The results presented indicate that eating a healthy diet does not lead primarily to minimally processed foods

A new study shows that a healthy diet does not automatically lead to eating mainly processed foods, as defined in the NOVA classification system, suggesting that the types of food we eat may matter more than the level of processing. used to make them. .

Compare two menus that represent a typical Western diet -; one emphasizing minimally processed foods and the other emphasizing ultra-processed foods, as categorized by the NOVA classification system -; the researchers found that the less processed menu was more than twice as expensive and reached its expiration date three times faster without delivering any additional nutritional value.

“This study shows that it is possible to eat a low-quality diet even when choosing mostly processed foods,” said Julie Hess, PhD, a research nutritionist at the USDA-ARS Grand Forks Human Nutrition Research Center, who was in led the study. “It also shows that more processed and less processed diets can be equally nutritious (or non-nutritive), but the more processed diet may have a longer shelf life and be less expensive.”

Mark Messina, PhD, director of nutrition science and research at Soy Nutrition Institute Global, will present the findings at NUTRITION 2024, the main annual meeting of the American Nutrition Association held June 29-July 2 in Chicago.

The new research builds on a study published by the team last year, which showed it was possible to create a high-quality menu that aligns with dietary guidelines while deriving most of its calories from foods classified as ultra-processed. . For the new study, the researchers asked the opposite question: Is it possible to build a low-quality menu that gets most of its calories from “simple” foods?

To find out, they created a less processed menu, which derived 20% of its calories from ultra-processed foods, and a more processed menu, which derived 67% of its calories from ultra-processed foods. The level of processing involved in each menu was determined according to the NOVA classification system.

Both menus were calculated to have a Healthy Eating Index score of about 43-44 out of 100, a relatively low score that indicates poor compliance with the Dietary Guidelines for Americans. The researchers estimated that the least 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 time to expiration of the less processed menu items was 35 days versus 120 days for the more processed menu items.

The study draws attention to the disconnects between food processing and nutritional value. Hess noted that some nutrient-dense packaged foods can be classified as ultra-processed, such as unsweetened apples, ultra-refined milk, liquid egg whites and some brands of raisins and canned tomatoes.

The results of this study show that there is more to building a nutritious diet than considering food processing as defined by NOVA. The concepts of ‘ultra-processed’ and ‘unprocessed’ foods need to be better characterized by the nutrition research community.”

Julie Hess, PhD, research nutritionist at the USDA-ARS Grand Forks Human Nutrition Research Center

Messina present this research at 12:45-1:45 pm CDT on Sunday, June 30, during the Food Choices, Markets and Policy poster session in McCormick Place (abstract; presentation details below).

Objectives: The “clean eating” trend of eating mainly foods with simple ingredients suggests that eating fewer processed foods is an essential part of healthy dietary patterns. But research shows that a menu consisting mostly of ultra-processed foods (UPFs) can meet nutrient quality and dietary recommendations from the Dietary Guidelines for Americans. Whether a diet consisting mostly of simple ingredient foods can provide a low quality diet remains unexplored. The purpose of this study was to compare the diet quality, shelf stability, and cost of two similar Western-style menus, one containing energy primarily from UPFs and the other containing energy from more less processed, as defined by the Nova food classification system. .

Methods: First, a less processed version of the Western menu (less processed Western, LPW; more processed Western MPW) with a Healthy Eating Index (HEI) score of approximately 43 was developed to align with the HEI score the previously developed MPW. . The level of processing was determined by Nova categorizations assigned by external graders. The final menu was assessed for nutrient content and HEI score. The shelf stability of the foods was determined with information from the food storage instruction manuals. The condition of each food item when purchased (shelf stable, frozen, refrigerated) was used to estimate the number of days until it expired. Food and menu costs were determined using Midwestern grocery chain retail prices in Fall 2023.

Results: The LPW and MPW had similar nutrient density and HEI scores (44 and 43, respectively). The LPW included 20% energy (kcal) from UPFs, and the MPW included 67% energy from UPFs. The relative percentages of shelf-stable, frozen and refrigerated foods were the same between the two. Using the Kaplan-Meier survival analysis method, the median time to expiration for the LPW menu items was 35 days versus 120 days for the MPW menu items. The “per person” cost was $34.87 per day for the LPW and $13.53 per day for the MPW.

Conclusions: Both the less processed and the more processed menus provided low quality diets. However, the LPW was more than twice as expensive as the MPW and had a shorter overall shelf life. The level of processing is not a proxy indicator of diet quality, and less processed foods can be more expensive and have a shorter shelf life.

Funding Sources: USDA Agricultural Research Service project grant #3062-51000-057-00D