America’s ultra-processed food industry is beginning to face a new category of litigation that could eventually resemble earlier lawsuits involving tobacco, opioids and other consumer products. Plaintiffs are arguing that major food manufacturers deliberately designed highly processed products to encourage overconsumption while failing to adequately disclose possible long-term health risks.
Companies including Kraft Heinz, Coca-Cola, PepsiCo, Mondelez, General Mills, Nestlé, Mars and Conagra have already been named in major cases. However, this litigation remains relatively new, and courts have shown that proving a direct connection between particular foods and an individual’s disease will be a major legal hurdle.
San Francisco Files Landmark Ultra-Processed Food Lawsuit
The biggest government case began on December 2, 2025, when San Francisco City Attorney David Chiu filed a lawsuit on behalf of the People of California against major food and beverage manufacturers.
Defendants named in the complaint include Kraft Heinz, Mondelez International, Post Holdings, Coca-Cola, PepsiCo, General Mills, Nestlé USA, Kellanova, WK Kellogg, Mars and Conagra Brands.
The lawsuit alleges that the companies developed and aggressively marketed ultra-processed foods while knowing that heavy consumption was associated with serious health problems.
San Francisco specifically accuses the industry of designing foods to encourage repeated consumption and using marketing strategies directed at children and vulnerable communities.
The complaint draws comparisons with tactics historically associated with the tobacco industry, although those comparisons remain allegations that must be proved in court.
What San Francisco Is Seeking
The city’s lawsuit is based primarily on California’s Unfair Competition Law and public-nuisance law.
San Francisco argues that diseases allegedly associated with heavy consumption of ultra-processed foods have increased healthcare and other public costs.
The lawsuit seeks measures including:
- Civil penalties
- Injunctions against allegedly deceptive business practices
- Corrective measures concerning marketing
- Costs associated with addressing the alleged public nuisance
The city is not simply seeking compensation for individual consumers. It is attempting to hold manufacturers responsible for broader public-health costs allegedly connected with their products.
Food Companies Tried to Move the Case to Federal Court
The defendants removed the San Francisco lawsuit from California state court to the U.S. District Court for the Northern District of California.
San Francisco asked for the case to be returned to state court.
On April 23, 2026, U.S. District Judge Jon S. Tigar granted the city’s request and remanded the lawsuit back to California state court. The decision concerned jurisdiction rather than whether ultra-processed foods actually caused the diseases alleged in the complaint.
As of September 2026, the underlying case remains an important pending test of whether public-nuisance and consumer-protection laws can be successfully applied to the ultra-processed food industry.
Martinez v. Kraft Heinz and Other Food Companies
The first major individual personal-injury lawsuit produced a very different result.
Bryce Martinez filed suit against 11 major food companies after alleging that years of consuming ultra-processed foods contributed to his development of Type 2 diabetes and non-alcoholic fatty liver disease when he was 16.
The defendants included Kraft Heinz, Mondelez, Post Holdings, Coca-Cola, PepsiCo, General Mills, Nestlé, Kellanova, WK Kellogg, Mars and Conagra.
Martinez alleged that manufacturers intentionally produced highly palatable and potentially addictive foods, aggressively marketed them to children and failed to warn consumers about health risks.
His claims included negligence, failure to warn, breach of warranty, misrepresentation, fraudulent concealment and consumer-protection allegations.
Federal Court Rejects the Martinez Claims
The lawsuit encountered a major problem: causation.
In August 2025, U.S. District Judge Mia Roberts Perez dismissed the original complaint, finding that it failed to sufficiently explain which particular products caused Martinez’s diseases and how.
Martinez then proposed a much more detailed amended complaint identifying 179 products he said he had consumed.
Even that was not enough.
On June 30, 2026, the court refused permission to file the amended complaint. Judge Perez explained that showing a general correlation between increased ultra-processed food consumption and increased rates of diseases such as Type 2 diabetes does not establish that particular products caused a particular plaintiff’s illness.
The court said Pennsylvania law required specific causation rather than a broad industry-wide theory.
The ruling represented an important early victory for food manufacturers.
Why Causation Is the Biggest Problem for UPF Lawsuits
Ultra-processed food litigation faces a difficult legal question that tobacco litigation did not always face in the same form.
Most consumers eat thousands of different foods over many years. Obesity, diabetes, cardiovascular disease and fatty liver disease can also involve genetics, lifestyle, overall diet, physical activity and other factors.
A plaintiff may therefore have to prove not merely that ultra-processed foods can increase disease risk but that specific products manufactured by specific defendants substantially caused the plaintiff’s particular illness.
The Martinez decision shows courts may reject claims that simply treat the entire food industry as jointly responsible.
Are Ultra-Processed Food Lawsuits Becoming a Mass Tort?
There is currently no nationwide ultra-processed food multidistrict litigation comparable to major pharmaceutical, asbestos or Roundup litigation.
The lawsuits are still at an early stage.
The Martinez case demonstrated how difficult individual injury claims can be, while San Francisco is testing a different approach based on public nuisance and consumer-protection laws rather than attempting to prove that particular products caused one person’s disease.
The outcome of the San Francisco case may therefore be especially important. If the city succeeds in keeping substantial claims alive, other cities, states and private plaintiffs could attempt similar lawsuits. If food manufacturers obtain an early dismissal, it could significantly slow the developing litigation.
For now, the ultra-processed food industry is facing a genuine new legal challenge, but there has been no court ruling establishing that major manufacturers are broadly liable for chronic diseases associated with consumption of ultra-processed foods.
