Ultra‑processed food harms muscle
A new Radiology analysis found diets high in ultra‑processed foods were associated with more fat inside muscles on MRI — a marker of poorer muscle quality rather than just body weight. (nationaltoday.com) Reporters noted 41% of the study participants' diets were ultra‑processed and flagged common culprits—salty snacks, sugary drinks and fast food—as linked to the effect. (ktvh.com) (usatoday.com)
Magnetic resonance imaging works like a detailed internal camera, and in a new Radiology study it showed fattier thigh muscles in people who ate more ultra-processed food. (rsna.org) The researchers analyzed 615 adults in the Osteoarthritis Initiative, a National Institutes of Health-backed study, and published the results on April 14, 2026. The participants had no imaging evidence of osteoarthritis at baseline but were considered at risk for knee disease. (rsna.org) On average, participants were 60 years old, had a body mass index of 27, and got about 41% of their food over the prior year from ultra-processed products. The study found that higher ultra-processed food intake tracked with more fat inside thigh muscles even after accounting for calories, fat intake, physical activity and sociodemographic factors. (rsna.org) Fat inside and between muscle acts less like useful fuel and more like marbling in meat when it builds up beyond normal levels. NBC News reported the study focused on thigh muscle fat because higher levels are a risk factor for knee osteoarthritis. (nbcnews.com) The paper was a cross-sectional analysis, which means it measured diet and muscle scans at one point in time rather than testing cause and effect in a trial. The Radiology abstract says the data came from baseline Osteoarthritis Initiative records collected from February 2004 to October 2015. (pubs.rsna.org) The foods in question were industrial formulations such as breakfast cereals, packaged snacks, soft drinks, candies, frozen pizzas and ready-to-eat meals, according to the Radiological Society of North America. Other coverage of the study also highlighted salty snacks, sugary drinks and fast food as common examples. (rsna.org) (usatoday.com) Senior author Thomas Link of the University of California, San Francisco told NBC News that diet’s effect on muscles is less widely recognized than its links to heart disease and diabetes. Outside expert Christopher Fry of the University of Kentucky, who was not involved in the study, told NBC News that fat buildup can change how thigh muscles generate force and how knees absorb that force. (nbcnews.com) The study does not show that ultra-processed food alone caused the muscle changes, and it looked at a group already at risk for knee osteoarthritis rather than the whole population. It does show that body weight by itself did not explain the scan findings. (pubs.rsna.org) (rsna.org) The result adds muscle quality to a list of health problems already linked to ultra-processed diets. In this study, the warning sign was not just the number on a scale, but fat showing up inside the muscle on an imaging scan. (rsna.org)
