Study links ultra-processed food intake to higher fat infiltration in thigh muscles

Higher consumption of ultra-processed foods is associated with greater fat infiltration in thigh muscles, according to a cross-sectional secondary analysis of more than 600 adults at risk for knee osteoarthritis.

Researchers used thigh MRI scans to evaluate fat infiltration across 10 different muscles and compared the results with participants’ self-reported dietary intake of ultra-processed foods.

Key findings The analysis found that higher intake of ultra-processed foods was linked to higher levels of fat infiltration in thigh muscles. The association held independently of total caloric intake and overall dietary fat consumption.

Women showed higher overall levels of thigh muscle fat infiltration than men. However, the relationship between ultra-processed food intake and muscle fat infiltration appeared consistent across sexes.

The link between ultra-processed food consumption and thigh muscle fat infiltration was stronger among participants who showed more severe knee damage on imaging.

Limits and next steps The researchers noted several limitations. The study focused on an older group already at risk for knee osteoarthritis, which may limit how broadly the findings apply. Because the analysis was cross-sectional, it cannot determine whether ultra-processed foods cause the observed muscle changes. Dietary information was also self-reported, which can introduce measurement errors.

The authors said longitudinal studies are needed to examine causality and to test whether similar associations appear in other populations and muscle groups.