Ultra-Processed Foods and the NOVA Scale

"Ultra-processed food" has become one of the most talked-about ideas in nutrition. The term comes from the NOVA classification system, which sorts foods by how much and why they've been processed rather than by their nutrients. This guide explains the four NOVA groups, what the research shows, where critics push back, and how to use the idea when you shop.

What the NOVA scale is

NOVA was developed by researchers led by Carlos Monteiro at the University of São Paulo in Brazil. It places every food into one of four groups:

Group 1: Unprocessed or minimally processed foods

Fresh, frozen, dried, or pasteurized foods without added ingredients, such as fruits, vegetables, eggs, milk, plain meat and fish, dried beans, rice, oats, and plain nuts.

Group 2: Processed culinary ingredients

Ingredients made from Group 1 foods and used in cooking, such as oils, butter, sugar, salt, and flour.

Group 3: Processed foods

Group 1 foods with Group 2 ingredients added, usually with a few recognizable ingredients. Examples include canned vegetables in brine, simple cheeses, fresh-baked bread made from flour, water, yeast, and salt, and canned fish.

Group 4: Ultra-processed foods

Industrial formulations made mostly from substances extracted or derived from foods, often with additives rarely used in home kitchens. Signs include ingredients like high-fructose corn syrup, hydrolyzed protein, protein isolates, maltodextrin, modified starch, emulsifiers, flavor enhancers, and artificial colors or flavors. Examples include soft drinks, packaged snack cakes, many breakfast cereals, flavored chips, instant noodles, hot dogs, and many frozen ready meals.

How much of the US diet is ultra-processed

Studies using national survey data from the CDC's National Health and Nutrition Examination Survey (NHANES) estimate that ultra-processed foods make up more than half of the calories Americans eat, with even higher shares among children and teens. In July 2025, the FDA and USDA issued a request for information on a federal definition of ultra-processed foods, with comments closing in October 2025. In August 2026, the agencies submitted a proposed definition to the White House Office of Management and Budget for review. That proposal has not been finalized and, on its own, creates no labeling requirement.

What the research shows

Observational studies

Many large studies that follow people over time have linked higher intake of ultra-processed foods with higher risk of obesity, type 2 diabetes, cardiovascular disease, depression, and early death. A 2024 umbrella review in The BMJ pulled together dozens of meta-analyses and found associations with 32 health outcomes. It rated the evidence as convincing for a few outcomes, such as cardiovascular disease death and type 2 diabetes, and weaker for many others.

The NIH feeding trial

The best-known controlled experiment was run at the National Institutes of Health and published in 2019. Twenty adults lived in a research center for four weeks. For two weeks they ate an ultra-processed diet, and for two weeks a minimally processed diet. Both diets offered the same calories, sugar, fat, fiber, and sodium, and people could eat as much as they wanted. On the ultra-processed diet, participants ate about 500 more calories a day and gained weight; on the minimally processed diet, they lost weight.

The study was small and short, but it suggested that something about ultra-processed foods, such as how fast they're eaten, how soft or calorie-dense they are, or how they're flavored, may lead people to eat more.

Limits and criticisms

NOVA is useful, but it has real weaknesses, and it's fair to be clear about them:

• Observational studies can't prove cause and effect. People who eat a lot of ultra-processed food may differ in income, sleep, stress, and activity in ways studies can't fully account for.
• The group is very broad. Group 4 puts soda and candy in the same category as some whole-grain breads, flavored yogurts, and plant-based milks, which have very different nutrient profiles.
• Classification can be subjective. Studies have found that experts don't always agree on which NOVA group a food belongs in.
• It's not clear which part matters. The health effects could come from high levels of sugar, sodium, and refined starch, from low fiber, from specific additives, or from how the foods are engineered. Researchers are still sorting this out.

The current Dietary Guidelines for Americans 2025–2030 are the first edition to call out highly processed foods directly. They advise limiting highly processed packaged, prepared, and ready-to-eat foods that are salty or sweet, such as chips, cookies, and candy, and prioritizing nutrient-dense foods and home-prepared meals. They don't adopt the NOVA system itself, and the 2020–2025 edition didn't address processing at all, focusing instead on added sugars, saturated fat, and sodium.

How to spot ultra-processed foods

• Read the ingredients list. Long lists with ingredients you wouldn't find in a home kitchen, like maltodextrin, soy protein isolate, or mono- and diglycerides, are a common sign.
• Look for cosmetic additives. Colors, flavor enhancers, emulsifiers, and non-sugar sweeteners are typical of Group 4.
• Check the nutrients too. Processing level and nutrition quality overlap but aren't the same. A food can be minimally processed and still high in sodium, like some cheeses.

A practical approach

You don't need to avoid every ultra-processed food. Canned beans, frozen vegetables, whole-grain bread, and plain yogurt are processed foods that can be part of a healthy diet, and some ultra-processed products are convenient and affordable. A realistic goal is to shift the balance: build meals around Group 1 foods, use Group 2 ingredients to cook them, and treat heavily processed snacks, sweets, and sugary drinks as occasional foods.

How to use this on myfoodfact.com

• See which products have the longest additive lists in products with the most additives.
• Look up unfamiliar ingredients like maltodextrin or modified starch in the ingredient directory.
• Read about specific ultra-processed ingredients in our guides to high-fructose corn syrup and synthetic food dyes.

The bottom line

The NOVA scale sorts food by processing, and research consistently links diets high in ultra-processed foods with worse health outcomes. Most of that evidence is observational, the category is broad, and scientists are still working out why the link exists. Reading the ingredients list alongside the Nutrition Facts label gives you a fuller picture than either one alone.

This guide is for general information and is not medical advice. Talk with your doctor or a registered dietitian before making major changes to your diet.