By Dr. Priyom Bose, Ph.D. Reviewed by Lauren Hardaker Apr 17 2026 A diet high in ultra-processed foods may do more than affect weight. It could be quietly reshaping muscle health, with MRI evidence revealing increased fat infiltration in those at risk of knee osteoarthritis.  Study: Ultra-processed Foods and Muscle Fat Infiltration at Thigh MRI: Data from the Osteoarthritis Initiative . Image credit: Thenongphoto/Shutterstock.com A recent  Radiology study examined how ultra-processed food (UPF)