Ultra-processed food

Based on Wikipedia: Ultra-processed food

In 2019, a researcher at the National Institutes of Health did something unusual: he locked twenty people in a hospital ward for a month and fed them precisely controlled diets. Half ate ultra-processed foods; half ate meals prepared from scratch. Both diets had identical calories, sugar, fat, fiber, and sodium. The participants could eat as much as they wanted.

The results were striking. People eating ultra-processed food consumed about 500 extra calories per day and gained an average of two pounds in just two weeks. When they switched to the unprocessed diet, they lost weight at the same rate. Something about these industrial foods seemed to override the body's natural appetite regulation—and scientists are still trying to figure out exactly what.

What Makes Food "Ultra-Processed"?

The term sounds scientific, but it's surprisingly hard to pin down. Ultra-processed food isn't defined by a single ingredient or a specific chemical process. It's more of a category—a way of describing foods that have traveled so far from their original form that they've become something fundamentally different.

Think of it this way. A tomato is unprocessed. Canned tomatoes are processed. But that bright red squeeze bottle of ketchup containing high-fructose corn syrup, modified food starch, and a dozen other ingredients? That's ultra-processed.

The concept emerged from Brazil, where a nutrition researcher named Carlos Augusto Monteiro was trying to understand a puzzling trend. His country was getting fatter and sicker, but not because people were eating more traditional foods like rice and beans. Instead, they were consuming more packaged products that bore little resemblance to anything their grandparents would have recognized as food.

Monteiro drew inspiration from the American journalist Michael Pollan, whose 2006 book "The Omnivore's Dilemma" memorably described highly processed industrial food as "edible food-like substances." In 2009, Monteiro coined the term "ultra-processed food" and began developing a classification system called Nova—from the Portuguese word for "new."

The Nova System: A New Way of Looking at Food

Traditional nutrition science obsesses over nutrients: vitamins, minerals, fats, proteins, carbohydrates. The Nova system takes a radically different approach. It doesn't care whether your breakfast cereal is "fortified with 12 essential vitamins." It asks instead: how was this food made, and by whom?

Nova divides all food into four groups.

Group One contains unprocessed or minimally processed foods—fruits, vegetables, meat, eggs, milk. These are foods that look essentially like they did when they left the farm, perhaps cleaned, refrigerated, or pasteurized, but not fundamentally transformed.

Group Two consists of processed culinary ingredients: cooking oils, butter, sugar, salt, flour. These are substances extracted from Group One foods, meant to be used in home cooking rather than eaten alone.

Group Three includes processed foods—products made by combining Groups One and Two in relatively simple ways. Freshly baked bread. Canned vegetables. Cheese. Salted nuts. These foods have been around for centuries, preserving and enhancing natural ingredients.

Then there's Group Four: ultra-processed foods.

The Industrial Creations

Ultra-processed foods are industrial formulations. They're typically made from substances extracted from foods (oils, fats, sugar, starch, proteins) or synthesized in laboratories (flavor enhancers, colors, emulsifiers). The original food—if there was one—has been broken down and rebuilt into something engineered for maximum appeal and shelf life.

The ingredients list tells the story. If you see high-fructose corn syrup, hydrogenated oils, protein isolates, modified starches, or a parade of additives you can't pronounce, you're likely looking at an ultra-processed product.

Consider instant noodles. The wheat has been refined and processed into a dough, then deep-fried and dehydrated. The flavor packet contains monosodium glutamate (a flavor enhancer), maltodextrin (a carbohydrate used as a filler), artificial colors, and a dozen other additives. The final product bears almost no nutritional resemblance to the grain it came from.

The category is vast: soft drinks, packaged snacks, frozen pizza, hot dogs, chicken nuggets, instant soups, breakfast cereals, flavored yogurts, margarine, energy bars, infant formula. Most bread sold in supermarkets qualifies. So does most ice cream, most candy, most fast food.

The Scale of the Transformation

Ultra-processed foods barely existed before the twentieth century. Then came a cascade of innovations: chemical preservatives, industrial refrigeration, hydrogenation (which turns liquid oils into solid fats), high-fructose corn syrup, artificial sweeteners, flavor compounds, emulsifiers that make oil and water mix.

Early products now considered ultra-processed include Jell-O, launched in 1897, and Crisco, the hydrogenated vegetable shortening that hit shelves in 1911. Spam followed in 1937, Velveeta in 1928, Kraft Macaroni and Cheese in 1937, Oreos in 1912.

But these were novelties. The real transformation came after World War II.

The war had created a food science revolution out of necessity. Soldiers needed rations that could survive airdrops, sit in tropical heat for months, and still provide nutrition. Military researchers developed powdered cheeses, dehydrated potatoes, concentrated flavor compounds, and packaging that could withstand anything short of artillery fire.

After the war, these technologies found their way into the consumer market. Convenience became king. Frozen TV dinners appeared in the 1950s. Fast food chains multiplied. By the 1980s, ultra-processed foods had become the dominant form of eating in wealthy countries.

How Much Are We Eating?

The numbers are sobering.

In the United States, ultra-processed foods account for about 58 percent of all calories consumed. The United Kingdom is close behind at 57 percent. This means that for the average American or Briton, more than half of everything they eat comes from industrial formulations rather than recognizable food.

Other countries haven't gone quite as far. In Chile, France, Mexico, and Spain, ultra-processed foods make up 25 to 35 percent of calories. In Italy, Colombia, and Taiwan, the figure drops below 20 percent—partly because these countries have maintained stronger traditions of home cooking and fresh markets.

But nearly everywhere, the trend points upward. Ultra-processed food sales have risen consistently since the 1990s, spreading from wealthy nations into middle-income countries where multinational food companies see enormous growth potential.

Why These Foods Dominate

Ultra-processed foods have conquered the global diet for reasons that make perfect economic sense.

They're cheap to make. The ingredients—refined starches, vegetable oils, sugar, salt, and various additives—cost a fraction of whole foods. A bag of chips costs far less to produce than the equivalent calories in actual potatoes, partly because the chips can be made from the cheapest potato varieties, the cheapest oils, and ingredients that would never survive as whole foods.

They last forever. Or close to it. Preservatives and packaging give ultra-processed foods shelf lives measured in months or years, not days. This dramatically reduces waste and simplifies distribution. A frozen pizza can travel thousands of miles and sit in a warehouse for six months without spoiling.

They're engineered to taste good. Food scientists have spent decades perfecting what the industry calls "the bliss point"—the precise combination of sugar, salt, and fat that maximizes pleasure and keeps people coming back. Ultra-processed foods don't just satisfy hunger; they're designed to create cravings.

They're convenient. In a world where time is scarce and cooking skills are declining, ready-to-eat meals offer an irresistible bargain. Open a package, heat it up (maybe), and dinner is served.

The companies that make these products have another advantage: scale. Global food conglomerates can produce identical products in factories around the world, supported by massive advertising budgets and sophisticated data analytics that help them target consumers with remarkable precision.

The Health Question

Here's where things get complicated—and contentious.

The epidemiological evidence linking ultra-processed foods to poor health outcomes has grown steadily over the past decade. Study after study has found associations between high consumption of these foods and increased risks of obesity, type 2 diabetes, cardiovascular disease, depression, and certain cancers.

A major meta-analysis published in The BMJ in 2024 reviewed evidence from 32 studies and found that people who ate the most ultra-processed foods had significantly worse health outcomes than those who ate the least. Another 2024 analysis found a 17 percent increased risk of cardiovascular disease among high consumers. A 2025 review linked high ultra-processed food intake to a 15 percent increase in all-cause mortality—dying from anything.

The diabetes connection is particularly stark. A 2023 meta-analysis following more than 415,000 people found that each 10 percent increase in ultra-processed food consumption was associated with a 12 percent higher risk of developing type 2 diabetes.

Cancer risks appear elevated too. A 2023 review found higher rates of colorectal, breast, and pancreatic cancers among heavy consumers of ultra-processed foods.

But Why?

This is the billion-dollar question, and scientists don't have a definitive answer.

The obvious suspect is nutritional quality. Ultra-processed foods tend to be high in calories, sugar, salt, and unhealthy fats while being low in fiber, vitamins, and minerals. People who eat a lot of them are simply getting too many bad things and not enough good things.

But the controlled feeding study at the National Institutes of Health—where researchers matched the nutritional profiles of processed and unprocessed diets—suggests something more is going on. Even when the nutrients are identical, something about ultra-processed food makes people eat more of it.

Several theories try to explain this phenomenon.

One focuses on texture. Ultra-processed foods are often described as "pre-digested"—soft, easy to chew, quick to swallow. The body may not register these foods the same way it registers whole foods that require more mechanical processing. You can inhale a bag of chips; eating the same calories in baked potatoes takes considerably longer.

Another theory points to the "hyperpalatability" of these products—the carefully engineered combination of sugar, fat, and salt that activates reward centers in the brain. Some researchers have suggested that ultra-processed foods may trigger responses similar to addictive substances, though this remains controversial.

Then there are the additives. Emulsifiers, which help ingredients mix smoothly, may disrupt the gut microbiome—the community of bacteria that lives in our intestines and plays a crucial role in metabolism and immune function. Artificial sweeteners might confuse the body's appetite regulation systems. High-temperature processing creates chemical compounds that don't exist in nature.

The honest answer is that we don't know which of these factors matters most, or whether they all contribute to the problem.

The Critics Speak Up

Not everyone accepts the case against ultra-processed foods.

Some scientists argue that the Nova classification is too imprecise to be scientifically useful. Where exactly is the line between "processed" and "ultra-processed"? Is store-bought hummus ultra-processed because it contains added oil and preservatives? What about whole-grain breakfast cereals fortified with vitamins?

The definition relies partly on who makes the food and how it's marketed, not just its physical properties. This strikes some researchers as unscientific—you can't put "marketing" in a test tube.

Critics also point out that the category lumps together wildly different products. Soft drinks, with their sky-high sugar content, sit alongside fortified breads and infant formulas in Group Four. Studies that treat all ultra-processed foods as equivalent might be detecting the harms of soda while unfairly maligning breakfast cereal.

Indeed, when researchers break down the data by type of ultra-processed food, the results become more nuanced. Soft drinks and processed meats consistently show negative associations with health. But some ultra-processed foods, including certain breakfast cereals, actually show inverse associations—meaning people who eat them appear healthier than those who don't.

There's also the uncomfortable fact that for many people, ultra-processed foods are the most accessible and affordable options. Telling a single parent working two jobs to cook meals from scratch isn't just impractical; it may push them toward even less healthy choices. Food deserts—neighborhoods without grocery stores selling fresh produce—are a real phenomenon, and the people living in them often depend on packaged foods to survive.

The Missing Experiment

The gold standard in medical research is the randomized controlled trial: take two groups of people, give one group the treatment and the other a placebo, and see what happens. We have almost none of these for ultra-processed foods.

That single NIH study mentioned at the beginning of this essay is a rare exception, and it only measured weight gain over a few weeks. We don't have randomized trials looking at heart disease, cancer, or death—and for practical and ethical reasons, we probably never will. You can't lock thousands of people in a hospital ward for years and control everything they eat.

This means we're stuck with epidemiological studies, which can show associations but can't prove causation. People who eat lots of ultra-processed food might differ from people who don't in ways that researchers can't fully measure or control for. Maybe they exercise less, smoke more, have less access to healthcare, or face more chronic stress.

The associations are consistent enough that most researchers believe something real is going on. But the precise mechanism—the smoking gun—remains elusive.

What Should You Do?

Major health organizations have started weighing in. The World Health Organization and the American Heart Association both recommend reducing ultra-processed food consumption and eating more fruits, vegetables, whole grains, and lean proteins.

Some countries have gone further. Several Latin American nations now require warning labels on ultra-processed products. Chile's strict labeling requirements—black stop signs warning of high sugar, salt, or fat—have been credited with reducing consumption of the worst offenders.

The practical advice is simple, even if following it isn't always easy: cook more. Eat foods that look like foods. When you do buy packaged products, choose ones with short ingredient lists full of recognizable items. Limit soft drinks and processed meats, which have the strongest evidence of harm.

But individual choices only go so far. The food environment shapes what people eat far more than willpower or education. Real change probably requires policy interventions: taxes on the worst products, subsidies for healthier options, restrictions on marketing to children, investment in food access for underserved communities.

A Modern Paradox

We've created a food system of remarkable abundance. Calories are cheaper and more available than at any point in human history. Famines have become rare. The average person today has access to a variety of flavors and cuisines that would have been unimaginable to their great-grandparents.

And yet something has gone wrong.

Obesity has tripled worldwide since 1975. Type 2 diabetes, once called "adult-onset" because it was so rare in young people, now affects children. Heart disease remains the leading cause of death in most wealthy countries. The same industrial food system that ended scarcity may be creating new forms of malnutrition—not too few calories, but too few nutrients and too many of the wrong ingredients.

Ultra-processed foods sit at the center of this paradox. They represent an extraordinary achievement of human ingenuity: shelf-stable, convenient, affordable, delicious. They also represent something troubling: foods designed primarily to sell, not to nourish, engineered in laboratories to maximize consumption regardless of the consequences for human health.

The debate over what to do about them will only intensify as the evidence accumulates. For now, the safest bet is probably the oldest advice in nutrition: eat food, not too much, mostly plants. The tricky part is that in the modern supermarket, identifying what counts as "food" has become surprisingly difficult.