. So I’ve been referring to them as foodlike products.”

Nicole Avena
Neuroscientist

Efforts to regulate ultraprocessed food products are pushing ahead whether experts consider these foods addictive or not. When I asked DiFeliceantonio why the addiction lens matters, she replied: “It comes back to this idea of us making decisions in a difficult environment.” If a substance is designed to be irresistible, then “decisions actually are no longer your own because they’re being governed by your drug, by your substance,” she says. “And so if these foods are addictive, we can’t make good decisions about them.

“We have enough data at this point to understand that ultraprocessed foods, on the population level, are killing us, are leaving us to live shorter lives with a higher disease burden, and we’re telling people, ‘Well, stop eating them,’ ” she says. But through an addiction lens, that strategy falls short. 

What’s more, so much of normal or abnormal behavior is a social construct, Avena says. “So if it’s socially acceptable to drink alcohol, then that’s fine, right? But it’s not socially acceptable for 6-year-olds to drink alcohol, right?” It’s the same with processed foods, she says. “I think they become so socially acceptable to have these foods all the time, to bring them to parties, to give them to our kids, that it’s basically become normalized.”

Change may come from a growing recognition of the potential harms from eating ultraprocessed foods, Avena says. “If you know there’s a risk associated with it, then that makes you think twice.”

Some food companies are already working to unprocess their products in response to public pushback, Avena says. “I think if enough people start to say, you know what? I don’t want all these donuts for my kids for their lunchbox, or I don’t want Lunchables.… I want a healthier version of it. I want something that is going to be less processed. I think that the companies will have to step up to the plate, and you see that happening,” Avena says. At food shows, she’s already seen examples of smaller companies trying to design and market nutritious food. Foods designed for people on GLP-1 drugs that are high in protein and not too sweet or processed are already being created and sold.

But the most effective avenues for change may be stronger regulations that mandate healthier food, tax unhealthy food and require better labeling. In Chile, aggressive rules for packaged foods high in sugar, saturated fat, salt or calories — in other words, many ultraprocessed foods — are already yielding progress, Brownell says. That country has restricted marketing, added taxes on certain products and mandated glaringly obvious warning labels. These efforts seem to be shifting people’s purchases. A recent study found that less sugar, salt, saturated fat and total calories from products marked with warnings found their way into people’s cabinets.

“The more that the conversation is shifted to the individual and away from the actual source of the problem, which I think is the addictive foods, then we don’t have a real solution,” Fazzino says. “As a public, we deserve to be protected from the things that can cause us harm.”