California's ultra-processed food ban in schools faces implementation hurdles, study reveals

California aims to ban ultra-processed foods from school meals by 2035, but research shows budget, staffing, and infrastructure hurdles could impede progress, prompting calls for increased public investment.

California’s plan to remove ultra-processed foods from school meals is likely to improve children’s diets, but a new Stanford Medicine study suggests the policy will be far harder to deliver than to write.

The legislation, signed by Governor Gavin Newsom in October 2025, makes California the first US state to create a legal framework for phasing out certain ultra-processed foods from school menus. Public schools must begin the transition on July 1, 2029, and fully comply by July 1, 2035. The state Department of Public Health is due to define which products count as “ultra-processed foods of concern” and which foods will be restricted by June 1, 2028.

Stanford researchers found that school food service directors see budget pressure, staffing shortages, weak supply chains and limited kitchen infrastructure as the biggest obstacles to replacing heat-and-serve items with scratch-cooked meals. Andrea Pedroza-Tobias, the study’s lead author, said the change will require more public investment, arguing that for many California children school food is central to their daily nutrition. The research was published in Public Health Nutrition and drew on interviews with directors from 20 school districts in the San Joaquin Valley, where many families have low incomes and depend heavily on school meals.

The financial challenge is especially acute because ultra-processed products are often cheap, easy to store and simple to prepare with minimal equipment. California’s universal school meals programme, introduced in 2021, has increased participation and brought more money into district food service budgets, but the study says that may still not cover the higher cost of fresher ingredients. Amanda Harvey, nutrition services director for Fresno Unified School District, said even sourcing dye-free pickles could become difficult and expensive. Her district has also had to work around health department rules and kitchen limitations that make scratch cooking costly or impractical in many schools.

The study also points to a broader policy tension. School districts can sometimes lower costs by buying raw commodities through the US Department of Agriculture and having them processed into ready-to-serve items such as chicken nuggets, but that can leave menus more dependent on heavily processed food. Researchers said successful districts tend to combine extra funding with staff training, better kitchens and family engagement. One district even used a junior chef competition to help students shape the menu. Patel said the upfront cost may be worthwhile if healthier meals reduce later spending on obesity, type 2 diabetes and cardiovascular disease.