Thinking Public Health

The focus of this Thinking Public Health gathering is “Food in a MAHA era”

The Make America Healthy Again movement has placed food and diet at the center of national health discussion in ways not seen in decades. The 2025-30 Dietary Guidelines for Americans address ultra-processed foods (UPF) for the first time, and political figures across the spectrum have embraced the idea that what we eat is making us sick. Much of the current conversation focuses on ultra-processed foods — a category defined by the NOVA classification system — which now account for roughly half of caloric intake in the United States.

An umbrella review of nearly 10 million participants has linked high UPF consumption to elevated risks of cardiovascular disease, metabolic disorders, depression, and all-cause mortality, and a landmark randomized controlled trial demonstrated that subjects consuming an ultra-processed diet ate approximately 500 more calories per day and gained weight, even when meals were matched for macronutrients, sugar, sodium, and fiber. A three-paper Lancet Series published in late 2025 synthesized the evidence and called for systemic policy action — not consumer education — as the primary lever of change.

This is where the tension lies. There is a familiar and, frankly, frustrating impulse in public health to treat awareness as intervention: If only people knew that half their diets consisted of ultra-processed foods, they would change their behavior. But we have never been able to educate our way out of tobacco, alcohol, obesity, or any other population-level health challenge, and it is misguided to place the burden of dietary change on individuals without altering the structural conditions — food environments, agricultural subsidies, corporate marketing practices — that make ultra-processed foods the default. It is reasonable to worry that the current enthusiasm for UPFs as a category risks becoming the shiny new object in nutrition science, distracting from the policy and systems changes that the evidence has supported for years.

In the background — acknowledged but largely unaddressed in this conversation — sits the enormous influence of the food industry in shaping what we eat, how it is marketed, and how policy is made. How should public health engage with the current political energy around food? Is the UPF framing a genuinely useful addition to our policy toolkit, or does it risk recapitulating the same cycles of awareness without action? And what would meaningful structural change actually look like?

Pre-reads

Hall KD, Ayuketah A, Brychta R, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab. 2019;30(1):67-77.e3. doi:10.1016/j.cmet.2019.05.008

Lane MM, Gamage E, Du S, et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024;384:e077310. doi:10.1136/bmj-2023-077310

Monteiro CA, Louzada MLC, Steele-Martinez E, et al. Ultra-processed foods and human health: the main thesis and the evidence. Lancet. 2025;406(10520):2667-2684. doi:10.1016/S0140-6736(25)01565-X

Scrinis G, Popkin BM, Corvalán C, et al. Policies to halt and reverse the rise in ultra-processed food production, marketing, and consumption. Lancet. 2025;406(10520):2685-2702. doi:10.1016/S0140-6736(25)01566-1

Baker P, Slater S, White M, et al. Towards unified global action on ultra-processed foods: understanding commercial determinants, countering corporate power, and mobilising a public health response. Lancet. 2025;406(10520):2703-2726. doi:10.1016/S0140-6736(25)01567-3

Thinking Public Health is a monthly, in-person gathering for moderated, structured conversations on pressing public health topics. Held under the Chatham House Rule, these discussions encourage open dialogue within the WashU Public Health community.