By Marie Latulippe of IAFNS
Those in the food and nutrition space who think the concept of classifying foods as “ultraprocessed” (UPF) was a passing trend are surely swayed by the daily barrage of new science, global policies and media stories. With food and nutrition conversations reaching executive levels of the U.S. government, we are still some distance from the end of this story.
Despite the term finding its way into the 2025-2030 Dietary Guidelines Advisory Committee’s (DGAC) set of systematic reviews, we are still left without resolution. The DGAC had difficulty evaluating the literature on this question, “largely because of the lack of a clear definition of ultra-processed foods.”
The Institute for the Advancement of Food and Nutrition Sciences (IAFNS) is soliciting input on science-based principles for food classification from the food and nutrition community at a public workshop in April and through other mechanisms, to ensure viability and alignment. More on that later.
One aspect of these conversations that lends itself to more agreement than not seems to be the need to understand the biochemical and physiological mechanisms underlying the apparent associations between UPF intake and the wide variety of health outcomes examined in observational studies.
As we still await the completion of many critical studies (see clinicaltrials.gov), some global authorities are moving forward with recommendations to limit the intake of foods classified as UPFs in the diet and identify them on store shelves. Others are inclined to hold out for more specifics.
These discussions have intensified without resolution since the IAFNS May 2023 Food Classification Workshop and resulting 2024 publication, which called out some of the key discussion points and information gaps. One common sticking point is that the bucket of foods classified as UPF, specifically in the Nova scheme, is exceedingly broad, and refinement might better support guidance and messaging to limit foods with adverse effects on health.
In parallel with intervention studies of UPF are efforts to develop and apply new systems (e.g., Food Compass 2.0, FPro) or refine existing ones (Next Gen Nova). In this landscape, research and investment barrel ahead, while others are simultaneously evaluating and changing the very food classification schemes that are being tested.
Principles in the works
As a science-focused organization with the aim to support public health, IAFNS struggled to identify how our model of bringing together cross-sector scientists could add clarity to this debate. Yes, mechanistic data are needed and are in development. But, given that science is fundamentally the pursuit of truth, surely scientists of varying perspectives can align on some foundational elements.
To see if common ground can be found by focusing on fundamentals, IAFNS established a Working Group on Science-Based Principles for Food Classification Focused on Processing and Formulation to Support Public Health. The objective of this group is to identify simplified statements that scientists of varying perspectives can agree represent sound guidance, approaches or evidence that should be in place if one wants to classify foods based on processing or formulation characteristics – as relevant to health.
Examples of consensus statements (or “principles”) might be along the lines of “accepted scientific terminology should be used when classifying foods,” or “food processing is distinct from food formulation, which are measured differently.”
But what is the value of principles now that the train appears to have left the station? There are many definitions of a “principle,” but one that works here is “a fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning.”
Aligning activities with principles can ensure consistency, credibility, efficiency, focus and long-term success. Together, they create a stable framework. In terms of applicability to research, a few benefits of aligning on an agreed-upon set of principles include:
1. Ethical Integrity (Upholding honesty, transparency and fairness in data collection, analysis and reporting.)
2. Scientific Rigor (Ensuring methodological soundness to produce valid and reproducible results and minimizing bias through proper study design, controls and statistical analysis.)
3. Objectivity and Open-Mindedness (Minimizing or managing conflicts of interest or personal biases that could skew results and being willing to revise or reject hypotheses based on evidence.)
4. Transparency and Reproducibility (Clearly documenting methods, data and results so others can verify findings and encouraging open data sharing where appropriate.)
5. Social Responsibility and Relevance (Ensuring research addresses meaningful problems and benefits society and communicating findings responsibly to prevent misinformation.)
6. Collaboration and Respect (Promoting interdisciplinary cooperation and diverse perspectives and giving proper credit through citations and avoiding plagiarism.)
Where did this list come from? Modified from a ChatGPT query, it captures several needs for food classification research and application. In fact, many of these considerations have already been discussed by the IAFNS Principles Writing Team and will be reflected in the initial draft wording of the principles.
The value of principles for food classification
In an ideal world, these factors would be naturally “baked in” to any area of scientific investigation at the initiation of scientific exploration, but the reality is that subjectivity and interpretation have various entry points. In the area of food classification based on processing and formulation, the IAFNS Working Group sees value in level-setting the controversies by identifying statements of scientific truth that merit little debate across stakeholders.
These principles would be valuable for identifying where existing research aligns or may have strayed, designing new research with the principles as a benchmark, and/or in developing evidence-based policies insulated against unintended adverse consequences.
The principles in development will serve as a guidepost for the design, conduct and evaluation of research to support public health policy. They will evolve as the science evolves. IAFNS is soliciting input on the principles from the food and nutrition community at an April 15 public workshop. To register or give input, click here.
Will these science-based principles for food classification resolve global debates around highly or ultraprocessed foods? That’s not likely, nor is it the goal. However, they can serve as a reference point to advance research, policy and messaging in the direction of food classification based on processing and formulation that is truly meaningful for health.
Marie Latulippe, MS, MBA, RDN, is director of science programs at the Institute for the Advancement of Food & Nutrition Sciences, where she works with several nutrition committees, manages the board program committee and IAFNS Scientific Leadership Council.
