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SATURDAY, SEPTEMBER 19, 2026
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What the New Study on Ultra Processed Food Actually Found

A study of 20,000 adults over eight years links high ultra-processed food intake to a 15 percent higher rate of early death, but the design cannot prove the food itself is the cause.

By Eli Okafor, Health & Wellness

· 2 min read

Key Takeaways

  • •A study of 20,000 adults over 8 years found a 15 percent higher all-cause mortality rate in the highest ultra-processed food intake group.
  • •The study is observational and cannot prove the food itself causes the higher death rate.
  • •Results were adjusted for BMI, smoking, activity level, and existing diabetes or cardiovascular disease, but not income or sleep quality.
  • •The association has now been replicated across at least four major cohort studies since 2019.

A study published September 4 in the journal JAMA Internal Medicine followed 20,000 adults for an average of eight years and found that people whose diets were more than 60 percent ultra-processed food by caloric intake had a 15 percent higher rate of death from any cause than those below 20 percent, even after adjusting for weight, smoking, and existing health conditions.

This is an observational study, not a controlled trial, which matters. Here is what that distinction actually means and what the study can and cannot tell you.

What is actually known versus what is still being studied

The Short Answer

The study found a statistical association between high ultra-processed food intake and higher mortality risk over eight years, adjusted for major known confounders. It cannot prove ultra-processed food itself causes early death, because people who eat more of it may differ from other groups in ways the study could not fully measure, like income, sleep, or stress levels.

The researchers defined ultra-processed using the NOVA classification system, a four-tier framework created by Brazilian researchers in 2009 that is now standard in nutrition research. It includes packaged snacks, sodas, most breakfast cereals, and reconstituted meat products, but excludes minimally processed foods like canned vegetables or plain yogurt.

15%

higher all-cause mortality rate in the highest ultra-processed food intake group

Based on 20,000 participants tracked over an average of 8 years, published in JAMA Internal Medicine, September 4, 2026.

The study adjusted its results for body mass index, smoking status, physical activity, and pre-existing diabetes or cardiovascular disease, which is more rigorous than many earlier studies on this topic. It did not adjust for household income or sleep quality, both of which independently correlate with diet quality and mortality risk.

“An association this size, after this many adjustments, over an eight-year follow-up, is a meaningfully stronger signal than most nutrition headlines you will see. It is still not the same thing as a randomized trial proving cause and effect, and it would be dishonest to say otherwise.”

Dr. Amara Fields, epidemiologist, not affiliated with the study, quoted via email

Bottom line

Solid evidence: high ultra-processed food intake is associated with higher mortality risk in large, well-adjusted observational studies, and this pattern has now been replicated across at least four major cohort studies since 2019. Still being studied: whether the effect comes from the processing itself, from the nutrients these foods typically lack, like fiber, or from unmeasured lifestyle factors common among people who eat more of them.

For a reader deciding what to do with this information, the practical takeaway is not that ultra-processed food is proven to shorten your life on its own, but that reducing it, whatever the exact mechanism, sits on the more solid end of current nutrition evidence, alongside things like regular physical activity and adequate sleep.

Frequently Asked Questions

Does this study prove ultra-processed food causes early death?
No. It is an observational study showing a statistical association after adjusting for several known risk factors. It cannot rule out that other unmeasured factors contribute to the difference.
What counts as ultra-processed food?
The study used the NOVA classification, which includes packaged snacks, sodas, most breakfast cereals, and reconstituted meat products. It excludes minimally processed foods like canned vegetables or plain yogurt.
  • nutrition
  • public health
  • ultra-processed food
  • epidemiology

Sources

  1. 01Ultra-Processed Food Intake and Long-Term Mortality Risk, JAMA Internal Medicineexample.com
  2. 02NOVA Food Classification System, University of São Paulo Center for Epidemiological Studies in Health and Nutritionexample.com

Corrections

No corrections have been made to this article.

About the reporter

Eli Okafor

Health & Wellness Reporter, Trestlewire

I come from a health-policy and medical-reporting background. I want to be clear about one thing up front: I am not a physician, and nothing I write is medical advice. My job is to report on health accurately, not to practice it.

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