Plate Nº 14 · recorded October 10, 2026
Health & Medicine ResearchReported finding
Identical Labels, Different Bodies: Processing Alone Changes Metabolism
Meals matched within 1% on every nutrient label still triggered higher insulin and different brain reward responses, a Virginia Tech team reports in Nature Metabolism.
By Priya Raman3 min read648 words
In brief
- Virginia Tech researchers published the findings Oct. 5 in Nature Metabolism.
- Test meals were matched within 1% for carbs, fat, protein, calories, water and salt.
- The ultraprocessed 300-calorie meal triggered higher insulin and longer-elevated blood sugar.
- 57 healthy adults participated; 32 completed both brain fMRI and metabolic sessions.
- Ultraprocessed foods supply more than half of the average American's daily calories.
Two meals matched within 1% for calories, carbs, fat, protein, water and salt produced measurably different metabolic and brain responses in the same people, according to a Virginia Tech study published Oct. 5 in Nature Metabolism.
The 300-calorie ultraprocessed meal made participants release more insulin, burn more energy overall, and use less carbohydrate for fuel than a nutritionally identical minimally processed meal. It also evoked different responses in brain regions tied to motivation and reward.
"We were shocked when every single metabolic metric differed," said Zach Hutelin, the study's first author, who completed the research as part of his doctoral work in Virginia Tech's Translational Biology, Medicine, and Health Graduate Program.
Why did researchers test this?
Ultraprocessed foods make up more than half of the average American's daily calories, and diets worldwide are shifting in the same direction. Population studies link heavy consumption to obesity, cardiac events, type 2 diabetes and even some measures of mental health, according to Alex DiFeliceantonio, an associate professor at the Fralin Biomedical Research Institute at VTC whose lab led the work.
But those foods are typically high in fat and sugar and low in fiber and protein — so it has been hard to separate the effect of processing from the effect of nutrients.
"If we artificially hold all of those things constant, is there something about the processing that leads to a different outcome?" DiFeliceantonio asked.
How was the study run?
The researchers recruited 57 healthy adults aged 18 to 45; 32 of them completed both brain imaging and metabolic testing sessions. Each participant ate both meal types in separate sessions at least three days apart, letting the team compare each person against themselves.
After an overnight fast, participants entered a metabolic chamber — a sealed, airtight room that measures energy expenditure. They had 10 minutes to eat one of the meals, chosen using the NOVA scale, which sorts foods into four groups by degree of industrial processing:
- The highly processed meal: peanut butter and jelly sandwich, deli turkey, veggie chips, a cookie, cereal, instant mashed potatoes and water.
- The minimally processed meal: sliced banana, dried cranberries, cheese and egg.
"If these meals had a nutritional label, they would be practically identical," Hutelin said.
Researchers drew blood immediately after eating and six more times over three hours, measuring insulin response, energy expenditure and carbohydrate oxidation — how much carbohydrate the body burns for fuel.
The ultraprocessed meal drove a much higher insulin response, and blood sugar stayed somewhat higher for somewhat longer. Chronically elevated blood sugar raises the risk of conditions such as diabetes.
What happened in the brain?
On a separate day, participants viewed pictures of nutritionally matched processed and unprocessed foods inside a functional MRI scanner, which tracks brain activity through changes in blood flow. While viewing each food, they reported how much they would pay for it.
Differences in how participants burned carbohydrates after each meal were linked to differences in activity in the ventral striatum and nucleus accumbens — brain regions involved in learning, motivation and reward. Participants did not say they would pay more for either food type, but the metabolic differences tracked with brain responses to food cues.
Carlos A. Monteiro of the University of São Paulo, the epidemiologist who developed the NOVA classification, told Nature Metabolism that the study adds a novel layer: "The brain ultimately regulates eating behavior."
What are the limits?
The findings are preliminary and come with caveats. The study tested a single set of 300-calorie meals in young, healthy adults. Protein sources differed between meals, which could have influenced the results, and the ultraprocessed meal contained more additives. The team did not measure the physical and chemical structure of the foods.
DiFeliceantonio wants to test larger meals, longer time periods, more food pairings and different populations, and to pinpoint specific additives or processing steps that might drive the responses.
via Medical Xpress (Source)
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Senior reporter covering industry trends and analytics at SciBeat.
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