Quick blood test can now show exactly how much ultra-processed junk food a person eats

More than half of the average American’s daily calories come from ultra-processed food (UPF). A new score helps measure how much of this food people actually eat, even though they may be unaware of it.

A new investigation guided by Dr. Erikka Loftfield at the National Cancer Institute identifies tiny molecules in blood and urine that seem to line up with how many of these ultra-processed food products a person eats.

Researchers found that certain metabolite patterns, called poly-metabolite scores, could help scientists check the accuracy of self-reported diets.

A food score helps track hidden intake

Many people have no idea how much ultra-processed food they actually consume. Even well-intentioned eaters might miss hidden additives, processed oils, or preservatives in everyday meals.

This new testing method offers a way to cut through the confusion. It gives researchers – and potentially doctors – a snapshot of your diet without needing you to log every bite.

Tracking complex eating habits

Individuals might overlook many items that fit into ultra-processed categories. Instant noodles, sweet packaged snacks, and store-bought pastries often fly under the radar.

The research team developed an approach to measure small chemical markers in blood and urine. They used a set of older participants who had provided detailed dietary reports across 12 months.

These markers were linked to how often a person consumed ultra-processed items. They looked like a fingerprint that matched the share of daily calories coming from those foods.

Some ultra-processed items carry more salt, sugar, and artificial flavors than simpler choices. These features can make them attractive and shelf-stable but also raise questions about long-term health effects.

Investigators combined both diet records and lab data to improve accuracy. This kind of measurement could catch missed details when people forget what they ate.

Score reveals true junk food levels

The team created a score that reflected this chemical signature. They tested the score on volunteers in a highly controlled inpatient setting to confirm that it worked.

“The identified poly-metabolite scores could serve as objective measures of UPF intake in large population studies to complement or reduce reliance on self-reported dietary data.

Poly-metabolite scores should be evaluated and iteratively improved in populations with diverse diets and a wide range of UPF intake,” added Dr. Loftfield. 

The new score might reduce guesswork in nutrition studies. Each type of marker may hold clues about processed ingredients that might not appear in fresh or minimally processed foods.

Doctors may check diet with a test

In the future, your doctor might learn more from a urine test than from a food diary. If these metabolite scores become widely available, clinicians could use them to flag poor dietary patterns without needing long conversations or guesswork.

This could speed up diagnosis and allow earlier interventions for diet-related issues. It also opens the door for personalized nutrition advice, built on real chemical data rather than rough estimates.

Impact of ultra-processed foods

Experts continue to investigate whether these products affect weight and disease risk. Some evidence shows that heavy intake of such foods can coincide with weight gain.

Advanced glycation compounds formed in some food processes might play a role in metabolic conditions. Researchers hope that pinpointing these markers may offer new insights.

Score exposes what brands don’t highlight

Food manufacturers often use marketing to frame ultra-processed products as convenient or fortified with nutrients.

But the presence of these chemical signatures in blood and urine paints a different picture, one that links these foods to measurable biological changes.

As researchers get closer to pinpointing how these products affect the body, companies could face growing pressure to reformulate their offerings.

If specific ingredients or production methods are consistently tied to the presence of harmful markers, regulators might push for transparency or even restrictions.

How the food score improves tracking

Many people rely on memory when telling doctors or researchers what they ate.

This score could someday serve as a helpful backup by offering an objective way to see whether someone’s reported consumption lines up with their actual exposure.

Scientists expect that future research may refine these measures for broader use. More diverse samples, including younger individuals and different cultural diets, could increase the reliability of these findings.

Taking a closer look at blood and urine has sparked new ideas about how to identify ultra-processed food intake.

Implications for future health policies

Public health agencies could eventually use these poly-metabolite scores to improve large-scale nutrition surveillance.

Instead of relying only on self-reports or food purchase data, officials might turn to biochemical evidence to track dietary trends across regions or demographics.

Insurance companies or employers may also show interest in using these biomarkers to assess dietary risks. While this raises ethical questions, it reflects a growing push to personalize prevention strategies based on measurable health behaviors.

The study is published in PLOS Medicine.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–