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
A Virginia Tech study of 57 healthy adults found that nutritionally matched meals with different levels of processing produced different metabolic responses. Brain scans also showed differences in reward-related activity linked to how participants burned carbohydrates, though they did not report valuing one meal type more than the other.
Virginia Tech researchers found that meals with different levels of processing prompted distinct metabolic responses even when the meals were matched for calories, carbohydrates, fat, protein, water, salt and weight. In a study of 57 healthy adults, ultraprocessed meals were associated with higher insulin responses and differences in energy use, while brain scans linked participants’ carbohydrate burning after meals with activity in reward-related regions.
The study, published this month in Nature Metabolism, compared each participant’s response to a minimally processed meal and an ultraprocessed meal during separate sessions. At least three days separated the sessions. The researchers recruited adults aged 18 to 45; 32 completed both the metabolic and brain-imaging sessions.
For the metabolic tests, participants fasted overnight and ate a 300-calorie meal within 10 minutes. The ultraprocessed selection included small portions of a peanut butter and jelly sandwich, deli turkey, veggie chips, a cookie, cereal, instant mashed potatoes and water. The minimally processed meal consisted of banana, dried cranberries, cheese and egg. The meals were matched within 1 percent for the listed nutritional measures, according to first author Zach Hutelin.
Researchers measured metabolism in an airtight chamber and took blood samples after eating, including at six points over the following three hours. They reported higher insulin responses after the ultraprocessed meal, along with differences in energy expenditure and carbohydrate oxidation. Participants also viewed food images during functional MRI scans on another day. Brain responses in the ventral striatum and nucleus accumbens—regions involved in motivation and reward—varied in relation to differences in carbohydrate burning. Participants did not say they would pay more for either type of food.
Processing May Shape Food Responses
The findings suggest that processing level may be associated with responses that are not fully captured by calories and the measured amounts of major nutrients. This offers researchers a possible avenue for investigating how ultraprocessed foods relate to eating behavior and health, without establishing that processing itself causes disease or overeating.
The question has public-health relevance because, according to the report, ultraprocessed foods provide more than half of the average American’s daily calories, and diets in many parts of the world are shifting toward them. Such products are often made to be convenient, affordable and appealing. The study’s results may help explain mechanisms behind previously reported associations, but they do not show that a particular meal or processing category will produce the same effects in everyone.
As an affiliate, we earn on qualifying purchases.
How Researchers Isolated Processing
Ultraprocessed foods are commonly high in fat and sugar and low in fiber and protein, according to Virginia Tech associate professor Alex DiFeliceantonio. Those differences can complicate efforts to determine whether observed health patterns relate to processing, nutritional composition or both. The research team asked whether responses would still differ when key nutritional measures were held nearly constant.
Participants ate the two meals in controlled sessions, allowing the researchers to compare responses within the same person. In a separate imaging session, they viewed pictures of matched foods and rated how much they would pay for them. The report describes this as an investigation of immediate metabolic and brain responses—not a long-term diet trial. Earlier population research has associated high consumption of ultraprocessed foods with obesity, cardiovascular events and Type 2 diabetes, but those associations alone do not establish cause.
“If we artificially hold all of those things constant, is there something about the processing that leads to a different outcome?”
— Alex DiFeliceantonio, associate professor at the Fralin Biomedical Research Institute at VTC
As an affiliate, we earn on qualifying purchases.
Limits of the Meal Comparison
The findings describe responses to one controlled 300-calorie meal in healthy adults, not the effects of eating an ultraprocessed diet over months or years. The supplied report does not provide numerical effect sizes, participant-level variation or enough detail to determine how large or persistent the observed differences were.
It is also unclear which features of processing could account for the results. Matching calories and several nutrients does not mean the meals were identical in every respect, and the study does not establish that processing caused the brain-response differences or that those differences lead to greater consumption. The participants’ stated willingness to pay did not differ between food types. The supplied source text ends while introducing a debate about how to interpret associations between ultraprocessed foods and poor health, so it does not provide the researchers’ full discussion of that point.
As an affiliate, we earn on qualifying purchases.
Further Work on Processing Effects
The report points to further research into how processing may relate to metabolic and brain responses, and how those responses connect to food choice and longer-term health. The supplied material does not announce a follow-up study, a timeline or a planned change to dietary guidance.
Readers should treat the results as early mechanistic evidence rather than proof that processing alone determines health outcomes. Larger and longer studies could help test whether the short-term differences persist, identify which aspects of processing matter, and establish whether measured brain responses predict eating behavior outside a laboratory.
As an affiliate, we earn on qualifying purchases.
Key Questions
What did the Virginia Tech study find?
Researchers reported that ultraprocessed and minimally processed meals matched on several nutritional measures produced different metabolic responses. They also found brain-imaging differences related to participants’ carbohydrate burning after the meals.
Were the meals matched for calories and nutrients?
Yes. Each meal contained 300 calories, and the study report says the meals were matched within 1 percent for carbohydrates, fat, protein, water and salt, as well as for weight.
Did participants prefer the ultraprocessed foods?
Participants did not report being willing to pay more for either the ultraprocessed or minimally processed foods. The brain-scan findings therefore should not be described as evidence that participants consciously preferred one category.
Does the study prove ultraprocessed food causes diabetes?
No. The study measured short-term responses after controlled meals. It does not establish that ultraprocessed foods cause diabetes or other long-term conditions.
How many people took part?
The full study included 57 adults aged 18 to 45. Of those, 32 completed both the brain-imaging and metabolic sessions, according to the report.
Source: hn
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
