NEW YORK, June 30 (UPI) — A diet that limits ultra-processed foods isn’t automatically healthy, and the types of foods people eat may matter more than the level of processing used to make them, a new study suggests.
The results were presented Sunday at the annual meeting of the American Society for Nutrition in Chicago.
The researchers compared two menus that reflect a typical Western diet: one that emphasizes minimally processed foods and one that focuses on the ultra-processed variety, according to the NOVA food classification system.
This system classifies foods into four groups based on criteria related to their processing. It was designed by the Center for Epidemiological Studies on Health and Nutrition of the School of Public Health of the University of Sao Paulo, Brazil.
The less processed menu cost more than twice as much and reached its expiration date more than three times faster without providing any additional nutritional value.
This finding demonstrated that “both ultra-processed and less-processed foods can have a low healthy eating score,” Allen Levine, professor emeritus in the department of food sciences and nutrition at the University of Minnesota in St. Paul, told UPI by email.
Levine classified the different foods into the NOVA system for the study.
“Additionally, ultra-processed foods with a similar healthy eating score to less processed foods have a longer shelf life and are less expensive,” Levine said.
Based on these findings, it is possible to consume a poor-quality diet even when choosing primarily minimally processed foods, the researchers noted.
“The results of this study indicate that developing a nutritious diet involves more than simply considering food processing as defined by NOVA,” Julie Hess, the study’s lead researcher, said in a press release.
“The concepts of ‘ultra-processed’ foods and ‘less processed’ foods need to be better characterized by the nutrition research community,” said Hess, a nutrition researcher at the U.S. Department of Agriculture/Agricultural Research Service’s Grand Forks Human Nutrition Research Center.
Last year, the team published a study showing that it was possible to create a high-quality menu that met dietary guidelines while getting most of its calories from foods classified as ultra-processed.
For the new study, the researchers asked the opposite question: Is it possible to create a low-quality menu that gets most of its calories from “simple” foods?
To answer this question, they developed a less processed menu, with 20% of calories coming from ultra-processed foods, and a more processed menu, with 67% of calories coming from ultra-processed foods. The NOVA system determined the level of processing involved in each menu.
The researchers calculated that the menus had a healthy eating index of about 43 to 44 out of 100, a relatively low number that reflects low adherence to dietary guidelines for Americans.
They estimated that the less processed menu would cost $34.87 per day per person, compared to $13.53 per day for the more processed menu. They also calculated that the median expiration time for less processed menu items was 35 days, compared to 120 days for more processed menu items.
The study highlights the disconnect between food processing and its nutritional value, the researchers said. Some nutrient-dense packaged foods can be classified as ultra-processed, such as unsweetened applesauce, ultrafiltered milk, liquid egg whites and some brands of raisins and canned tomatoes.
“When it comes to eating healthy and affordable food, nutritional quality and price can be a combination,” said Joan Salge Blake, a registered dietitian, clinical professor and director of nutrition programs at Boston University. She was not involved in the study.
Blake recommends using the grocery store’s catalog or app to find healthy foods — whether fresh, frozen, canned or packaged — that are on sale and planning your weekly meals around those items.
“Use the Nutrition Facts panel on the label as a guide to help you decipher the nutritional quality of the foods you choose rather than being scared off by their level of processing,” she said.
However, ultra-processed foods can contribute significantly to obesity and related chronic diseases if they contain high added sugars, unhealthy fats and artificial additives and have low nutritional value, said Dr. Zhaoping Li, professor of medicine and director of the Center for Human Nutrition at the David Geffen School of Medicine at the University of California, Los Angeles.
“Ultra-processed foods were initially developed to provide convenient and affordable sources of calories to prevent malnutrition,” Li said, adding that they have become increasingly popular because they often appeal to consumers’ taste preferences with ready-to-eat or ready-to-prepare formats.
She advises replacing ultra-processed foods with fresh, nutrient-dense foods whenever possible.
A diet consisting of whole grains, lean proteins, healthy fats, fruits and vegetables “ensures that the body is getting the vitamins, minerals and other beneficial compounds it needs,” Li said.
“Prioritizing diet quality can help prevent chronic disease, improve energy levels and support overall well-being,” she added.
The study sends a broad message that the health value of foods is about more than how much processing they undergo to reach consumers, said Liz Weinandy, a registered dietitian and instructor of practice at The Ohio State University Wexner Medical Center in Columbus.
“I don’t think anyone would argue, though, that sugary drinks, candy and chips have little nutritional value and shouldn’t be consumed regularly,” Weinandy said. “We don’t want to put lipstick on a pig.”