Lightly Processed Foods Are Healthy. Ultra-Processed Foods Are Killing Us. How to Tell the Difference
by Nils Osmar
Consumers in the United States and many other industrialized countries are facing a problem. We’ve read warnings that ultra-processed foods are dangerous and are associated with increased risks of cancer, heart disease, and diabetes. Hundreds of studies have verified the connection between ultra-processed foods and disease.
For example, a 2025 study published in JAMA Oncology tracked 29,105 female nurses over 24 years and found that women who ate the most ultra-processed foods had a 45 percent higher risk of developing conventional adenomas—a type of precancerous colorectal polyp—before age 50, compared to those who ate the least. See study
What makes this finding particularly significant is that the association held even after researchers controlled for body mass index, diabetes, fiber intake, and overall diet quality. In other words, it’s not just that people eating ultra-processed foods happen to have worse diets overall—there’s something specifically harmful about the ultra-processing itself. On average, ultra-processed foods provided 34.8% of the participants’ daily calories, with a median of 5.7 servings per day.
The study used the NOVA classification system, the international standard for categorizing foods by their degree of processing, to distinguish ultra-processed foods from minimally processed ones—a distinction we’ll explore in detail below.
So we’re clear on the dangers. But we have only a vague sense of which foods fit this category. As a result, most of us are still filling up our cupboards and refrigerators with ultra-processed foods, and eating them routinely without knowing it.
The key thing many of us are missing is an understanding of the difference between processed and ultra-processed foods. In this article, I’ll be focusing on how to spot them and the importance of avoiding them completely, not just including them in moderation in our diets.
What Are Processed Foods?
For those wanting to build health and avoid disease, it’s essential to be aware of the difference between processed foods and ultra-processed foods.
The term “processed foods” simply means foods altered from their raw, natural state by traditional methods like cooking, freezing, or fermenting.
These foods, generally speaking, are fine to eat. They still retain much of their natural composition and nutritional value. Examples would be frozen blueberries, frozen meat, fish, and poultry, yogurt, kefir, fermented vegetables such as kimchi and sauerkraut, various cheeses, and smoked fish. Processed foods are not necessarily unhealthy; they can be important parts of a healthy, balanced, and nutritious diet.
What Are Ultra-Processed Foods?
Ultra-processed foods are industrially manufactured products with added flavors, colors, sweeteners, and other additives to make them more palatable and convenient.
Ultra-processed foods are highly industrialized, low-nutrient, and additive-rich products. The evidence is clear that eating “foods” like these strongly impacts our health. Their consumption is also driving up healthcare costs. They are associated with the rapid increase in the so-called diseases of aging, which are actually occurring younger and younger in the population due to our modern industrial diet.
Before Buying Packaged Foods of Any Kind, Check the Ingredient List For:
- Multiple unpronounceable ingredients
- Added sugars and other sweeteners
- Ingredients ending in “-ose” (like fructose, dextrose)
- Thickeners, stabilizers, or emulsifiers
- Hydrogenated or interesterified oils
- Food substances rarely used in home kitchens (e.g., high-fructose corn syrup, soy protein isolate)
In Summary:
- Ultra-processed foods are linked to higher risks of obesity, heart disease, diabetes, cancer, and early death.
- Over half of Americans’ daily calories come from ultra-processed foods, which are often affordable and heavily marketed.
- Reducing consumption of ultra-processed foods can improve overall diet quality and lower health risks.
- Avoiding ultra-processed foods has multiple benefits including weight loss, reduced calorie intake, improved energy, and lower risk of chronic diseases such as heart disease, diabetes, and metabolic syndrome.
What to Do?
The solution is straightforward: avoid buying packaged junk. When in doubt, don’t buy it. Whatever your diet—whether you’re vegan, carnivore, vegetarian, pescatarian, or eating a Mediterranean diet—buy real food and prepare it yourself.
How to Avoid Ultra-Processed Foods
- Focus on whole or minimally processed foods.
- If your diet includes grains, nuts, seeds, and legumes, start with whole ingredients.
- Buy fresh or frozen meats, seafood, eggs, poultry, and dairy.
- Canned foods should in theory be safe as long as they meet the above guidelines, but be aware that cans can include toxic plastic linings. So fresh or frozen is often better.
- Cook meals from scratch using basic ingredients to control what goes into your food.
- Avoid products with long ingredient lists, especially those containing unrecognizable chemical additives, emulsifiers, sweeteners, and artificial colors or flavors.
- Shop the perimeter of grocery stores, where fresh and whole foods tend to be located, and avoid the inner aisles.
It’s not that hard really to avoid the latter completely. We just have to give it some thought, in particular in relation to snacks.
What About Snacks?
Snacks can be a special problem. Many of us are in the habit of buying real, whole good ingredients to use when preparing meals, but reach for snacks when we’re hungry between meals without really thinking about what’s on the label.
If you buy protein bars, for example, buy ones with short lists of recognizable ingredients. Remember that the inclusion of one healthy ingredient such as whey in protein bars does not negate the damage being done by the other ingredients in the same bars.
Avoid ready-to-eat meals, sugary beverages, and fast food. Look for snacks that are free of additives, such as nuts, cheese, smoked fish, apples, berries, and protein bars with very limited ingredients.
Understanding the NOVA Classification System
The NOVA classification system, developed by researchers at the University of São Paulo in Brazil, is the most widely used framework for categorizing foods based on the extent and purpose of their processing. It’s now used in research worldwide and has become the standard for identifying ultra-processed foods. Unlike systems that focus only on nutrients (like fat or sugar content), NOVA looks at how much a food has been industrially transformed from its original state.
NOVA divides all foods into four groups:
Group 1: Unprocessed or Minimally Processed Foods
These are whole foods or foods altered by simple processes like drying, freezing, or pasteurizing—changes that don’t add new substances to the original food. Examples include fresh, frozen, or dried fruits and vegetables; eggs; fresh or frozen meat, poultry, and fish; plain milk; dried beans and lentils; nuts and seeds; plain yogurt; and herbs and spices.
These foods form the foundation of a healthy diet.
Group 2: Processed Culinary Ingredients
These are substances extracted from Group 1 foods or from nature, used in cooking to prepare and season Group 1 foods. Examples include oils pressed from olives, seeds, or nuts; butter; sugar; salt; and honey.
These ingredients aren’t meant to be eaten by themselves but are used to make whole foods more flavorful and digestible.
Group 3: Processed Foods
These are relatively simple products made by adding Group 2 ingredients to Group 1 foods, usually to preserve them or enhance their flavor. The key here is that these foods are recognizable as modified versions of Group 1 foods and typically contain just two or three ingredients. Examples include canned vegetables with added salt; canned fish; freshly made unpackaged bread; cheese; and smoked or cured meat without added preservatives beyond salt and smoke.
Processed foods can be part of a healthy diet when consumed thoughtfully.
Group 4: Ultra-Processed Foods
This is where things go wrong. Ultra-processed foods are industrial formulations typically with five or more ingredients, many of which you’d never use in home cooking. They contain substances extracted from foods (like casein, lactose, whey, and gluten), modified through chemical processes (like hydrogenated oils or hydrolyzed proteins), or synthesized in laboratories (like artificial colors, flavors, and various additives used to make the final product more appealing or shelf-stable).
Common examples include soft drinks; packaged snacks like chips and cookies; most breakfast cereals; energy bars with long ingredient lists; instant noodles; chicken nuggets; hot dogs; mass-produced packaged breads; margarine; ice cream; and ready-to-heat meals.
The crucial distinction is that ultra-processed foods are designed in laboratories and manufactured in factories using ingredients and processes unavailable in home kitchens. They’re engineered for maximum palatability, convenience, and profit—not for your health.
Why NOVA Matters
The beauty of the NOVA system is its simplicity. You don’t need to count calories or calculate macros. You just need to ask: How far has this food traveled from its natural state? How many industrial processes has it been through? Would my great-grandmother recognize this as food?
If a product has been broken down, chemically modified, and reassembled with additives to make it hyper-palatable and shelf-stable, it’s Group 4—and it’s time to put it back on the shelf (or in the trash, if you’ve already bought it).
The NOVA classification is endorsed by many global health organizations, including the Pan American Health Organization and the Food and Agriculture Organization of the United Nations, as a standard tool in nutrition research and public health policy for understanding the health impacts of food processing.
“Moderation” Kills
I’m going to end with a recommendation that will bother many people. But I would encourage people to consider carefully what I’m saying.
There has been an increase recently in the number of articles addressing problems associated with ultra-processed foods. This is great from my perspective. But one gripe I have with them is that they almost always end with the advice to go ahead and eat some UPFs, but to do so “in moderation.”
This is similar, from my perspective, to telling someone to smoke cigarettes ‘in moderation’—while ignoring the fact that the tobacco companies (like the “food” companies in question) have spent decades trying to engineer addictiveness.
What exactly is “moderation” when it comes to ultra-processed foods supposed to mean? How much is too much? Is one bar filled with a list of 30 ingredients we can’t pronounce fine, but two will kill us?
Moderation can work for natural treats. But the truth is that the products in question are designed to defeat moderation. They are designed by intention to bypass satiety signals and promote overconsumption, making ‘moderation’ unrealistic.
“Oh, it’s just one cookie. Well, OK, it actually turned out to be a bag of cookies. But I don’t eat cookies every day. Let’s see now… I’ll just pop this ultra-processed pizza in the microwave and have an ultra-processed drink that has 20 chemicals in it as a chaser. It has water in it! Oh, and it’s 10% fruit juice! I’m sure that will balance out all the chemicals.”
Once we start down that path, we need to face that we’re moving in the direction of disease, not health. We’re trading long-term health for short-term convenience.
Just Be Real
It takes thought and attention to start avoiding ultra-processed foods, and even more so to set a goal of avoiding them completely. We’re surrounded by fake food, which is convenient but harmful.
The key thing… the takeaway, from my perspective… is to “just be real.” Buy real, whole foods and prepare it yourself.
Check your cupboard and refrigerator, and if they have any ultra-processed foods in them, toss them out. I just did so myself, and I’ll confess that I found four items which fit in the ultra-processed category. I found myself rationalizing: “Well, it’s only four… I spent good money on them, it would be a shame to waste them.”
I won’t say that I cried when I threw them in the trash, but it was a reminder that we’re not only wasting our health when we buy junk like this, we’re also wasting money.
In closing, I would say, if you find yourself starting to eat ultra-processed foods again in the future, don’t blame yourself; they’re designed to be addictive. As a friend of mine used to say, when it comes to building health, it’s fine to “Start over every morning.” Just deep-six them, recommit to doing right by yourself. Remember that you (and your health) matter. Taking care of yourself is a way of taking care of your loved ones, by lowering the odds that they will end up needing to care for someone who has cancer, heart disease, or diabetes.
Take care and stay healthy.
