Richard Montañez knows he’s cracked the code when his son Steven exclaims, “Ow, ow, ow, it burns!”
In the recently released film Flamin’ Hot, which tells Montañez’s account of how he allegedly invented Flamin’ Hot Cheetos, Montañez and his wife ask their son: “Burns good or burns bad?”
“Burns good,” little Steven replies, before reaching for a handful more of the spicy snack.
That spice, and the ensuing endorphin release, is part of what makes Flamin’ Hot Cheetos so tempting to devour handfuls at a time. But the science behind why Cheetos, and junk food more generally, are so addictive points at something much deeper.
Although processed foods – like canned beans and tinned fish – have long been a part of the American diet, food companies began engineering what experts call “ultra-processed foods” at an accelerated pace in the 1980s and 90s. These ultra-processed foods usually contain added sugar, salt, fat, artificial colors or preservatives, and aren’t made of food so much as substances “extracted from foods”, like hydrogenated fats, bulking agents and starches (think chips, frozen dinners, soda and fast food). Many of these foods have been optimized by food companies to hit the perfect level of sweetness (or saltiness) – nicknamed “the bliss point” – to keep consumers eating.
Today, ultra-processed foods make up 73% of the US food supply, according to Northeastern University’s Network Science Institute. Yet research has also linked ultra-processed foods to diabetes, obesity, cancer and other health conditions. Despite those health risks, the average adult in the US gets more than 60% of their daily calories from ultra-processed foods.
That’s largely because “highly processed foods can be addictive”, says Nicole Avena, a professor of neuroscience at the Icahn School of Medicine at Mount Sinai and author of the forthcoming book Sugarless: A 7-Step Plan to Uncover Hidden Sugars, Curb Your Cravings, and Conquer Your Addiction. “They can change the brain in ways that make it look like the person consuming them is actually consuming a drug. And that’s why so many people have a hard time having just one Cheeto.”
In the early 2000s, a Brazilian researcher named Carlos Monteiro began studying the effects of processing on food. Although some scientists – like Avena – had begun researching the addictive qualities of certain ingredients, like sugar, few had looked at the broader issue of how processed foods were put together. Monteiro and his colleagues at the University of São Paulo had noticed that, even though sugar consumption seemed to be going down in Brazil, rates of obesity and type 2 diabetes were increasing. So they decided to look not just at the ingredients but the amount of processing that went into the packaged foods that had begun appearing in supermarkets.
In 2009, Monteiro published a paper outlining a new method for categorizing the types of processed foods, which would come to be known as the Nova classification system. In the Nova system, categories one, two and three include less-processed foods, like raw vegetables and dried fruits (Monteiro calls these “unprocessed and minimally processed foods”), butter and salt (“processed culinary ingredients”), and smoked fish and pickled vegetables (“processed foods”). Meanwhile, Monteiro concluded, category four foods, or “ultra-processed foods”, are specifically engineered to be “edible, palatable, and habit-forming” and are “intrinsically nutritionally unbalanced”.
For many years, though, research only showed correlation, not causation, between ultra-processed foods and obesity. Kevin Hall, a scientist at the National Institutes of Health (NIH), was skeptical that processing was really to blame, and instead wondered if researchers were instead noting poor health outcomes tied to living in poverty. So, in late 2018, he designed the first randomized, controlled study to test whether ultra-processed food really did cause overeating.
Over the course of four weeks, 20 healthy adult volunteers agreed to eat either an ultra-processed or a minimally processed diet for two weeks, then switch to the other diet. Hall’s team made sure that both options were appetizing, and matched to include the same amounts of nutrients, like protein, fat, fiber and carbohydrates. Importantly, they also made sure that participants had more than enough food – and encouraged them to eat however much they wanted. By the end of the study, Hall found that volunteers had eaten 500 calories more each day during the ultra-processed diet weeks – and their bloodwork showed elevated levels of hormones responsible for hunger.
Hall’s study, says Leigh Frame, executive director of the office of integrative medicine and health at George Washington University, showed researchers that there was something unique about ultra-processed food that caused people to overeat.
“Have you ever sat down and eaten a dozen ears of corn? Probably not. But you could eat a whole bag of Doritos without a problem,” says Frame. “There’s something different about a whole food versus a processed food in terms of your ability to eat, but also the desire to.”
Cheetos themselves are especially addictive for all those reasons – and more. Cheetos are “one of the most marvelously constructed foods on the planet, in terms of pure pleasure”, food scientist Steven Witherly told the New York Times reporter Michael Moss in 2013. “If something melts down quickly, your brain thinks that there’s no calories in it … you can just keep eating it forever.”
It’s not just the fact that Cheetos, quite literally, melt in your mouth that make them so addictive. The sticky orange powder, according to researchers at the marketing group NeuroFocus, also elicits a powerful reaction from consumers – although they might act annoyed, their brains secretly delight in the mess. And a 2015 study from researchers at Oxford even found that crunchy snacks, like Cheetos, can trick your brain into thinking the food is fresher than it is.
Hall and his colleagues at the NIH are currently conducting another study to better understand why ultra-processed foods cause consumers to overeat. But in the meantime, there are baby steps you can take to decrease your dependence on ultra-processed foods. Frame suggests gradually working to eat more foods that fall in categories one, two or three of the Nova system – but emphasizes that “no food should be 100% off limits” because that makes it a “forbidden fruit” you’re more likely to crave.
Avena agrees: “I think one of the biggest problems people have is that they try to just, overnight, completely revamp their diet and throw everything out that’s bad and start fresh. And that really sets people up for failure because it’s too much at one time. You’re going to see long-lasting changes if you make small incremental steps.”
But she also adds that policymakers could find ways to better communicate the nutritional value of foods to consumers, like labeling how processed foods are on a scale like the Nova system. “Right now we’re leaving it up to the consumer to figure this out on their own. And that’s not fair.”