Recent research has uncovered a significant association between higher levels of ultra-processed food in the diet and an increase in fat within the muscles, along with a greater risk of conditions like osteoarthritis. Dr. Zehra Akkaya, a researcher at the University of California, San Francisco, stated that in an adult population at risk for but without knee or hip osteoarthritis, consuming ultra-processed foods is linked to elevated fat within the thigh muscles. These findings remain consistent regardless of dietary energy content, BMI, sociodemographic factors, or physical activity levels.

Understanding Ultra-Processed Food

Ultra-processed food refers to industrially processed items that utilize artificial additives and refined ingredients to create packaged products sold in stores. These additives, such as preservatives, thickeners, colorings, flavorings, emulsifiers, and others, are designed to make the food convenient, shelf-stable, and highly palatable, thereby encouraging us to purchase and consume more. It's important to note that ultra-processed food isn't limited to obvious junk food like chips and crackers; it can also include seemingly healthy items like sliced bread and fruit-flavored yogurt.

Impact on Muscle Health

Excess fat in muscles is associated with various issues such as muscle weakness, poor muscle quality, and conditions like obesity, type 2 diabetes, and insulin resistance. This is partly because it disrupts the body's food processing mechanisms. In a study analyzing the diets of over 650 older individuals in the US and intramuscular fat using information from food questionnaires and MRI scans, it was found that a higher intake of ultra-processed food was correlated with more thigh muscle fat. On average, the participants were 60 years old, overweight, and consumed diets that were 40 percent ultra-processed food, which is lower than the US average.

Association with Osteoarthritis

Osteoarthritis is the most common form of arthritis, causing joint pain, stiffness, and swelling that can lead to changes in bones, cartilage, and other joint tissues. It is most prevalent in adults over 45 and has risk factors like repetitive joint stress or injury, being overweight, and being female. Research has shown that quantitative functional decline in thigh muscles is potentially linked to the onset and progression of knee arthritis. Understanding the relationship between diet quality and musculoskeletal health is crucial as it offers a new perspective on how to manage these health issues.Do you have a tip on a food story that Newsweek should be covering? Is there a nutrition concern that’s worrying you? Let us know via science@newsweek.com. We can ask experts for advice, and your story could be featured in Newsweek.