Ultra-processed foods are industrially manufactured products that contain ingredients you’d rarely or never use in a home kitchen, things like emulsifiers, hydrolyzed proteins, high fructose corn syrup, and artificial flavors. In the United States, they account for 55% of all calories consumed by people age one and older, according to CDC data from 2021 to 2023. That number is even higher for kids ages 6 to 11, who get nearly 65% of their daily calories from these products.
The term comes from a classification system developed by nutrition researchers, and it has reshaped how scientists study diet and disease. But it’s also more nuanced than it first appears. Some ultra-processed foods are nutritional wastelands, while others (like fortified soy milk or whole grain bread) can be genuinely good for you.
How the NOVA System Classifies Food
The most widely used framework for defining ultra-processed food is the NOVA classification, which sorts everything you eat into four groups based on the type and extent of processing involved.
- Group 1: Unprocessed or minimally processed foods. Fresh fruits, vegetables, eggs, plain meat, nuts, and grains that have been dried, ground, or pasteurized but not fundamentally altered.
- Group 2: Processed culinary ingredients. Oils, butter, sugar, salt, and flour. These are extracted from Group 1 foods and used in cooking, but rarely eaten on their own.
- Group 3: Processed foods. Products made by combining Groups 1 and 2 in simple ways: canned vegetables in brine, freshly baked bread with a short ingredient list, cheese, smoked fish.
- Group 4: Ultra-processed foods. Industrial formulations typically containing five or more ingredients, including substances not found in home kitchens: emulsifiers, thickeners, flavor enhancers, colorings, sweeteners, and preservatives designed to imitate or enhance the qualities of real food.
The classification isn’t strictly about how much processing a food undergoes. It’s more about what ends up in the final product and whether industrial additives play a central role. That distinction matters because it means some foods that seem simple get flagged as ultra-processed. Most soy milks, for instance, land in Group 4 because they contain added sugars and emulsifiers, even when they’re made from whole soybeans.
Common Examples You Might Not Expect
The obvious ultra-processed foods are easy to spot: soft drinks, packaged snack cakes, instant noodles, chicken nuggets, candy. But the category also includes products that many people consider healthy or at least neutral. Prepackaged whole grain breads, many flavored yogurts, instant oatmeal, jarred pasta sauces, protein bars, and most breakfast cereals all qualify.
This is one of the biggest sources of confusion around ultra-processed foods. Baked beans contain protein, fiber, iron, and potassium, and bean consumption is linked to lower cholesterol and more stable blood sugar. Yet baked beans are technically ultra-processed. Dairy alternatives, meat substitutes, and fortified plant milks fall into the same category despite offering real nutritional benefits. The label “ultra-processed” doesn’t automatically mean a food is harmful. It means the food was made using industrial techniques and ingredients that go beyond basic cooking.
How to Spot Them on a Label
You won’t find “ultra-processed” printed on any package, so reading ingredient lists is the most reliable way to identify these foods. A few cues make the job easier.
Look at the length of the ingredient list first. Five or more ingredients is a common threshold. Then scan for substances you wouldn’t stock in your pantry: things like carboxymethylcellulose, polysorbate 80, hydrolyzed vegetable protein, or mono- and diglycerides. If you can’t picture buying it at a grocery store and adding it to a recipe, it’s a marker of ultra-processing.
The words “flavored” or “instant” on the front of the package are quick red flags. Check the first two ingredients for refined flour listed as “enriched flour,” “semolina,” “durum,” or just “wheat flour” without the word “whole.” And watch for multiple sweeteners scattered throughout the list. If you see cane sugar plus brown rice syrup plus something ending in “-ose,” the manufacturer may have split sugars across several names so that none of them appears as the first ingredient. The total sugar content could be higher than anything else in the product.
Why They Lead to Overeating
A landmark study conducted at the National Institutes of Health was the first to demonstrate a causal link between ultra-processed diets and weight gain. Researchers housed participants in a clinical facility for four weeks, feeding them either ultra-processed or minimally processed meals for two weeks each. Both diets were matched for calories, sugar, fat, fiber, and salt, and people could eat as much as they wanted. When participants ate the ultra-processed meals, they consumed significantly more calories and gained weight. When they switched to minimally processed meals, they ate less and lost weight.
The reasons aren’t fully settled, but several factors likely contribute. Ultra-processed foods are engineered for rapid consumption. They tend to be softer, easier to chew, and more calorie-dense per bite, which means you can eat more before your body registers fullness. They also combine salt, sugar, and fat in ratios that are uncommon in whole foods but highly rewarding to the brain.
Links to Chronic Disease
Large population studies consistently connect high ultra-processed food intake with increased risks of obesity, type 2 diabetes, cardiovascular disease, and colorectal cancer. A major cohort study published in The BMJ found that people who ate the most ultra-processed food (around 7.4 servings per day) had a 4% higher risk of death from any cause compared to those who ate the least (around 3 servings per day). That may sound modest, but it reflects a population-wide pattern after adjusting for other diet and lifestyle factors. Notably, the study found no specific link between ultra-processed food and death from cardiovascular disease, cancer, or respiratory disease individually, suggesting the relationship between these foods and health is complex and still being refined.
What They Do to Your Gut
One of the more concerning areas of research involves the emulsifiers commonly added to ultra-processed foods. These are the compounds that keep oil and water from separating, giving products a smooth, stable texture. In animal studies, two widely used emulsifiers (sodium carboxymethylcellulose and polysorbate 80) were shown to thin the protective mucus layer lining the intestine, making it easier for bacteria to reach the gut wall. This triggered low-grade inflammation and weight gain.
The mechanism appears to involve changes in bacterial behavior. Emulsifiers can increase how motile gut bacteria become, essentially making them more aggressive at penetrating the mucus barrier. Lab research has also shown that emulsifiers can damage bacterial cell membranes directly, reducing the viability of certain microbes in a dose-dependent way. The more emulsifier present, the greater the disruption. These findings come primarily from lab and animal models, so the exact effects in humans are still being studied, but the pattern is consistent enough to draw attention from public health researchers.
Who Eats the Most
CDC data collected between August 2021 and August 2023 paint a clear picture of how deeply ultra-processed foods are embedded in the American diet. Children and teenagers are the heaviest consumers. Kids ages 6 to 11 get 64.8% of their calories from ultra-processed sources, and teens ages 12 to 18 get 63%. Even the youngest group, children ages 1 to 5, are at 56.1%.
Among adults, consumption gradually declines with age but never drops below half. Adults ages 19 to 39 get 54.4% of their calories from ultra-processed foods, those 40 to 59 get 52.6%, and adults 60 and older get 51.7%. No age group in the U.S. currently gets less than half its calories from these products.
A Practical Way to Think About It
Brazil’s national dietary guidelines, often cited as a model for addressing ultra-processed food at the policy level, boil the advice down to four rules: make minimally processed foods the foundation of your diet, use oils, fats, salt, and sugar in small amounts for cooking, limit processed foods, and avoid ultra-processed foods.
In practice, avoiding all ultra-processed foods is unrealistic for most people, and the research suggests it’s not entirely necessary either. The goal is shifting the balance. When more than half your calories come from industrial formulations, as is currently the case for the average American, there’s meaningful room to swap in whole foods. Cooking with basic ingredients more often, choosing plain versions of dairy and grains over flavored ones, and reading ingredient lists with a critical eye are the most effective starting points. Not every ultra-processed food is equally problematic, and some, like fortified plant milks or canned beans, carry genuine nutritional value. The biggest gains come from cutting back on the products that offer very little beyond calories, salt, and sugar.