A diet high in ultra-processed foods, like fizzy drinks, processed meats, snacks, and frozen meals, has been linked to health problems such as metabolic syndrome, type 2 diabetes, and some cancers. A new study suggests that consistently eating these foods might also harm muscle quality, particularly increasing fat within thigh muscles.
This research, presented at the Radiological Society of North America meeting on December 4, highlights that excess fat in muscles can impair movement and health. Sarah Alsing, a sports dietitian, notes that increased intramuscular fat is linked to lower strength and mobility and higher risks of chronic diseases like type 2 diabetes, obesity, and osteoarthritis.
Previous studies have indicated that a more Western-style diet is associated with poor knee health. This finding led Zehra Akkaya and her team to investigate the Western diet, which is rich in ultra-processed foods, in more detail.
Ultra-processed foods typically contain high levels of added sugars, salts, and preservatives to make them last longer and taste better. The study utilized data from 666 individuals involved in the Osteoarthritis Initiative, who initially showed no symptoms of knee osteoarthritis but were at risk. Their average body mass index was 27, classified as overweight.
Participants completed food frequency surveys and underwent MRIs to evaluate thigh muscle quality and intramuscular fat content, which could be a factor in developing knee osteoarthritis. The study revealed a clear connection between consuming more ultra-processed foods and having poorer thigh muscle quality, showing more fatty tissue relative to healthy muscle.
This association was observed independently of factors like body mass index, calorie consumption, age, gender, race, and physical activity levels. However, being an observational study, it can only point to correlations rather than direct causation. Potential unmeasured factors, such as diabetes diagnoses or the intake of saturated fats, might also contribute to the fat increase.
The study had limitations, including its reliance on the Goutallier grading system, which may not be as accurate as other methods for measuring muscle fat. Additionally, self-reported food intake can often be unreliable.
Experts suggest further research to determine if reducing ultra-processed food consumption could lower existing intramuscular fat and better understand how this fat impacts health, especially osteoarthritis. While diet plays a role, exercise and strength training are also effective in promoting lean muscle and reducing intramuscular fat.
Adopting a healthy diet, focused on foods with minimal added sugars and rich in protein, fiber, and natural healthy fats, can support overall health and help manage intramuscular fat. It’s beneficial to consume a variety of fruits, vegetables, whole grains, nuts, seeds, lean proteins, and healthy fats like those from olives and avocados.
