A few months ago, I decided I would try making overnight oats as a healthier breakfast option than sugary drinkable yogurt. I found the oats aisle and just stood there, attempting to make sense of the four dozen options in front of me, in every form, flavor, and level of added sugar. They all looked equally “processed” to me. I gave up, leaving the store without oats and with a heavy load of emotional exhaustion. And that’s just the oatmeal section of the grocery store, never mind the stacks of snacks, drinks, and condiments.

Welcome to the new supermarket anxiety plaguing Americans who want to eat healthier but aren’t quite sure how. By now, you’re likely aware of the overwhelming, still growing evidence of the health risks of ultra-processed foods (UPFs), which links their overconsumption to a greater chance of premature death, as well as to plenty of its contributors: cognitive decline, dementia, depression and anxiety, several types of cancer, heart disease, inflammation, insulin resistance, and gastrointestinal and metabolic diseases. Yeah, rough.

What’s wild is that UPFs are a huge part of what we eat. The average American’s diet consists of about 57 percent UPFs; that jumps to about two-thirds for children and teens. Maybe that’s not surprising when you consider that up to 73 percent of the U.S. food supply is ultra-processed, according to a study by a Harvard and Northeastern University research group led by Giulia Menichetti, PhD.

Menichetti’s scientists are doing more than just counting UPFs. They and other researchers are also trying to make grocery store choices easier by tackling the surprisingly difficult task of figuring out exactly which UPFs are hurting us most and why. And they’re aiming to add nuance to the narrative that any UPF is bad for you. “Large population studies have begun to show that what is currently categorized as ultra-processed food may not be equally bad for our health,” Menichetti says.

Where the Dangers of UPFs Are

Knowing what makes one package of anything better than another means decoding why UPFs are linked to so many major health problems. Researchers don’t quite know yet. In fact, there’s not even a clear, specific definition of “ultra-​processed” that all scientists agree on.

What we’re not talking about is stuff like olive oil and frozen strawberries. Yes, these foods are processed, but oil pressing and flash freezing are considered minimal forms of processing, not ultra-processing.

The definition used by many researchers comes from the Nova classification system, developed by a team led by Brazilian scientist Carlos Monteiro, MD, PhD. Nova divides foods into four groups, from unprocessed or minimally processed to UPFs, which are foods made entirely or mostly from substances extracted from whole foods or synthesized in a laboratory. According to this system, UPFs are designed to be “hyper-palatable and attractive, with a long shelf-life.” Per one of Dr. Monteiro’s studies, they also tend to be “energy-dense, high in unhealthy types of fat, refined starches, free sugars and salt, and poor sources of protein, dietary fiber, and micronutrients.” So that would include cookies, sweet yogurts, energy drinks, instant soups, and food “nuggets.” Some critics say Nova puts too much weight on the number of ingredients in a product and the number of processes it goes through. Under its terms, some healthful homemade foods would be considered processed, such as hummus made from canned beans or made-from-scratch bread. Still, Nova is often used in studying exactly why UPFs do a number on your body.

How UPFs Affect Us

“There’s no shortage of really interesting and compelling-sounding theories about how ultra-processed food might impact human health,” says Kevin Hall, PhD, who’s doing dietary intervention studies on UPFs at the National Institute of Diabetes and Digestive and Kidney Diseases.

One effect is straightforward: “They make people eat more,” says Marion Nestle, PhD, a professor emerita of nutrition, food studies, and public health at New York University. Hall saw this in a groundbreaking 2019 study in which 20 people spent two weeks eating a diet of 81 percent UPFs. They then spent another two weeks eating a diet with the same amount of protein, fat, and carbs but from non-UPF foods. On both diets, they could eat as little or as much as they wanted. Given that the nutrient distribution was the same, Hall didn’t expect to see a big difference—but he proved himself wrong. On the UPF diet, people ate about 500 more calories a day and, unsurprisingly, gained weight.

You might think it’s obvious that people overeat UPFs because their fat, sugar, and sodium content makes them taste really good. Those extra calories can lead to obesity, which contributes to most of the health issues linked to UPFs, Nestle says. But other researchers think that answer is too simplistic and suggest it may be that the body absorbs UPFs so quickly that they don’t make us feel full. Or that these foods lack the fiber your microbiome needs to help manage your health.

It’s also possible that processing itself can change a food in unexpected ways. Anthony Fardet, PhD, a food scientist at France’s National Research Institute for Agriculture, Food and Environment, cites a theory that xenobiotics, or synthetic chemicals, might be damaging. These could be lab-made additives, or even compounds leached from packaging into the food itself. Either way, xenobiotics don’t exist in nature, he says, and we don’t know how they affect our biology.

Emulsifiers are coming under scrutiny as well. These are substances designed to stabilize UPFs by holding together two liquids, usually oil and water. Emerging research in top journals such as Gastroenterology indicates that some of these, such as polysorbate-80 (used in foods like ice cream) and the texture modifier carboxymethylcellulose (which could be in anything from sausages to baked goods to candy), can lead to inflammation in the gut. This could prevent adequate nutrient absorption and damage your metabolism. Other emulsifiers may be harmless; some may combine to cause trouble. So, it’s complicated. “The idea is to start looking at foods not only by considering one chemical at a time, one nutrient at a time, but by looking at how these different chemicals influence each other and how the overall profile of chemicals determines the quality of food,” Menichetti says.

We know this is a lot. And so do the scientists, who are only in the early stages of unpacking what makes UPFs so damaging.

So what are you supposed to do while researchers figure it out? Tech tools might help a bit (see below). But when you’ve got to go packaged, at least aim to offset the effects we know about so far:

• Pick the products that are lowest in added sugar—since added sugars are often a big sign of a less-healthy UPF. Same with sugar alcohols.

• Find ways to add omega-3s to your diet. A high-UPF diet generally doesn’t include much of these. Try having a meal with salmon or tuna each week.

• Load up on fiber, since a high-UPF diet can leave you lacking here. Make an effort: Your goal should be 30 to 38 grams a day, ideally from a variety of fruits, vegetables, whole grains, and legumes.

• Determine whether some of the foods you consume are actually increasing your hunger or your desire to eat. Consider tracking what you eat for a week. Do you notice that you eat more on certain days with certain types of foods? If you can identify which are more addictive for you, focus on alternatives to those.

Menichetti and her team want to make all of this easier by diving into the thicket of details so you don’t have to—so they’ve started a database, TrueFood, to help. And they’re also wishing that the food industry had better labeling and, ideally, better foods. Nestle echoes that, saying that better regulations could force the food industry to make healthier products. People trying to eat better are “fighting the entire food system on their own,” she says. “That’s really hard to do.”

But that doesn’t mean it’s impossible. Eventually, when I’m in the oats aisle, I’ll have great tools to help me. In the meantime, I’ll use the strategies on the left and try to choose as many foods as I can that look as close as possible to, well, food.

This article appears in the May/June 2025 issue of Men’s Health.