Being severely overweight has never been so dangerous. During the COVID-19 epidemic, Americans who are obese, without any other risk factors, were hospitalized at three times the rate of those who weren't, by some estimates. When combined with other diet-related health conditions such as cardiovascular disease and diabetes, obesity raises the risk of hospitalization sixfold and the risk of death twelvefold.

Those numbers have raised the stakes in the nation's epidemic of diet-related disease and added to the growing alarm of politicians and nutrition experts, some of whom are starting to call upon regulators to rein in food companies. They're pushing measures similar to those used to curb the influence of tobacco companies in the 1990s, such as limiting the marketing of certain kinds of food to children and actively discouraging the consumption of key ingredients—chief among them, sugar.

At issue is the explosive growth in a broad class of food products that are not merely processed in the conventional sense to lengthen shelf life, but are also often modified to maximize flavor, visual appeal, texture, odor and the speed with which they are digested. These foods are made by deconstructing natural food into its chemical constituents, modifying them and recombining them into new forms that bear little resemblance to anything found in nature. So radically are they altered that nutrition scientists have given them a new name: ultra-processed.

Ultra-processed foods are often designed to directly target the vulnerabilities of the human brain—in particular, to exploit the way the brain processes pleasurable sensations. They often deliver a signal to the brain's reward centers so quick and potent, some neuroscientists believe, that many people find it as addictive as opioids or nicotine.

Lab-made creations such as chips, hot dogs, enriched bagels and American cheese have been a staple of the American diet since the 1980s. In recent years, however, the varieties of these foods have multiplied on store shelves and in fast-food restaurants. In 2017 and 2018, they accounted for 57 percent of the calories consumed by the average American—up from 54 percent in 2001 and 2002, according to one study.

"We've gotten really good at stripping out and refining and processing sugars and fats into these really potent vehicles, and they've gotten cheaper to make," says Ashley Gearhardt, a psychology professor at the University of Michigan who studies food and addiction. "Then we combine them into totally novel food products that are so much more rewarding than anything our brains ever evolved to handle. That's why so many of us can't stop eating them."

The implications are worrisome. Half of American adults now have diabetes or pre-diabetes, three quarters of adults are overweight and about 100 million, or 42 percent, are obese, by the standards of the Centers for Disease Control and Prevention (CDC). Among children between 2 and 5 years old, one in 10 are already obese. Among teens, that number is one in five.

Our food, in other words, is literally killing us. Food companies have tricked our brains into making us complicit, and our elected officials are complicit, too. What's needed is a better understanding of exactly how processed foods make us sick and a public reckoning with Big Food's role in the nation's health crisis. So far, policymakers have shown little appetite for scrutinizing the tactics of the powerful food lobby, but the pressure to curb consumption of ultra-processed foods is growing.

The nation's food crisis seems to be playing out in ways eerily reminiscent of the early days of tobacco smoking more than half a century ago, before regulators caught up with Big Tobacco. (It's no coincidence that many tobacco companies later acquired food companies.) This time, it's Big Food peddling harmful and possibly addictive products.

"We have now the accumulated evidence, particularly in the last five years, that people who eat more ultra-processed foods have higher risk of obesity, diabetes, cardiovascular diseases, depression, cancer, renal and liver diseases," says Marion Nestle, a professor emerita of nutrition, food studies and public health at New York University. "The studies have been overwhelming. There've been hundreds and hundreds of them. There's no doubt that this is not a good thing. It is a problem."

Proof of Harm

A few years ago, Kevin Hall set out to debunk the theory, espoused by a growing number of nutritionists, that Americans were getting fatter and sicker because of the complex industrial and chemical processing that food companies were using to make their products appealing. Hall believed the explanation had more to do with Americans simply eating too many calories, fats and sugars. The notion that extra processing might be causing the problem struck him as "ridiculous."

To prove it, Hall, who runs a research laboratory that studies the regulation of metabolism and body weight at the U.S. National Institutes of Health (NIH), ran a controlled experiment that he thought would show beyond a doubt that processing wasn't as important as nutrients. He paid 20 volunteers $5,000 apiece to move into an NIH facility in Bethesda, Maryland, for one month. He divided the volunteers into two groups. One ate mainly healthy food derived from simple ingredients with minimal processing, such as Greek yogurt, beef tender roast and shrimp scampi with spaghetti. The other group ate Honey Nut Cheerios, Chef Boyardee beef ravioli, Eggo pancakes and other processed foods—the kind most overweight people in America eat.

Hall and his colleagues did their best to ensure that the only significant difference between the two groups was in how much processed food they consumed. Each group ate diets that were nutritionally identical in every way Hall and his team could think of, containing the same amounts of sugar, salt, fat, fiber, macronutrients, carbohydrates and calories. Both groups of volunteers were allowed to eat as much as they wanted. After they finished a meal, their leftovers were carried down a couple floors and delivered to a team of nutritionists in a laboratory, who precisely weighed and characterized everything left on the plate.

Hall, it turns out, had it all wrong—processing, in fact, made all the difference. The subjects in Hall's study who subsisted on Cheerios and Chef Boyardee gained one pound per week on average and consumed in excess of 500 calories a day more than the group with the healthier diet. What's more, when they later switched to a natural diet, they dropped the extra weight. The conclusion: whatever food company chemists are doing to food, it makes people fatter.

The results opened up a new avenue of inquiry for Hall and his colleagues. What was it about the ultra-processed food that prompted this overindulgence and weight gain? The question is a matter of intense speculation and debate in the world of nutrition science—a debate that can only be solved with more research. What's clear, however, is that the ultra-processed foods favored by a vast proportion of Americans are causing harm.

The Two-Year Cupcake

Humans have been modifying food since hunter-gathers discovered fire and figured out how to barbeque stone-age animals. Ten thousand years ago, ancient Mesopotamians and Egyptians learned how to smoke, salt and dry their food to preserve it. In the 19th century, pasteurization and canning techniques vastly expanded the capacity for long-term storage and transport of food.

Processed food, as we know it today, arrived in the first half of the 20th century. That's when food engineers figured out how to use modified potato starch to form pork, ham, sugar, water and sodium nitrate into a pliable gelatinous blob that would fit into a rectangular tin emblazoned with the word "Spam." Two World Wars, the Space Race and increasing consumer demand for fast meals with a long shelf life that could support the lifestyle of the expanding middle class financed the scientific efforts necessary to give us spray drying, evaporation, freeze-drying and a sophisticated understanding of how to make a decent tasting cupcake you can put on a shelf and still eat two years later. By the early 2000s, Americans were getting more than half of their calories from chicken nuggets, artificially sweetened canned food, potato chips and other man-made concoctions.

Nutritionists didn't create a language to describe this trend until 2009. That year, Carlos A. Monteiro, a lanky, curly-haired professor of nutrition at the University of Sao Paulo, introduced the "NOVA Food Classification system," a novel grouping of foods based not on their nutritional content but according to the extent and purpose of the physical, biological and chemical processes applied to them after they were separated from nature.

He coined the term "ultra-processed," (as opposed to "minimally processed" or simply "processed") to refer to "industrial formulations made entirely or mostly from substances extracted from foods (oils, fats, sugar, starch and proteins), derived from food constituents (hydrogenated fats and modified starch), or synthesized in laboratories from food substrates or other organic sources (such as flavor enhancers, colors and food additives used to make the product hyper-palatable). Monteira excluded foods that had been exposed to simple processes like drying, fermentation, pasteurization or other processes that might subtract part of the food (frozen vegetables, dried pasta or eggs). He also carved out exceptions for products manufactured by industry with the use of salt, sugar, oil or other substances added to natural or minimally processed foods to preserve or to make them more palatable, but that could still be recognized as versions of the original foods—usually foods that had just two or three ingredients (such as beef jerky, or freshly made bread).

Ultra-processed food, by contrast, was meant to include Frankenstein-like creations that were often made up of added sugar, salt, fat and starches extracted from natural occurring foods and then blended with artificial colors, flavors and stabilizers to hold it all together. Soft drinks, hot dogs, cold cuts, packaged cookies and salty snacks like pretzel rods all qualified, as did many frozen dinners and canned entrees.

"They are not food," Monteiro says. "They are formulations. They contain chemical compounds that do not belong to food—that should not belong to foods."

Many researchers dismiss Monteiro's classification system as overly broad. The category of "ultra-processed foods," after all, encompasses a wide variety of different products with endlessly varied nutritional profiles. It lumps Twinkies, Doritos and diet soda together with protein-rich entrees like Perdue Chicken tenders, which are made from the rib meat of an actual chicken and then combined with dextrose, sugar, guar gum, yellow corn flour and other ingredients, and Hormel Beef and bean chili, made from actual beef, beans and crushed tomatoes and combined with less than 2 percent modified cornstarch, soy flour and caramel color.

Nonetheless, by defining a new category that represents levels of processing, he gave public health experts and epidemiologists the language to discuss how industrial chemists had changed food—and how to measure their inventions against a wide array of health problems. The strength of those associations soon began to generate attention.

Toxic Sugar

Although scientists haven't figured out how ultra-processed foods cause people to gain weight—which of the thousands of chemicals, additives, nutrients actually lead to worse health outcomes—the market forces that have guided food manufacturers are clear enough. Between 1980 and 2000, the period in which obesity and metabolic diseases began to rocket upwards, the number of calories available for purchase in the U.S. food supply increased 20 percent, from about 3,200 per person per day to 4,000, which dramatically increased competition for the limited attention and stomach capacity of the American consumer.

Nestle, the author of many books on the politics of food policy, suggests that federal farm subsidies that ensured surplus crops, such as corn, made it to market, along with the widespread adoption of cheap additives in the 1970s like high fructose corn syrup, were among the factors that drove this overproduction. Meanwhile in the 1980s, activist stockholders stepped up pressure on food companies to grow their quarterly growth profits to keep the stock prices rising. All of this fueled a high-stakes arms race in the food industry between competing product development and marketing teams.

"If you're trying to sell your food product and make a profit in an environment in which there's twice as many calories as anybody needs," says Nestle, "you either have to get people to buy yours instead of somebody else's or to get everybody to eat more in general."

To sell more, food companies made their products ubiquitous. They sold them in bookstores and libraries. They set up in clothing stores, drugstores and gas stations. They offered up bigger portions and created more cartoon characters to sell cereal, using tactics pioneered and perfected by Big Tobacco, which by then had begun to diversify from cigarettes into food. They also called in scientists, who helped devise ingenious marketing techniques and scientific innovations to sell more food.

Michael Moss devotes a chapter of his 2013 book Salt Sugar Fat to the exploits of Howard Moskowitz, an industry star who pioneered the use of advanced mathematics and computational science to "optimize" food products so that they created the most powerful cravings. Over the years, Moskowitz reengineered a wide array of products, ranging from General Mills breakfast cereals to Prego Spaghetti sauce, by testing out modifications in color, smell, packaging, taste and texture on human guinea pigs, and then feeding the data into a sophisticated mathematical model that "maps out the ingredients to the sensory perceptions these ingredients create, so that I can just dial up the product," Moskowitz explained to Moss.

The most important weapon in Big Food's arsenal turns out to be sugar. Moskowitz coined the term "bliss point" to describe the "perfect amount" of the sweetness in a product to maximize consumption. By focusing on the bliss point, Moss argues, food companies have changed the American palate in ways that predispose us to overeating the bad stuff (potato chips and ice cream) and pushing the good stuff (broccoli and asparagus) to the side. Recent studies, he says, show that 66 percent of the food in grocery stores now contain added sweeteners.

"These companies have learned how to find and exploit our basic instincts that attract us to food," says Moss, whose latest book, Hooked, examines the addictiveness of the food. "The problem isn't that these companies have engineered the perfect amount of sweetness for things like soda, cookies or ice cream. It's that they've marched around the grocery store, adding sugar to stuff that didn't used to be sweet, like bread and yogurts and spaghetti sauce. This has created this expectancy that everything should be sweet."

Fructose, one of the most commonly used sweeteners, is now present in many foods at concentrations unheard of in nature, according Robert Lustig, a pediatric endocrinologist affiliated with UC San Francisco and author of Metabolical, about the dangers of processed food. In recent years, studies have shown that fructose destroys or inactivates several key enzymes needed for the healthy functioning of mitochondria, the power plants in human cells that convert simple sugars into ATP, the form of energy we use to carry out the functions of the human body and brain.

This disruption in energy conversion causes a backlog of unprocessed glucose to circulate in the bloodstream. Sensing the excess glucose, the pancreas floods the system with the hormone insulin, which tells the body to remove the glucose from the bloodstream and store it as fat. Some of this fat tends to build up on the liver, which the body relies upon to filter, process and balance the blood leaving the stomach. The liver becomes sick and the problem worsens. Starved of the energy our mitochondria would normally provide, we eat more.

"It shouldn't be surprising that kids are getting type-two diabetes and fatty-liver disease that used to be the diseases of alcohol," he says. "We now know that fructose is a mitochondrial toxin, which turns into fat in the liver and is metabolized by the liver in ways virtually identical to how alcohol is metabolized."

Sugar isn't even the worst problem in the American diet. More damaging still is the consumption of processed grains, used in corn flakes, white bread and many other products. These grains are stripped of their outer shell, known as the "bran," and their inner germ, which contains fiber, fatty acids and nutrients, leaving only the carbohydrates. The human body digests these liberated carbohydrates much faster than when they're locked inside the grains.

"Instead of sitting in the stomach and gradually being broken down into glucose, it begins to break down as soon as it gets to your mouth and is almost fully digested by the time it has moved through the stomach, and all absorbed by the time it gets to your small bowel," says Dr. Dariush Mozaffarian, a cardiologist and dean of the nutrition department at Tufts University.

This rapid digestion starves the gut bacteria, which we rely on for healthy functioning of the digestive system, leading to increased gut permeability that in turn may allow bacteria and toxins to enter the bloodstream and cause widespread inflammation, a factor in a wide variety of diseases such as celiac disease, diabetes, asthma, Alzheimer's and cancer.

It also floods the bloodstream with glucose, causing insulin levels to spike. This high "glycemic load," a measure of how quickly blood sugar rises, can have long-term consequences for the way the body processes food, leading to a long-term dysregulation of the hormonal systems. These hormones tell the body to store more fat at the expense of providing calories to keep things running. The body, starved of energy, craves food—meaning we are forever hungry, even when we overeat.

"Having seen thousands of patients with obesity, I think people can show a lot of discipline around food choice and selection if they experience benefits," says David Ludwig, a pediatric endocrinologist at Boston Children's Hospital and a professor of Pediatrics at Harvard Medical School and of Nutrition at Harvard School of Public Health. "I think what we have trouble with consistently is resisting extreme hunger."

As Addictive as Heroin

Some researchers suggest the change in our diet may also be changing our brains, rewiring them with aberrant patterns that lead to compulsive eating, and possibly even addiction.

Nora Volkow, a neuroscientist who is now Director of the National Institute on Drug Abuse (NIDA) at the NIH, was one of the first to begin researching food addiction in 1980s. She was struck by similarities between the compulsive behaviors and experiences reported by drug addicts and alcoholics and those reported by obese patients who claimed to be unable to control their eating. In recent years, she says, evidence has emerged from her lab and others linking the pathological brain activation patterns seen in drug addicts to those seen in many obese research subjects and compulsive overeaters.

"When I first started to speak about it, there was a complete and absolute rejection, almost anger, from people who insisted it was an endocrinological disease, not a disease of addiction," she says. "But that's an artificial distinction. If you look at it from the outside, what is the difference between nicotine and an ultra-processed food if both have been designed optimally to generate that compulsive response—a response that manipulates the dopaminergic system in a way that you don't find in natural foods?"

Nicole Avena began studying whether or not sugar could actually meet the scientific criteria for other addictive substances in the early 2000s after hearing from recovering drug addicts that they found it more difficult to quit sugar than heroin. Avena, an associate professor of neuroscience at Mount Sinai School of Medicine, found that sugar, in both animals and humans, led to binging, withdrawal and craving—all components of addiction typically seen in drugs of abuse. She also saw neurochemical and neuroimaging changes in the brain virtually identical to those found in drug addicts. Sugar, when combined with other ingredients present in ultra-processed food, was more addictive still. In rats, sugar was found to be as addictive as cocaine.

"Our brains just aren't designed to be able to process these different types of ingredients in the quantities that we're being exposed to," says Avena.

Ultra-processed foods have something else in common with nicotine: Some of the biggest producers of processed foods were, from the 1980s to the end of the 2000s, known as Big Tobacco. In 1985, RJ Reynolds acquired Nabisco for $4.9 billion, and Phillip Morris acquired General Foods in a $5.75 billion deal that was then the largest takeover in U.S. history outside of the oil industry. Phillip Morris added Kraft to its portfolio in 1988 and rebranded itself as Altria in 2003. (RJR flipped Nabisco to Phillip Morris in 2000, which in turn spun off Kraft from its international tobacco business in 2007.)

UM's Gearhardt has been studying the events that led up the groundbreaking 1988 Surgeon General's report that deemed nicotine addictive, and the benchmarks used to do so, despite a concerted effort by one of the most powerful lobbies in the nation to prevent it.

One of the most important factors producing an addiction is the speed with which a drug hits the body and lights up the reward centers of the brain. By the time Big Tobacco began acquiring food companies, they had decades of experience studying and optimizing the speed with which their products delivered nicotine to the brain. They continued to harness that science in their food products.

"Many of these ultra-processed foods are almost pre-chewed for us," she says. "They melt in your mouth immediately. There's no protein, there's no water, there's no fiber slowing them down. It's going to hit your taste buds and light up your reward and motivation centers of the brain immediately. Then there's a secondary hit of dopamine when it gets absorbed into the body."

Taking on Big Food

The threat is so grave that policymakers have recently shown glimmers of a newfound willingness to take on the food industry. A report by the General Accounting Office in August, commissioned by members of Congress on the powerful House appropriations committee to review diet-related chronic health conditions and federal efforts to address them, painted a grim picture.

More than 30 percent of young people aged 17 to 24 no longer qualify for U.S. military service because of their weight. Diet-related ailments such as cardiovascular disease, cancer and diabetes soaked up 54 percent of the U.S. government's $383.6 billion in health care spending, which includes Medicare and Medicaid, in 2018. They accounted for about one-quarter of the nation's total $1.5 trillion in health care spending in 2018 and were associated with 1,487,411 deaths—more than half of deaths from all causes.

Recently policymakers on both sides of the aisle called for a White House conference along the lines of the 1969 conference on food, nutrition and health. That meeting, called by then-President Richard Nixon to address the hunger crisis, resulted in the creation of the special supplemental nutrition program for Woman, Infants and children (SNAP) and the school lunch program, among other things.

"Now we face a second food crisis," said Senator Cory Booker, who chaired a farm subcommittee earlier this month that focused on the GAO report. "Despite being the wealthiest nation in the world, we have created a food system that relentlessly encourages the overeating of empty calories that are literally making us sick and causing us to spend an ever-increasing amount of taxpayer dollars—literally, trillions of dollars a year—on health care costs to treat diet related diseases."

Nobody is under any illusions that solutions will come easy. In recent years, public health officials have launched major campaigns to deal with what many consider to be the lowest hanging fruit: regulations to reduce soda consumption through taxes and limitations on how federal and state food assistance can be spent, among other measures. The food industry, which has poured tens of millions of dollars into lobbying, campaign contributions and influencing public opinion, has fought back ferociously.

In California, where four cities have passed soda taxes, the beverage industry spent $7 million promoting a 2018 ballot initiative that would have made it harder for cities to raise taxes of any kind. The industry dropped the initiative after lawmakers agreed to implement a 12-year moratorium on local taxes on sugar-sweetened drinks. The word "ultra-processed foods" appears in U.S. dietary guidelines only in the references, says NYU's Nestle, because if it appeared more prominently "the food industry would go berserk." She notes that in 2015, when a scientific committee recommended changing guidelines to encourage Americans to eat less meat for reasons of "health and sustainability," industry lobbyists convinced Congress to insert language into a spending bill ordering the Department of Agriculture to change it.

"We could put restrictions on portion size, put restrictions on advertising and marketing, change federal subsidy policies to subsidize healthier foods and make them more available," Nestle says. "There's a whole lot of things we could do. But you can't do anything without taking on the food industry. And nobody wants to do that because they're very powerful—everybody eats and loves their products. Anytime anybody talks about taking on the food industry, all of a sudden we have charges of 'nanny statism.'"

(In response to a request for an interview, a spokeswoman for the Consumer Brands Association, which represents companies that manufacture food, beverages, household and personal care products, suggested Newsweek reach out to the SNAC International, formerly the Snack Food Association, which did not respond to inquiries.)

Congress has been slow to address the obesity crisis. Dr. Fatima Cody Stanford, an obesity medicine physician at Massachusetts General Hospital and Harvard Medical School, has been among those advocating for the passage of a bipartisan bill that would require Medicare to cover medications, behavioral therapy, dietician visits and other approved therapies to treat obesity. The bill has been introduced in both the House and Senate every year since 2013, but Congress has not passed it.

It will take time, research and public pressure to change minds in Washington, advocates say. For now, the best hope for a solution is to catalyze a groundswell of consumer demand for products that are healthier. Many food companies have recognized that diet-friendly, healthy choices are in demand and can move products. Which brings us back to the science.

To change minds, scientists—and the food industry itself—will need a better understanding of precisely what it is about the nation's diet that is feeding the public health crisis. "We need to better understand what the mechanisms are that are driving the deleterious effects of ultra-processed food so we can target policies and potential reformulations to improve the health of the nation."

"We need a national nutrition moonshot," says Tufts Mozaffarian. "We're drowning under an epidemic of diet-related disease."

Hall, for one, plans to run another comparison study to make sure people aren't simply eating more because the food tastes better. This time he'll make sure the processed and unprocessed dishes both taste equally delicious, as judged by independent tasters. The results will hopefully bring us another step closer to understanding and, eventually, action.