By Nina Gruber, ASU sustainable food systems graduate student
Model USDA’s first in-person convening brought students from 30 colleges and universities to Arizona State University to enact six real-world policy scenarios. Scenario A focused on the Dietary Guidelines for Americans (DGAs): should the next iteration address sustainability and ultra-processed foods (UPFs)?
The DGAs are developed through a multi-year scientific review process and translated into guidance by the USDA and HHS. They are not law, but they carry significant influence. They shape standards for school meals and other federal nutrition programs, guide public health messaging, and can influence labeling and market behavior. While the public encounters the Guidelines through headlines or dietary advice, their primary audience is policymakers and federal program administrators.
Model USDA is designed to test students’ ability to navigate competing interests under political and scientific uncertainty. Scenario A did exactly that. Participants were asked to grapple with two issues that are unsettled either scientifically or politically: defining ultra-processed foods and determining whether sustainability belongs in the DGAs at all. The central tension in the room was not whether health or sustainability matter, but whether the Guidelines are the appropriate medium to formalize them.
“Defining what sustainability is hasn’t been mentioned,” the student role-playing at HHS Secretary observed of the negotiations. The working group, made of students acting as representatives from both USDA and HHS, emphasized that formally including sustainability would require clear definitions, measurable indicators, and evidence linking those metrics directly to health outcomes. But because the stakeholders in the room were not able to meet these requests, a cautious workaround was proposed: sustainability would be “implicitly supported” through stronger emphasis on a whole food centric diet, rather than explicitly named.
Ultra-processed foods followed a similar path. “We are definitely concerned with ultra processed foods,” the student acting as HHS Secretary said, adding, “I do not have a personal definition.” The working group echoed that limitation and rather than define the category outright, the committee steered Americans toward “foods from whole sources” and away from ingredients “proven to harm human health,” referencing the NOVA classification system as a flexible framework rather than an enforceable standard.
In both cases, the absence of shared definitions became decisive. Without firm scientific metrics or clear legal permissions, participants gravitated toward language that was defensible but restrained. The safest consensus was to reinforce familiar nutrition guidance (prioritize whole foods and limit added sugars, sodium, and saturated fats) while avoiding directives that could provoke oversight concerns, market disruption, or unintended consequences for federal nutrition programs.
But even with just implicit mentions, Congressional critics argued that the DGAs are intended to address diet and health narrowly, not environmental sustainability, which would be outside the statutory scope under the 1990 National Nutrition Monitoring and Related Research Act. This threat was taken seriously by both the working group and stakeholders involved. Because the Guidelines influence SNAP, WIC, and school meal standards, even subtle wording shifts can have downstream effects on procurement, labeling, and agricultural markets. That reality loomed over negotiations.
Notably, sustainability-focused stakeholders ultimately accepted the compromise. While some initially pushed for more explicit recognition, many agreed that embedding sustainability implicitly within whole-food guidance was preferable to forcing a definition that might not survive political scrutiny. The mood in the room reflected an eagerness to agree rather than escalate. Coalition-building power was present, but rarely deployed to aggressively influence the working group.
The result was a set of recommendations that were difficult to oppose, and thus lacked the energy to initiate any transformative change. This outcome is not entirely out of character for the DGAs, which historically evolve incrementally. What felt distinct in this simulation was how visibly political constraints shaped the boundaries of scientific ambition.
Students acting as USDA and HHS officials acknowledged that sustainability may be critical to the future of the food system, but suggested the Dietary Guidelines may not be the right venue (at least for now) to define it formally. Ultra-processed foods, though widely recognized as a public health concern, remain conceptually unsettled in federal policy. With these limitations, the Guidelines advanced cautiously, reinforcing established nutrition goals while deferring more contentious structural questions.
For students, the exercise exposed a difficult tradeoff. Negotiation rewards common ground, and common ground often produces durable language, but this same result can dilute momentum. When scientific uncertainty meets statutory limits and political oversight, even ambitious conversations can land on safe and familiar grounds.
Model USDA demonstrated that the Dietary Guidelines are not only a scientific document but a political one. In this case, the safest bet prevailed: emphasize what is already widely accepted, avoid new definitions, and leave the most disruptive questions for another cycle.
This blog is part of a series written by Arizona State University (ASU) graduate students who role-played as journalists in Model USDA 2026, a multi-day simulation hosted by the Swette Center for Sustainable Food Systems at ASU.