By Andrea Petersen

New research is helping to answer an important question about ultra-processed foods: Which ones may be healthier?

One reason many ultra --processed foods often lead us to eat big meals and heavy snacks is because of their texture, which makes them go down easily and quickly, according to a new study presented this week at a conference of the American Society for Nutrition in Orlando, Fla.

But some diets filled with ultra-processed foods don't cause us to eat as much. People in the study who had a diet of slower-to-eat ultra-processed foods such as crunchy breakfast cereal and multigrain buns consumed an average of 369 fewer calories a day than when they were eating quick-to-eat ultra-processed foods such as commercially made smoothies and soft breads.

"Meals that are equally satisfying were eaten in different ways purely as a function of the way they're textured," said Ciarán Forde, a professor at Wageningen University in the Netherlands, who led the study.

Concern is rising about ultra-processed foods, a category of items that can include everything from sodas and candy to soups and breads. The Trump administration's recently released "Make America Healthy Again" report points to ultra-processed foods as a major cause of children's health problems. Health Secretary Robert F. Kennedy Jr. has said he expects the updated version of the federal dietary guidelines, slated to be released this summer, to advise Americans to avoid packaged items.

Nutrition researchers generally define ultra-processed foods as something that contains ingredients that aren't generally found in a home kitchen, like emulsifiers and high-fructose corn syrup. Studies have linked diets high in ultra-processed foods to increased risks of obesity, Type 2 diabetes, cancer, cardiovascular disease and depression. But many scientists believe not all packaged foods are equally bad -- and some might be relatively healthy.

The texture of many ultra-processed foods is just one way scientists believe they can drive people to consume excess calories. Other research has found that products such as energy bars, chips and frozen meals pack more calories per gram than less processed foods do. Many packaged foods also have combinations of salt, fat and carbohydrates that aren't generally found in nature, a quality that can make us crave them.

In the new study, participants spent two weeks each on two diets that contained more than 90% of calories from ultra-processed foods. In one diet, most meals had textures with fast eating rates, and people ate them at a rate of about 50 to 60 grams a minute. Dishes included meatballs with mashed potatoes and a sandwich of cheese and butter lettuce on a soft wheat bun.

In the other, most meals had a slower eating rate, or around 30 grams a minute. Dishes on this diet included fried noodles with beef strips and cabbage and a sandwich of cheese and iceberg lettuce on a harder multigrain bun.

Participants were served the same number of calories on both diets. The two diets were also matched for calories per gram, sodium and fiber content, portion size and percentage of ultra-processed foods served. Participants were told to eat until they felt full and could eat as much as they wanted.

The study subjects reported that they liked the diets equally and felt just as satisfied on both. But after two weeks on the slower diet, they lost an average of .43 kilograms of fat.

The study sheds new light on how ultra-processed foods affect calorie consumption over the short term, but that isn't the only concern, said Dr. Dariush Mozaffarian, a cardiologist and director of the Food is Medicine Institute at Tufts University.

"Ultra-processed foods can affect the gut microbiome, they can affect insulin sensitivity, they can affect cancer risk," he said. Even if you can create a diet full of ultra-processed foods that makes you eat less, you could "be sicker because it's harming your health in other ways." Indeed, some studies have found that certain additives in many ultra-processed foods, like emulsifiers and coloring agents such as titanium dioxide, are linked to health problems.

The new study's funders include the Dutch government and the food industry, including major companies like Nestlé, General Mills and Unilever.

Forde said that food texture is complex, and he notes that minimally processed foods, too, have different eating rates that affect how much we consume.

He suggests choosing foods you enjoy but steering away from high-calorie, softly textured items. (Think a whole baked potato over buttery mashed potatoes.) Be careful with very saucy dishes with small bits of food, such as sauced minced meats or stews, which can go down quickly. And you can slow down your eating rate, and eat less, by going for items that will take longer to chew, such as a hard roll instead of a squishy piece of bread.

Write to Andrea Petersen at andrea.petersen@wsj.com

(END) Dow Jones Newswires

June 03, 2025 11:48 ET (15:48 GMT)

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