• Posted May 21, 2025

Blood, Urine Tests Can Identify Level Of Ultra-Processed Food In Diet

Worried you’re scarfing down too many ultra-processed foods?

Blood and urine tests might be able to reveal how much of your diet is made up of industrially produced foods, a new study says.

Chemicals produced as the body converts ultra-processed food and drink into energy can be found in people’s blood and urine, researchers reported May 20 in the journal PLOS Medicine.

Certain sets of these chemicals, known as metabolites, reliably correspond with how much ultra-processed food a person is eating, researchers found.

Scores based on these metabolites, “predictive of ultra-processed food intake, could provide novel insight into the role of ultra-processed food in human health,” wrote a team led by senior researcher Erikka Loftfield, an investigator of metabolic epidemiology with the National Cancer Institute. 

Ultra-processed foods are made mostly from substances extracted from whole foods, like saturated fats, starches and added sugars.

These products also contain a wide variety of additives to make them more tasty, attractive and shelf-stable, including colors, emulsifiers, flavors and stabilizers.

Examples include packaged baked goods, sugary cereals, ready-to-eat or ready-to-heat products and deli meat.

Mounting evidence has linked ultra-processed foods to a number of health risks.

For example, an April study found that for each 10% increase in ultra-processed foods, a person’s risk of early death from any cause rises by 3%, according to findings published in the American Journal of Preventive Medicine.

Ultra-processed foods now account for more than half the calories consumed by adults and children in the U.S., researchers said in background notes.

For this new study, researchers analyzed blood and urine samples from 718 older adults, alongside food diaries, to identify metabolites linked to ultra-processed foods. This process took a year, with participants providing blood samples at the beginning, middle and end of the year.

Overall, researchers identified 191 metabolites in blood and nearly 300 in urine significantly correlated with ultra-processed food intake, researchers said.

From those, they selected 28 metabolites in blood and 33 metabolites in urine to serve as a more precise “score” for evaluating how much ultra-processed food a person had eaten.

The researchers then tested their findings in a lab experiment by feeding 20 people two different diets, one containing 80% ultra-processed foods and the other no ultra-processed eats at all.

Each person ate each diet for two weeks, after which blood and urine samples were taken.

Results showed that the identified metabolites did indeed track with the amounts of ultra-processed food that the lab participants had devoured over the previous two weeks.

A smaller group of four people showed that the tests also could tell apart diets containing 30% and 80% ultra-processed foods.

These sort of tests could provide a serious boost to efforts aimed at understanding the impact of ultra-processed foods on a person’s health, researchers said.

Using the tests, researchers wouldn’t have to rely on people’s recall to determine how much ultra-processed food they’ve eaten.

“The metabolomic profiles we identified reflect a dietary pattern characterized not only by high ultra-processed food consumption but also by low intake of whole foods, including fresh fruits and vegetables,” the researchers wrote.

However, they noted that their tests need to be confirmed in larger studies involving more people from different backgrounds eating varying diets.

More information

The Cleveland Clinic has more on ultra-processed foods.

SOURCES: PLOS Medicine, May 20, 2025; PLOS, news release, May 20, 2025