People are eating less and less natural foods. They are being replaced by highly processed foods that contain artificial flavors, colors, and chemical additives. These include fast food, ready-made snacks, cold meats, sugary soft drinks, baked goods, frozen pizza, and mass-produced baked goods. Ultra-processed foods are designed to appeal to consumers: they are convenient, have a long shelf life, and have a strong flavor. The combination of sugar, fat, salt, and carbohydrates creates a rewarding effect, making us want to eat more.
The researchers set out to assess the association between ultra-processed food consumption and intramuscular fat in the hips. To do this, they used MRI and data from 666 people who were part of the Osteoarthritis Initiative. The participants did not yet have osteoarthritis, but were at risk for developing it.
There is a link between loss of muscle mass and strength in the hip and the progression of knee osteoarthritis. On MRI images, this loss can be seen as fatty degeneration of the muscle, where bands of fat replace muscle fibers.
The average age of the study participants (455 men and 211 women) was 60. They were, on average, overweight with a BMI of 27. About 40% of their diet was ultra-processed foods. The study found that the more ultra-processed foods people consumed, the more intramuscular fat they had in their thigh muscles, regardless of calorie intake.
Initial treatment for knee osteoarthritis focuses on lifestyle changes: a balanced diet and physical activity to reduce weight.