TL;DR
Get workout gear delivered free with Prime
- Fast, free delivery on millions of items
- Prime Video, Amazon Music and more included
- Member-only deals all year
Virginia Tech researchers report that healthy adults responded differently to highly processed and minimally processed meals matched for calories and major nutrients. The findings also linked differences in carbohydrate use with brain responses to food images, but do not establish that processing causes long-term illness or overeating.
Virginia Tech researchers found that healthy adults had different metabolic responses after eating highly processed and minimally processed meals matched for calories and key nutrients, with related differences in brain activity when participants viewed food images. Published in Nature Metabolism in October 2026, the study suggests that processing may shape the body’s and brain’s responses beyond the meals’ measured nutritional profiles, though it does not show that processing causes long-term health problems.
The study included 57 healthy adults aged 18 to 45. Each participant ate both types of meal in separate sessions at least three days apart, allowing researchers to compare responses within the same person. The meals were matched to within 1 percent for calories, carbohydrates, fat, protein, water, salt and weight.
For the metabolic sessions, participants fasted overnight and ate a 300-calorie meal in 10 minutes. The highly processed selection included small portions of a peanut butter and jelly sandwich, deli turkey, vegetable chips, a cookie, cereal and instant mashed potatoes. The minimally processed selection included banana, dried cranberries, cheese and egg. Researchers collected blood samples after eating and tracked metabolism for three hours in a sealed chamber that measures energy expenditure.
The researchers reported higher insulin responses and somewhat longer-lasting elevations in blood sugar after the highly processed meal. Participants also expended more energy and burned less carbohydrate for fuel after that meal. In a separate session, 32 participants completed both the metabolic and brain-imaging tests. Functional MRI scans showed differences in responses to food pictures in the ventral striatum and nucleus accumbens, brain areas involved in learning, motivation and reward. Differences in carbohydrate use were linked with differences in those brain responses. Participants did not report being willing to pay more for either category of food.
Processing May Shape More Than Nutrients
The findings address a question in nutrition research: whether the degree of food processing matters when measured nutrients are held nearly constant. The observed differences suggest that calories and major nutrients alone may not capture every short-term response to a meal. Linking metabolic measures with brain responses also offers researchers a way to investigate how the body’s handling of food relates to responses to food cues.
That question matters because ultraprocessed foods make up more than half of the average American’s daily calories, according to the report, and their share of diets is increasing globally. The researchers say these products are often designed for convenience, affordability and palatability, and may be easy to overeat. But this experiment measured short-term responses to specific meals; it did not test eating behavior over time or establish that processing itself causes disease.
Population studies have associated high consumption of ultraprocessed foods with poor health outcomes, including obesity, cardiovascular events and Type 2 diabetes. Those associations do not, by themselves, identify the mechanism or prove cause and effect. The new findings provide one possible avenue for further study, not a basis for concluding that a single meal will produce lasting harm.
As an affiliate, we earn on qualifying purchases.
How Researchers Matched the Meals
Many ultraprocessed foods differ from less processed foods in several ways at once, including levels of sugar, fat, fiber and protein. That makes it difficult to determine whether observed health associations stem from processing, nutritional composition, eating patterns or other factors. The Virginia Tech team designed its comparison to hold several nutritional measures nearly constant while varying the meals’ processing category.
Researchers classified foods using the Nova scale, which groups foods according to their level of industrial processing. The study then combined two kinds of testing: measurements of blood and energy use after eating, and functional MRI scans while participants viewed food images. The imaging session also asked participants how much they would be willing to pay for each pictured food; reported willingness to pay did not differ between the two categories.
The work was led by a team at the Fralin Biomedical Research Institute at VTC. Alex DiFeliceantonio, an associate professor at the institute, leads the lab; Zach Hutelin, the study’s first author, conducted the work as part of his doctoral research in Virginia Tech’s Translational Biology, Medicine, and Health Graduate Program.
“If you look at that population-level data, people who consume large amounts of ultraprocessed foods have higher rates of poor health outcomes — obesity, cardiac events, Type 2 diabetes, and even some metrics of mental health.”
— Alex DiFeliceantonio, Fralin Biomedical Research Institute associate professor
Long-Term Effects Remain Unknown
The experiment involved a small group of healthy adults and measured responses over hours, not long-term health or usual eating habits. It cannot determine whether the differences persist with repeated consumption, affect people with different health profiles, or lead to changes in food intake or disease risk.
The study also does not identify which aspects of processing account for the results. Matching meals for calories and several nutrients reduces some differences, but the foods still vary in their ingredients and physical characteristics. The reported link between carbohydrate burning and brain responses is an association within the study, not proof that one response caused the other. The supplied report does not provide further details on the size of every effect or on additional research plans.
Further Tests Needed to Explain Differences
The published findings give researchers a basis for follow-up studies, but the report does not announce a specific next study or timetable. Further work would need to test whether the short-term responses recur in larger or more varied groups, whether they influence eating behavior, and which features of food processing might account for the differences.
Until those questions are answered, the findings should be read as evidence of different short-term responses under the study conditions, not as a dietary recommendation or proof of long-term harm. Researchers will need longer-term evidence to connect the measured metabolic and brain responses with health outcomes associated with ultraprocessed food consumption.
Key Questions
What did the Virginia Tech study find?
Participants had different short-term metabolic responses after highly processed and minimally processed meals matched closely for calories and several nutrients. The study also found that differences in carbohydrate use were linked with differences in brain responses to food pictures.
Were the meals nutritionally identical?
They were not identical foods, but researchers matched them to within 1 percent for calories, carbohydrates, fat, protein, water and salt, and matched their weight. Their ingredients and processing levels differed.
Does the study prove ultraprocessed food causes disease?
No. It measured short-term responses in healthy adults and did not test long-term disease outcomes. The health conditions discussed in the report come from population-level associations, which do not establish cause and effect.
Did participants prefer the highly processed foods?
Participants did not say they were willing to pay more for either highly processed or minimally processed foods. The brain scans showed differences in responses to food images, but the study did not establish that those differences changed food choices.
Source: hn
Columbus Day / Indigenous Peoples' Day Picks
long weekend sales
As an affiliate, we earn on qualifying purchases.
