Limiting ultra-processed foods (UPFs) may not always result in a healthy and nutritious diet, experts have said. UPFs are widely viewed as unhealthy because they contain high amounts of saturated fat, sugars, and salt. However, scientists have pointed out that cutting down on UPFs may not necessarily lead to a healthier diet. This is because the system used to label foods based on the level of processing, known as Nova, does not take into account nutritional values.
For example, some packaged foods such as unsweetened apple sauce, filtered milk, liquid egg whites, and certain brands of raisins and canned tomatoes can be classified as ultra-processed, even though they are considered “nutrient-dense” by the team of researchers. On the other hand, certain foods labeled as minimally processed by Nova can be more expensive, have a shorter shelf life, and provide a poor diet.
Presenting their findings at the American Society for Nutrition conference in Chicago, Dr. Julie Hess, a research nutritionist at the United States Department of Agriculture (USDA), stated, “This study indicates that it is possible to eat a low-quality diet even when choosing mostly minimally processed foods.” She also highlighted that more-processed and less-processed diets can be equally nutritious or non-nutritious, but the more-processed diet may have a longer shelf life and be less costly.
In a study conducted by the researchers, two breakfast menus were created, both containing jam on toast and eggs cooked in different ways. The “less-processed” menu, featuring homemade jam and bread and poached eggs with bacon, derived 20% of its calories from UPFs. On the other hand, the “more-processed” breakfast, which included store-bought jam and bread, egg toast with ham, and hash browns, derived 67% of its calories from ultra-processed foods.
Both meals received a “low” score of about 43-44 out of 100 in the Healthy Eating Index, a tool used to measure diet quality based on how well it aligns with the Dietary Guidelines for Americans. However, the less processed menu was more than twice as expensive and reached its expiry date over three times faster without delivering any additional nutritional value, according to the researchers.
Dr. Hess emphasized, “The results of this study indicate that building a nutritious diet involves more than a consideration of food processing as defined by Nova.” She suggested that the concepts of ultra-processed foods and less-processed foods need to be better characterized by the nutrition research community.
Commenting on the research, Dr. Hilda Mulrooney, a reader in nutrition and health at London Metropolitan University, pointed out a major flaw in the Nova classification system. She stated that the system distinguishes foods only based on their degree of processing and not on their nutritional value. Dr. Mulrooney highlighted that rejecting foods solely based on their degree of processing could eliminate many foods that could add considerable nutritional value to diets.
In the UK, many foods classified by the Nova system as ultra-processed, such as some breakfast cereals and high-street breads, make important contributions to a person’s dietary intake. Dr. Mulrooney warned that without these foods, there is a risk that some groups might not meet the recommended intakes of key nutrients. She also emphasized that cost is a crucial consideration when choosing what foods to eat, as foods that last longer and are affordable are likely to be more attractive options for many individuals.
In conclusion, the research funded by the USDA Agricultural Research Service project grant sheds light on the limitations of solely focusing on the level of food processing when determining the nutritional value of a diet. It is essential for the nutrition research community to consider a more comprehensive approach that takes into account both the processing level and the nutritional content of foods to promote a healthy and balanced diet.