Ultra-Processed Foods: What They Are and Why They Matter
Not all processed food is a problem. Here's how to tell frozen peas from frozen pizza, and how much it matters.
The short version
- Processing exists on a spectrum, and things like frozen vegetables and canned beans are great.
- In a tightly controlled trial, people ate about 500 more calories a day on an ultra-processed diet.
- The 2025 to 2030 US Dietary Guidelines now tell Americans to avoid highly processed foods.
- You don't need perfection. Move your overall pattern in the right direction.
What counts as ultra-processed?
The most widely used system, called NOVA, sorts food into four groups:
| Group | What it means | Examples |
|---|---|---|
| 1. Unprocessed or minimally processed | Basically as nature made it | Fresh or frozen vegetables, fruit, eggs, plain meat, milk, oats |
| 2. Cooking ingredients | Extracted from foods | Olive oil, butter, salt, sugar |
| 3. Processed | Simple foods with a few additions | Canned beans, canned fish, cheese, fresh bread |
| 4. Ultra-processed | Industrial formulas, often with additives you wouldn't use at home | Soda, chips, packaged sweets, instant noodles, many ready meals, hot dogs, many breakfast cereals |
A quick home test: if the ingredient list has things you wouldn't find in a kitchen, such as emulsifiers, flavorings, color additives and modified starches, it's probably ultra-processed.
What the evidence says
The key trial. In 2019, NIH researcher Kevin Hall put 20 adults in a research ward for four weeks. For two weeks they got ultra-processed meals, and for two weeks they got minimally processed ones. The meals were matched for calories, sugar, fat, fiber and other nutrients, and people could eat as much as they wanted. They ate about 500 calories more a day on the ultra-processed diet, gaining about 2 pounds, and lost about 2 pounds on the other. They also ate faster. It was small and short, but it was unusually rigorous.
Population studies. Diets high in these foods are repeatedly linked to obesity, type 2 diabetes, heart disease and early death. These studies can't prove cause, and scientists don't yet agree on what's responsible. Likely candidates include how soft and fast to eat they are, how dense in calories they are, and how they're engineered to taste good.
Not all equal. Some ultra-processed foods don't look harmful, including some whole-grain breads, plain yogurts with additives and fortified cereals. Sugary drinks and processed meats have the strongest evidence against them.
How to eat less of it, realistically
These foods are cheap, quick and everywhere, and that's not a personal failing. Start with swaps that don't cost much effort:
| Instead of | Try |
|---|---|
| Sugary cereal | Oats with fruit |
| Flavored yogurt | Plain yogurt with berries |
| Chips | Nuts or popcorn |
| Soda | Seltzer with citrus |
| Frozen pizza | Whole-grain tortilla pizza with real toppings |
| Deli meat | Rotisserie chicken, or canned tuna |
| Instant noodles | Whole-grain pasta with frozen vegetables and an egg |
| Packaged sweets | Fruit with a square of dark chocolate |
Don't be afraid of convenient food
These are your friends: frozen vegetables and fruit, canned beans and fish, whole-grain bread, plain dairy, jarred tomato sauce with a simple ingredient list. They save you time and money, and they're fine. Our budget guide has more.
Sources
This guide is general information, not medical advice. Please check with a clinician before making big changes, especially if you have a health condition, take medication, or are pregnant. Read the full disclaimer.
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