Health / Nutrition

Ultra-Processed Diets Linked to Brain Response Predicting Fat Gain

In 46 children, the more ultra-processed food they ate, the harder a habit-forming brain region fired at food pictures — and the more body fat they gained in a year. The study can't prove cause.

Anika WellsAI editorial voice · 1 min read

A child at a healthy-snack event. In the USC study, ultra-processed products supplied about two-thirds of the children's daily calories. (U.S. Marine Corps, public domain)

Summary

A USC study found children who ate more ultra-processed food showed a stronger brain response to food images, which predicted fat gain.

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Children who ate more ultra-processed food showed a stronger brain response to food pictures, and that response predicted fat gain over a year. [Ultra-processed foods tied to brain reward response and fat gain in children, USC study finds — Global Agriculture]

USC's BrainChild study followed 46 children ages 7 to 10, all at a healthy weight when they enrolled, and published its findings October 23 in JAMA Network Open. Ultra-processed products supplied an average of 67.7% of the children's daily calories. [Ultra-processed foods tied to brain reward response and fat gain in children, USC study finds — Global Agriculture]

Each child had a brain scan while viewing pictures of appetizing foods. The response that tracked with diet sat in the dorsal striatum, a region involved in forming habits and linking cues with rewards. A neighboring region tied to pleasure and motivation, the ventral striatum, showed no significant link. Diets were classified with the NOVA system, which groups foods by how much they're processed rather than by nutrient content. [Ultra-processed foods tied to brain reward response and fat gain in children, USC study finds — Global Agriculture]

A stronger dorsal striatum response at the start predicted larger increases in BMI and body fat percentage over the next 12 months, and higher ultra-processed intake also tracked with a larger increase in waist size. When the researchers accounted for the brain response, the link between diet and BMI gain weakened by 31%, and the link with fat gain weakened by 44% — a pattern consistent with food-cue sensitivity being one route from these diets to weight gain. [Ultra-processed foods tied to brain reward response and fat gain in children, USC study finds — Global Agriculture]

The limits are plain. The study is observational, so it shows association rather than cause and effect. Forty-six children is a small sample, and one year of follow-up can't say whether the pattern persists into adolescence. The work, led by senior author Kathleen A. Page of USC's Keck School of Medicine with first author Jasmin M. Alves, was funded by an American Diabetes Association award and by the National Institute of Diabetes and Digestive and Kidney Diseases. [Ultra-processed foods tied to brain reward response and fat gain in children, USC study finds — Global Agriculture]

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