Eating a lot of ultra-processed foods, like sodas, processed meats, snacks, and frozen meals, is linked to various health problems, including metabolic syndrome, type 2 diabetes, and some cancers. A recent study now suggests it might also affect muscle quality. The research presented at the Radiological Society of North America’s meeting discovered that people who consumed these foods regularly had more fat within their thigh muscles.
While healthy muscles do contain a bit of fat, having too much can impair movement and overall health. Sarah Alsing, a registered sports dietitian, points out that increased intramuscular fat can lead to a loss of strength and mobility and raises the risk for chronic diseases such as type 2 diabetes, obesity, and osteoarthritis.
The study, led by Zehra Akkaya, arose from earlier research linking a Western diet to poor knee health. Recognizing the role of ultra-processed foods in this diet, Akkaya’s team, who focus on knee osteoarthritis, decided to explore how these foods might affect muscle quality. Categorized as foods with added ingredients to prolong shelf life and taste, these ultra-processed items were the focus of their investigation.
The research examined data from 666 participants in the Osteoarthritis Initiative, a long-term study on knee osteoarthritis. At the study’s start, these participants did not show signs of knee pain or arthritis but were at risk of developing it. They filled out food frequency questionnaires and underwent MRIs to check the quality of their thigh muscles. The study specifically measured intramuscular fat, or fat within muscle fibers, finding that more ultra-processed food intake correlated with poorer muscle quality.
This correlation was independent of participants’ body mass index, calorie intake, age, gender, race, physical activity, or other sociodemographic factors. However, like any observational study, it shows a link but not a direct cause-and-effect relationship. William F. Harvey, interim chief of rheumatology at Tufts Medical Center, noted that unmeasured factors, like a diabetes diagnosis or high-fat diets, could also contribute to the increased intramuscular fat.
The study had limitations, such as relying on the Goutallier grading system, which isn’t as precise as quantitative methods for measuring muscle fat, and the accuracy of self-reported food intake. Going forward, experts suggest that studies should look into whether reducing ultra-processed food intake can lower intramuscular fat and how such fat affects health, particularly osteoarthritis.
Harvey mentions that while reducing these foods can prevent intramuscular fat development, exercise and strength training also play crucial roles in generating lean muscle and reducing fat. Following a generally healthy diet, rich in foods with minimal added sugars and rich in protein, fiber, and natural fats, like fruits, vegetables, whole grains, lean proteins, and healthy fats from sources like olives and avocados, is also advised to support muscle and overall health.
