By Marie Latulippe of Institute for the Advancement of Food & Nutrition Sciences

Food policy is consistently in the headlines. New government dietary guidance was just released, and it cautions against processed foods. A federal Request for Information on defining ultraprocessed foods was issued in 2025. These events highlight how the food and nutrition ecosystem is central to many major federal decisions.

In April of 2025, IAFNS described an effort to ensure that classification of foods by processing and formulation is science-based. The final result is a Set of 9 Guiding Principles for Food Classification Focused on Processing and Formulation.

The principles paper is the culmination of several working meetings, a public workshop and additional refinement – and is now available open-access in the peer-reviewed journal Advances in Nutrition. These principles were drafted by a writing team of public sector scientists with diverse expertise and experience with the complexities and nuance of the topic.

Given the writing team involved, the principles are geared to some extent to the research community. Many of the principles promote clear scientific thinking and analysis. However, IAFNS recognizes that conversations around food classification, processing and formulation span many population segments and sectors. So, thinking about the principles in a more concrete way may be useful.

For example, consider the full wording of Principle 9: “The probative value of a research question or proposed food classification system should be considered prior to engaging in analysis or development.” In other words, does the proposed research add to what we know?

Or, Principle 3: “Associations without robust causal evidence should be considered preliminary,” as major food decisions would benefit from randomized controlled trial data. To assist stakeholders, IAFNS offers a translated wording of all nine principles on the IAFNS website.

Here are a few examples of how one might leverage the principles for specific decision-making. The first relates to Principle 1: “Documentation and definitions that allow for reproducibility, rigor and transparency should be provided.” This was called out by the 2025-2030 US Dietary Guidelines Advisory Committee. That body categorized the evidence on dietary patterns with processed foods and weight-gain as “limited” because ultraprocessed foods lack definition.

As another example, Principle 4 states: “The impact that processing steps have on the final composition and structure of the food in terms of a putative effect on a health-related endpoint should be considered.” Although food classification systems purportedly consider “processing level,” a single type of processing can be used to create foods with very different nutrient profiles. For example, the processing method of extrusion creates a variety of foods ranging from fiber-rich cereal to puffed snacks. And cold-pressed juicing can preserve nutrients longer when refrigerated than using more traditional methods.

A science-based approach aligned with Principle 4 would consider each processing step, how it changes a food, and how that change impacts human health. This would ensure that food classification efforts have integrity and are internally consistent.

Admittedly, to a degree, the principles are aspirational. It may not be possible to align them with all research questions and other applications, at least currently. The focus of the principles is on key aspects of sound conceptual development and scientific evidence. The objective here is to set a high bar for science to prevent an ill-informed rush to judgment and avoid adverse public health outcomes.

The principles highlight that we may have more questions than answers at this point. Users of the principles would need to decide when the gaps preclude decision-making and when there might be adequate information to move forward. For example, we have authoritative safety evaluations and approval of many food additives that consider the form used in food, the level of intake given approved uses in foods and the toxicological profile. When evaluating health impact, the intersection of processing and formulation brings even more opportunities for investigation.

Taking a pause may allow managers, administrators and researchers time to consider evidence gaps that, once filled, would shift the decision landscape. The more information and data the better decision-makers can do their job.

Users of the principles would decide when there is sufficient new information to move forward – with study design, a specific food classification scheme or a policy decision. In this way it is hoped the nine principles can support decision-making by researchers, policymakers and the public.