In this cohort study of children of healthy weight, higher habitual UPF intake was associated with greater dorsal striatal responses to food cues and prospective increases in adiposity, suggesting that reward-related brain responses may be involved in associations between UPF consumption and adiposity gain during childhood.
Key Findings
Results
Higher habitual ultraprocessed food (UPF) intake was associated with greater BOLD responses to food cues in the dorsal striatum.
Association: β = 0.34; 95% CI, 0.07-0.61, per SD change in exposure and outcome.
Sample: 46 children of healthy weight (mean [SD] age 8.7 [1.1] years; 26 [57%] female).
Habitual UPF intake was the percentage of total energy from UPFs, based on multiple 24-hour dietary recalls using the NOVA classification.
Models were linear regressions adjusted for age, sex, baseline BMI, and total caloric intake.
Results
Habitual UPF intake was not significantly associated with BOLD responses to food cues in the ventral striatum.
Association: β = 0.16; 95% CI, -0.14 to 0.46.
The confidence interval includes zero, in contrast to the dorsal striatum finding.
Results
Greater dorsal striatal food cue responsivity at baseline was associated with 1-year increases in BMI and body fat percentage.
BMI: β = 0.32; 95% CI, 0.02-0.62.
Body fat percentage: β = 0.44; 95% CI, 0.15-0.72.
Adiposity was measured at baseline and again about 1 year later.
Results
Baseline UPF intake was associated with a 1-year increase in waist circumference.
Association: β = 0.38; 95% CI, 0.11-0.66.
Adjusted for age, sex, baseline BMI, and total caloric intake.
Results
UPF intake had positive point estimates for 1-year increases in BMI and body fat percentage, but the confidence intervals' lower bounds were at 0.00.
BMI: β = 0.28; 95% CI, 0.00-0.57.
Body fat percentage: β = 0.29; 95% CI, 0.00-0.57.
The abstract describes these as positive point estimates, not clearly significant associations.
Results
Including dorsal striatal responsivity in the models attenuated the associations between UPF intake and 1-year adiposity change.
Attenuation was 31% for change in BMI.
Attenuation was 44% for change in body fat percentage.
The authors interpret this as suggesting reward-related brain responses may be involved in the UPF-adiposity associations.
Methods
The study was a prospective cohort of healthy-weight children combining MRI, dietary recall, and adiposity measures.
Part of the longitudinal BrainChild study; baseline assessments ran April 11, 2015 to June 28, 2024, with 1-year follow-up of adiposity (April 18, 2016 to June 19, 2025).
Baseline BMI range was 13.8-19.9 and body fat percentage range was 12.7%-32.2%.
Brain outcomes were BOLD responses to food cues in the dorsal and ventral striatum during functional MRI.
Adiposity outcomes were 1-year changes in BMI, body fat percentage, and waist circumference.
What This Means
This study followed 46 healthy-weight children, about 9 years old on average, to see whether eating more ultraprocessed foods (such as packaged snacks and ready-to-eat products) was linked to how their brains respond to pictures of food, and whether this was linked to gaining body fat over the next year. Researchers measured diet using several 24-hour food recalls, scanned the children's brains with MRI while they viewed food cues, and measured body size and fat at the start and one year later.
Children who got a larger share of their calories from ultraprocessed foods showed stronger responses to food cues in the dorsal striatum, a brain region involved in reward and habit-related behavior. No clear link was seen in the ventral striatum. Stronger dorsal striatal responses were in turn linked to larger one-year increases in BMI and body fat percentage, and higher ultraprocessed food intake was linked to a larger increase in waist circumference. Links between ultraprocessed food intake and BMI or body fat gain were positive but borderline. Accounting for dorsal striatal responses reduced these links by about 31% for BMI and 44% for body fat.
This research suggests that reward-related brain responses may help explain how ultraprocessed food consumption relates to weight gain in childhood. Because this was an observational study with a small sample and a one-year follow-up, it cannot show that ultraprocessed foods cause these brain or body changes, and larger studies would be needed to confirm the findings.
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Alves J, Morgan E, Angelo B, Le K, Smith J, Chow T, et al.. (2026). Ultraprocessed Food Intake, Striatal Response to Food Cues, and Adiposity Gain in Children.. JAMA network open. https://doi.org/10.1001/jamanetworkopen.2026.40252