What Are Ultra-Processed Foods? A Detailed Scientific Guide

You can’t go on social media or read the news these days without seeing yet another warning about how ultra-processed foods are going to kill you.

This might sound hyperbolic, but there’s actually lots of research linking some ultra-processed foods to numerous health problems, including all-cause mortality. The trouble with these claims isn’t the lack of data behind them — it's that it can be really hard to tell when these foods are on your plate.

“It's been known for a long time that consuming ultra-processed foods on a regular basis increases the risk of several chronic diseases including cardiovascular disease, certain cancers, obesity, and type 2 diabetes,” says Samantha Heller, RDN, a clinical nutritionist at NYU Langone Health in New York City.

But how can you figure out which foods are ultra-processed and best to avoid, and which are not? This guide can help.

Under the Nova system, there are four categories of food:

• Group 1: Unprocessed and Minimally Processed Foods These are natural foods that come directly from plants or animals and also fungi, algae, and water, or natural foods that have been lightly processed to clean or remove some unwanted or inedible parts, but don’t include any added ingredients like oil, sugar, salt, or fat.

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• Group 2: Processed Culinary Ingredients These are substances derived from group 1 foods or from nature by processes such as pressing, refining, grinding, milling, and drying. These foods are rarely if ever consumed by themselves, but instead used in combination with other foods. Examples include oils, butter, lard, sugar, and salt.

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• Group 3: Processed Foods These are foods that are processed with the addition of salt, oil, sugar, or other substances from group 2 — but are derived from natural or minimally processed foods in group 1 and recognizable as these foods.

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  Examples include canned or bottled vegetables or legumes preserved in brine; whole fruit preserved in syrup; tinned fish preserved in oil; some types of processed animal foods such as ham, bacon, pastrami, and smoked fish; most freshly baked breads; and cheeses with added salt.
• Group 4: Ultra-Processed Foods These foods are formulations of ingredients typically created by industrial techniques and processes. Sugar, oils and fats, and salt are often used, as are food substances of no or rare culinary use, or additives to enhance taste.

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   Examples include carbonated soft drinks; many packaged snacks; candy; mass-produced packaged breads; cookies, pastries, cakes, and cake mixes; margarine and other spreads; sweetened breakfast “cereals”; fruit yogurt; “energy” drinks; preprepared meat, cheese, pasta, and pizza dishes; poultry and fish “nuggets” and “sticks”; sausages, burgers, and hot dogs; and ice cream.

Flaws With the Nova Classification System

Another limitation noted in many studies is that systems like Nova for defining ultra-processed foods are based on how foods are manufactured rather than what nutrients they might contain.

“The category of ultra-processed is related to poor health, but it’s a very broad category,” says Dariush Mozaffarian, MD, DrPH, director of the Food is Medicine Institute at the Friedman School of Nutrition Science and Policy at Tufts University in Boston.

“A breakfast cereal with tons of whole grains and honey is ultra-processed but so is one with tons of sugar,” Dr. Mozaffarian says.

For years, countless studies have linked ultra-processed foods to an increased risk of various health problems, including obesity, type 2 diabetes, heart disease, cancer, dementia, and a shorter lifespan.

“The health risks of these foods are likely related to the specific processes of how these foods are made, the ingredients they contain, and the displacement of healthier unprocessed or minimally processed foods,” says Andrea J. Glenn, RD, PhD, assistant professor in the department of nutrition and food studies at New York University in New York City.

Research links consuming ultra-processed foods with:

• Type 2 Diabetes One study that included participants from three large U.S. cohorts found that total ultra-processed food consumption is associated with higher type 2 diabetes risk. However, some subgroups of ultra-processed foods were associated with lower risk, such as ultra-processed cereals and ultra-processed dark breads and whole-grain breads.

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• Heart Disease One study found each additional serving of ultra-processed foods was associated with a 9 percent higher risk of dying from cardiovascular disease.

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  A more recent systematic review and meta-analysis found that higher total ultra-processed food intake was adversely associated with higher risk of cardiovascular disease (CVD) and coronary heart disease (CHD). Specifically, sugar-sweetened beverages, processed meats, and artificially-sweetened beverages were associated with higher CVD and CHD risk, but ultra-processed savory snacks, cold cereals, and yogurt- or dairy-based desserts were inversely associated with CVD and CHD risk. Ultra-processed bread and cold cereals were also associated with lower stroke risk.

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• Cancer A systematic review and meta-analysis found a consistent significant association between intake of ultra-processed foods and the risk of overall and several cancers, including colorectal, breast, and pancreatic cancer.

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  Another large, multinational cohort study found that higher ultra-processed food consumption was associated with an increased risk of multimorbidity of cancer and cardiometabolic diseases, and animal-based products and sugar-sweetened beverages were especially harmful. Ultra-processed breads and cereals were not associated with higher risk of these diseases.

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• Dementia A study with more than 70,000 adults 55 and older found each 10 percent increase in ultra-processed food consumption associated with a 25 percent higher risk of dementia and a 14 percent higher risk of Alzheimer’s disease.

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• All-Cause Mortality A large population-based cohort study found that a higher intake of ultra-processed foods was associated with slightly higher all-cause mortality, with meat/poultry/seafood-based ready-to-eat products showing particularly strong associations with mortality.

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• Weight Gain If you’re trying to lose weight, you may also want to avoid ultra-processed foods. In a small clinical trial, 20 people who were given ultra-processed foods consumed about 500 calories more each day. Over two weeks, people eating ultra-processed foods gained about 2 pounds, while those eating unprocessed foods lost about 2 pounds.

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  Another small, short-term study found that consumption of ultra-processed foods causes significant weight gain.

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It’s not hard to tell the difference between an unprocessed ear of corn and an ultra-processed bag of corn chips. But it can be challenging to determine how much processing goes into foods that come boxed, bagged, canned, or frozen.

“Food manufacturers are not required to label if food is ultra-processed, and anything boxed, canned, or frozen does not automatically mean they are ultra-processed,” says Dr. Glenn. “Some foods that people may assume are ultra-processed foods are not actually ultra-processed foods — like canned or frozen fruits and vegetables,” she adds.

• Canned corn (processed) versus corn chips (ultra-processed)
• Apple juice (processed) versus apple pie (ultra-processed)
• Baked potato (processed) versus french fries (ultra-processed)
• Flour (processed) versus cookies (ultra-processed)

Focusing on these items is a good, if imperfect, way to identify ultra-processed foods, Glenn says.

“Consumers can examine the label and check out the ingredient list to get a sense if a product is ultra-processed or not,” Glenn says. “Ingredients are listed by weight in the ingredient list, so if you see a lot of ingredients you typically would not use in the kitchen at the beginning of the list then the food is considered ultra-processed.”

Ingredients Commonly Used in Ultra-Processed Foods

• Isolates (specifically, sources of protein such as hydrolyzed proteins, soy protein isolate, gluten, casein, whey protein, and “mechanically separated meat”)
• High-fructose corn syrup, as well as other varieties of sugars including fructose, “fruit juice concentrates,” invert sugar, maltodextrin, dextrose, and lactose
• Hydrogenated oils and interesterified oils
• Additives on the label like colors and sweeteners

Beyond this, Mozaffarian says there are some other things to look for on labels and try to avoid:

• Refined Sugar and Starch Use a 10:1 rule when you look at how much carbohydrates and fiber you see on the label. You want to have at least 1 gram of fiber for every 10 grams of carbohydrates.
• Sodium Choose products with the lowest amount of sodium on the label.
• Saturated Fat Total fat listed on the label should be much bigger than the amount of saturated fat. This means you’re getting products made with healthier fats.
• Shelf Life Before you pick up a food product, check the expiration date — it shouldn’t be too far away. Products that don’t expire for many months, or longer, have to be heavily processed to extend their shelf life.

Healthy Ultra-Processed Foods

As for items within the ulta-processed category as per Nova, ideally people want to minimize these as much as possible, but some of these foods may be healthier than others, says Glenn.

“For example, some soy milk products would be considered ultra-processed, or foods like breakfast cereals or fruit yogurts, where in research studies the data looks okay so far, although I would love to continue to see more research on this topic and on these specific products,” she says.

Sometimes, avoiding ultra-processed foods is easier said than done. Cost and convenience are big factors, Glenn says. Unprocessed foods may be unavailable, or unaffordable, for many shoppers.

And looking for foods that are labeled as organic, all-natural, or plant-based won’t necessarily help you avoid ultra-processed products, Mozaffarian notes.

Here are some ways you may still get healthier alternatives to ultra-processed foods:

• Buy processed foods with less sugar, salt, and fat. This will help you avoid some ingredients that are responsible for health problems, Mozaffarian says.
• Get processed foods with better ingredients. Think whole-grain pasta or shredded wheat cereal instead of “regular” refined grain pasta or sugary cereals that look like dessert, Heller says.
• Stock up on healthier staples. Keep on hand products like low- or no-sodium canned or dried beans; whole grains like oatmeal, quinoa, or brown rice; low- or no-sugar and low- or no-sodium peanut butter or almond butter; trail mix without candy (in moderation), and frozen fruits and vegetables, Heller says. This can make it easier to quickly throw together a healthier meal.
• Cook more meals at home. Preparing your own meals from whole foods lets you control the amount of added sugars, fats, and salts, Heller says.
• Make your own snacks. Instead of buying things like sugary trail mix or granola bars, take control of the ingredients list yourself by combining things like dried fruits and nuts with whole grains, instead of getting the prepackaged versions of snacks, Glenn says.

• For optimal health, try to limit or avoid ultra-processed foods, which are associated with numerous health problems.
• Pay attention to food labels and, when possible, opt for whole, fresh foods without labels at all.
• If you currently consume ultra-processed foods, keep in mind that you don’t need to overhaul your diet all at once.
• Making different choices a little bit at a time can add up to meaningful reductions in consumption of ultra-processed foods. For instance, getting a pizza topped with veggies instead of sausage, or a falafel sandwich with tomato and cucumber instead of a ham and Swiss on rye are both good ways to avoid some ultra-processed products.