Most of the Foods We Eat Are Ultra-Processed. Are They All Unhealthy?

Two people are standing in line at the grocery store. One has a cart full of instant ramen, hot dogs, ice cream, and soda, and the other has a cart full of whole grain bread, breakfast cereal, creamy reduced-fat peanut butter, and strawberry yogurt. Which one is buying ultra-processed foods (UPFs)?

It’s a trick question. The answer is: both.  

UPFs have become a popular topic of conversation, and a growing concern in public health. These foods are associated with worse diet quality and a long, ever-expanding list of adverse health outcomes. But what classifies as an ultra-processed food?  

The majority of the foods that we eat in the United States, says Julia Wolfson, PhD ’16, MPP, an associate professor in International Health. “They dominate our food systems. If you imagine a typical grocery store, most of the foods and beverages lining the shelves are ultra-processed.”  

In fact, nearly 75% of the U.S. food supply is estimated to be ultra-processed. More than half of the calories that the average American adult consumes come from UPFs; in children, that number is more than 60%. 

But not all ultra-processed foods are equally concerning. Teasing out what UPFs fall under the moniker of “junk food,” is more nuanced. And finding ways to reduce consumption is even more complicated.  

What Makes a Food “Ultra-Processed”

“Food processing has existed in some form throughout most of human history,” Wolfson says. One of the earliest examples is cooking with fire, and later, preservation methods like drying, smoking, curing, pickling, canning, and salting became commonplace. Traditionally processed foods include items like homemade breads, cheese, and canned fish, which are altered from their natural state by adding salt, fat, sugar, or oil. UPFs, however, are substantively different. 

The term “ultra-processed foods” originated from the Nova food classification system, which defines food in four categories, ranging from least to most processed: 

• Unprocessed or minimally processed foods like fruit, vegetables, milk, or fish.
• Processed culinary ingredients like salt, sugar, olive oil, and butter.
• Processed foods, such as jam, pickles, or canned fruit.
• Ultra-processed foods, like energy drinks, instant oatmeal, sliced bread, or hot dogs. 

Ultra-processed foods have one or more ingredients that wouldn’t be found in a kitchen, like chemical-based preservatives, emulsifiers like hydrogenated oils, sweeteners like high fructose corn syrup, and artificial colors and flavors. UPFs undergo processing techniques like pre-frying, molding, extrusion, fractioning, and other chemical alterations that leave the final products bearing almost no resemblance to the original ingredients. 

UPFs Are Ubiquitous and Appealing

Examples of ultra-processed foods that might instantly spring to mind include sodas, prepackaged snacks such as chips, cookies, crackers, candy, boxed macaroni and cheese, frozen and ready-to-eat meals, lunch meats, jerky, and hotdogs. 

The processes and ingredients used to create UPFs often make these foods hyperpalatable, Wolfson says, meaning they are designed to be exceptionally appealing to the human palate—and can be addictive. Ultra-processed foods typically contain a combination of ingredients like sugar, fat, and salt that stimulate the brain's reward system, making it hard to stop eating them.  

UPFs also reduce satiety, because industrial processing alters their structure, making them softer and easier to eat and digest. This leads to a faster rate of consumption, which can override natural fullness signals and cause people to overeat. Additionally, UPFs often contain additives and have lower levels of fiber, leading to less sustained fullness. 

Because ultra-processed foods are typically high in saturated fat, sodium, and sugar, and lower in water and fiber content, they are also more calorie-dense per gram (approximately 378 calories per 100 grams) compared to whole foods like fruits and vegetables (around 68 calories per 100 grams).  

“Many of these ultra-processed foods are intentionally designed by the food industry to be irresistible to consumers, and they’re heavily marketed with the goal of maximizing profits,” says Wolfson. “It might not be something to worry about if they comprised just a small proportion of the foods that we eat, but that’s not the case.” 

Some UPFs Are Less Unhealthy Than Others 

Not all ultra-processed foods are equally concerning for health. 

“Many ultra-processed foods are junk foods, but many others are products that we use all the time to feed our families, and we incorporate them into the meals that we cook every day,” Wolfson says. 

Prepackaged whole grain breads, many yogurts, instant oatmeal, and jarred pasta sauces are all ultra-processed foods, but have lower levels of saturated fats and added sugars while still containing a plethora of nutrients that help reduce disease risk. Baked beans, which contain protein, fiber, and minerals like iron and potassium, are ultra-processed, but consumption of beans has been shown to support heart health by lowering cholesterol, improve digestive health through fiber, and help stabilize blood sugar.

“Dairy alternatives like soy milk and or meat alternatives—these are ultra-processed and can be beneficial,” Wolfson says. “It's a balancing act. It's important to identify foods that are of most concern for health … I would like to see the Dietary Guidelines for Americans strike that balance in clear recommendations while not treating all ultra-processed foods with the same broad brush.” 

What Makes UPFs Unhealthy 

Ultra-processed foods are associated with worse diet quality and a long and growing list of adverse health outcomes. A 2024 umbrella review of 45 meta-analyses including almost 10 million people found that diets high in UPFs are linked to 32 health conditions, including obesity, type 2 diabetes, cardiometabolic diseases, many cancers, gastrointestinal disorders, asthma, anxiety, depression, cardiovascular events, and all-cause mortality. 

Ultra-processed meats (any meat that has been processed to change its shape, flavor, and freshness), for example, have been classified by the WHO as a Group 1 carcinogen—a categorization shared by tobacco and asbestos—for their link to colorectal cancer. A study published in JAMA Oncology in November found that, compared with women with healthier diets, women who eat a lot of UPFs are 1.5 times more likely to develop pre-cancerous polyps before the age of 50.

Sodas have some of the strongest evidence for health harms, says Wolfson. Heavily manufactured with additives, high levels of sugar or artificial sweeteners, and lacking essential nutrients, these beverages appeal to us on a biological level: For early humans, sugar was a rare and valuable source of calories, and the ability to detect and desire it helped ensure they got enough energy to survive. But today’s sodas deliver large amounts of pure sugar or high-fructose corn syrup in a way that our ancestors never encountered and lead to potential health issues like obesity, heart disease, type 2 diabetes, and others.  

The disassembling and reassembling of chemical and physical structures caused by processing affects how our bodies metabolize these foods, making them "pre-digested." This leads to rapid absorption of sugar and fat and spikes in blood glucose. It also bypasses the need for the body to break down food, which can lead to a disrupted gut microbiome because of low fiber content and potential harm from additives like emulsifiers. Over time, this can increase the risk of inflammatory bowel diseases, insulin resistance, and other health issues. Some research has shown that our bodies absorb more calories from UPFs than foods that have been minimally processed.

Reducing UPF Consumption 

Ultra-processed foods have been a major talking point among top U.S. health officials this year, mostly notably Health and Human Services Secretary Robert F. Kennedy Jr., who called them “poison” and has vowed to remove them from programs like SNAP.

When it comes to realistic solutions to reducing ultra-processed food consumption, “a lot of options are on the table,” Wolfson says. For example, educating the public about ultra-processed foods through improved front-of-package food labels. This “could help consumers make different choices and also prompt the food industry to reformulate some products so that they wouldn't get that label.”

Taxes and policy changes are viable options. Many countries, and some U.S. communities, now have soda taxes that decrease intake, for example. In June, California voted to enact the first U.S. law to define and ban unhealthy ultra-processed foods from an estimated over 1 billion meals served to California schoolchildren in the 2025–2026 school year.

But recognizing that these foods are widely used—and why—would be crucial. UPFs are shelf stable, unlike fresh produce. They save time, effort, and mental energy while cooking. Most importantly, they are more affordable. UPFs cost 55 cents per 100 calories, compared with $1.45 for unprocessed foods. 

“Time consideration, accessibility, and affordability—these are really big barriers to being able to consume less ultra-processed foods,” says Wolfson. “We are balancing work and childcare and other responsibilities as well as our household budgets and needing to get food on the table every single day. Ultra-processed foods are so widely consumed because they fill a need.” 

If policy changes, taxes, labeling, or other messaging around the dangers of ultra-processing are put into action, “we need to help people afford the alternative,” Wolfson says, pointing to expansion of healthy food incentive programs, more sufficient SNAP benefits, and advocating for equitable minimum wage laws that allow people to afford a diet that is more minimally processed. 

On an individual level, reducing or eliminating UPF intake can be a gradual process. If at all possible, you should: 

• Keep lots of healthy foods at home and try not to purchase UPFs when at the grocery store.
• Try preparing meals at home in advance that use less processed foods.
• Read the nutrition labels and ingredient lists on products before you buy them, looking for foods that have only a few pronounceable, recognizable ingredients.  
• Try replacing an ultra-processed food with fruit or vegetables. Use minimally processed frozen or canned options if fresh fruit or vegetables aren’t available.
• Replace sugary beverages with water.
• Choose whole grains, like whole wheat bread, over processed grains like white bread.
• Make a homemade version of a processed food, like sweet potato chips, healthy muffins, bread, or salad dressings.
• Choose healthier menu options when eating out, like salmon with steamed vegetables instead of a hamburger.