Many ultraprocessed foods are high in added sugars, sodium or saturated fat. That has long made it difficult to answer a deceptively simple question: Are these foods associated with poorer health mainly because of what is in them, or could the way they are made also matter?
A new observational study suggests nutrition labels may not capture the entire picture. Researchers found that people who ate more ultraprocessed food tended to have worse cardiometabolic health and a slightly higher risk of dying during the study period, even after the researchers accounted for overall diet quality and the amounts of saturated fat, added sugar and sodium in the foods they reported eating.
The findings do not prove that industrial processing caused those health differences. They also do not show that every packaged food carries the same risks or identify which specific manufacturing methods, additives or packaging-related exposures may matter most. Instead, the study adds to a growing debate over whether traditional nutrition metrics are enough to evaluate the health effects of modern food products.
The observational study was published in the American Journal of Public Health. Its senior author, Dariush Mozaffarian, a cardiologist and director of the Food is Medicine Institute at Tufts University, reported research funding, advisory roles, consulting work and equity interests involving several health-related organizations and companies. The full conflict-of-interest disclosure is available with the published study.
Researchers analyzed data from 10 consecutive cycles of the National Health and Nutrition Examination Survey, or NHANES, from 1999 to 2018. The nationally representative survey collects information about the health and eating habits of people in the United States. Participants in this study completed one or two 24-hour dietary recalls describing what they had eaten.
The researchers grouped foods according to how they were made, ranging from minimally processed foods such as fruits and vegetables to ultraprocessed products made with industrial ingredients or additives not typically used in home cooking. They also assigned participants an overall diet-quality score based on the foods they reported eating.
The team then examined how the percentage of calories coming from ultraprocessed food was associated with measures such as body weight, blood sugar, blood pressure and cholesterol. They also looked at diagnoses including diabetes and metabolic syndrome and linked participants’ records to mortality data through 2018.
For every 10% increase in calories from ultraprocessed food, the researchers found less favorable health markers. People who ate more of these foods tended to have higher body weight, poorer blood sugar control, higher blood pressure and less favorable cholesterol levels. They were also more likely to have certain health conditions and had a slightly higher risk of dying during the study period.
The associations remained even after the researchers adjusted for overall diet quality and the amounts of saturated fat, added sugar and sodium in the ultraprocessed foods participants reported eating.
That does not mean the study isolated a single explanation. People who eat more ultraprocessed food may differ from people who eat less of it in ways researchers cannot fully capture. The study also relied on dietary recalls, which provide useful information but depend on participants accurately remembering what they ate.
Still, the findings raise a meaningful question. Researchers have proposed several possible reasons the level of processing might matter, including changes to a food’s physical structure, the loss of certain beneficial compounds, the use of additives and exposure to chemicals from packaging. This study did not test those mechanisms directly.
Mozaffarian said the findings suggest factors beyond nutrients “may create health risks not addressed by traditional nutrition metrics or policies.”
The term ultraprocessed food covers a broad range of products, and that can make the conversation confusing. A sugary drink, a packaged snack and a convenience food that helps someone put dinner on the table may all fall into the same broad category, even though their nutritional value and role in a person’s diet can differ considerably.
For most people, the practical takeaway is not to panic about every item in a box, bag or wrapper. It is to look at the overall balance of the diet. When realistic, choosing more fruits, vegetables, beans, whole grains, nuts and other minimally processed foods can be a useful goal. Packaged foods can still have a place, especially when affordability, time, access or convenience are important.
Scientists are still working to understand which types of ultraprocessed foods deserve the most concern and whether particular ingredients or manufacturing methods carry meaningful risks. This study does not settle that debate. It does suggest the nutrition label may be only one part of the story.
The research was supported by the National Heart, Lung, and Blood Institute, an American Diabetes Association Pathway to Stop Diabetes award and the Laidlaw Foundation’s Laidlaw Scholars Leadership & Research Programme.