PRIORITIZING NUTRIENT CONTENT OVER LEVEL OF PROCESSING IN FOOD EVALUATION AMIDST THE ULTRA-PROCESSED FOOD DEBATE

“High UPF [ultra-processed food] consumption is associated with an increased risk of a variety of chronic diseases and mental health disorders. At present, not a single study reported an association between UPF intake and a beneficial health outcome.”1 This statement, which comes from a recently published umbrella review of 39 meta-analyses of observational studies, should concern all health professionals, but especially those in the United States because by one estimate, Americans get 58% of their calories from UPFs; more than any other country, and in most instances, markedly so.2

Nova Food Classification System Defines Ultra-processed Foods

The definition of UPF used by the authors of the aforementioned umbrella review was crafted in 2009 by Brazilian researchers who created the Nova food classification system, which divides all foods into four categories based ostensibly on the extent to which they have been processed, though formulation (e.g., whether a food contains an additive) is also considered.3 While many foods classified as ultra- processed are high in fat, sugar, and sodium, nutritional quality is not a consideration in the classification of UPFs. In fact, Julie Hess and colleagues4 recently showed that it is possible to devise a diet based almost exclusively on UPFs that results in a healthy eating index score of 86 out of 100, which is far greater than the average score for Americans of 59. Australian researchers found that of the more than 25,000 products analyzed, 1/3 of foods Nova-classified as ultra-processed received at least 3.5

stars based on the Health Star Rating system (5 stars being the highest score) whereas 1/3 of foods not classified as ultra-processed received fewer than 3.5 stars.5

Research on UPFs has increased markedly in recent years, an observation supported by the exponential increase in peer-reviewed publications on this topic. In 2023, 574 papers indexed in PubMed were related to UPFs whereas a decade earlier that figure was only nine. Another indication of the interest in UPFs is that the 2025 U.S. Dietary Guidelines for Americans Advisory Committee (subcommittee 1) is tasked with addressing the question, “What is the relationship between consumption of dietary patterns with varying amounts of ultra-processed foods and growth, body composition, and risk of obesity?”

Impact of Ultra-processed Foods on Soy Food Perception

The emergence of Nova potentially impacts the perception of many soy foods because 90% of all plant milks, including soymilk made from whole soybeans, and the entire new generation of plant meats based on concentrated sources of protein, such as soy protein isolate and soy protein concentrate, are classified as UPFs.6 While it is beyond the scope of this article to comprehensively evaluate the merits of Nova, it makes little nutritional sense to place calcium and vitamin D-fortified soymilk, protein-rich soy burgers, and packaged snack cakes in the same category, and therefore to conclude that they similarly affect health. And yet, that is in essence what Nova does.

Nova paints with a very broad brush, which is evidenced by the results of several observational studies which show that although total UPF intake is associated with adverse health outcomes, subgroups of UPFs are often not associated with risk or are associated with a decreased risk.7-13 For example, a recently published analysis of a multinational cohort found that higher UPF consumption was associated with an increased risk of multimorbidity of cancer and cardiometabolic diseases. However, whereas ultra-processed animal-based products and artificially and sugar-sweetened beverages were associated with marked increased risks, plant-based alternatives were associated with a non- significant decreased risk.7 Similarly, although a combined analysis of three large U.S. cohorts found total UPF intake was associated with an increased risk of developing diabetes, the hazard ratio for seven of the 14 subgroups of UPF was below 1.00 (indicating a protective association).8

Analyzing Nutrient Content and Level of Processing

When considering the two major categories of plant-based alternatives, plant milk alternatives and plant meat alternatives, it is the latter that have been most heavily criticized for the extent to which they are processed. When the merits of plant milks are evaluated, it is typically based on nutrient content and often in comparison to cow’s milk. However, it is one thing to compare nutrient content and another to compare health outcomes. In a forthcoming analysis of randomized controlled trials (RCTs), researchers from the University of Toronto have done just that. See the article by Erlich and Sievenpiper in this issue for more details.

Conclusion

In several recently published RCTs, the health effects of plant-based meat alternatives have been compared to meat, which is Nova-classified as unprocessed or minimally processed.14-17 Overall, these trials show that health effects are driven by nutrient content, not by processing level. However, the trials were only four to eight weeks in duration, which may be too short to see all potential differences. One recent analysis did find that the common attributes of UPFs (e.g., hyperpalatability, calorically dense, soft texture) do not apply to soymilk or soy burgers more so than to their animal-based counterparts, cow’s milk or meat, respectively, even though the former are classified as UPFs and the latter as unprocessed or minimally processed foods.18 So, while it is fair to say that more mechanistic work aimed at understanding the health effects of UPFs is needed, considerable evidence indicates that when evaluating foods, emphasis should continue to be placed on nutrient content.

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