Can Blood and Urine Reveal How Much Ultra-Processed Food You Really Eat? Study Sheds Light

New Delhi: A new study published in the open-access journal PLOS Medicine has identified specific chemical signatures in blood and urine that reliably reflect how much ultra-processed food (UPF) a person consumes. Conducted by Erikka Loftfield and colleagues at the National Cancer Institute, USA, the research offers a new tool for objectively measuring ultra-processed food intake, which has been linked to various chronic diseases.

The study analyzed biological samples from 718 older adults, alongside detailed self-reported dietary data. Researchers identified a wide range of metabolites—small molecules produced during digestion and metabolism—that were closely associated with the proportion of energy participants derived from ultra-processed foods.

Using this data, the team developed a “poly-metabolite score,” a chemical profile that serves as a biomarker for ultra-processed food consumption. This score could be calculated using a combination of 28 blood metabolites or 33 urine metabolites. The researchers found that these scores accurately reflected the participants' reported ultra-processed food intake levels.

To validate their findings, the team conducted a tightly controlled feeding study at the NIH Clinical Center. Twenty inpatients were provided with diets either rich in or free of ultra-processed food. The metabolite scores were able to clearly distinguish between high- ultra-processed food and no- ultra-processed food diets within the same individuals, demonstrating the reliability of these biomarkers in real-world dietary conditions.

"The identified poly-metabolite scores could serve as objective measures of ultra-processed food intake in large population studies to complement or reduce reliance on self-reported dietary data," the authors say.

"Poly-metabolite scores should be evaluated and iteratively improved in populations with diverse diets and a wide range of ultra-processed food intake."

The authors add, "We developed and tested poly-metabolite scores in blood and urine that were predictive of diets high in energy from ultra-processed food intake in an observational study of free-living adults and in a highly controlled feeding trial, respectively. These poly-metabolite scores could serve as objective measures of ultra-processed food intake in large population studies to complement or reduce reliance on self-reported dietary data. Additionally, these findings could provide novel insight into the role of ultra-processed food in human health."

Reference: Leila Abar, Eurídice Martínez Steele, Sang Kyu Lee, Lisa Kahle, Steven C. Moore, Eleanor Watts, Caitlin P. O’Connell, Charles E. Matthews, Kirsten A. Herrick, Kevin D. Hall, Lauren E. O’Connor, Neal D. Freedman, Rashmi Sinha, Hyokyoung G. Hong, Erikka Loftfield. Identification and validation of poly-metabolite scores for diets high in ultra-processed food: An observational study and post-hoc randomized controlled crossover-feeding trial. PLOS Medicine, 2025; 22 (5): e1004560 DOI: 10.1371/journal.pmed.1004560