Eating ultra-processed foods like breakfast cereals and ready meals is linked to more fat being stored in the thighs regardless of how many calories are consumed, new research suggests.
The study also found that diets high in ultra-processed foods impacted muscle quality regardless of exercise levels. Experts say higher amounts of fat in the thigh muscle could increase the risk for knee osteoarthritis.
"In an adult population at risk for but without knee or hip osteoarthritis, consuming ultra-processed foods is linked to increased fat within the thigh muscles," said Dr Zehra Akkaya.
Study author Zehra Akkaya, researcher and former Fulbright Scholar in the Department of Radiology and Biomedical Imaging at the University of California, San Francisco, US, explained: "The novelty of this study is that it investigates the impact of diet quality, specifically the role of ultra-processed foods in relation to intramuscular fat in the thigh muscles assessed by MRI."
"This is the first imaging study looking into the relationship between MRI-based skeletal muscle quality and quality of diet," she added.
Ultra-processed foods, which include items like frozen pizzas, fizzy drinks, and margarine, usually have longer shelf lives and are highly appealing due to their convenience and combination of sugar, fat, salt, and carbohydrates. These ingredients affect the brain's reward system, making it hard to stop eating.
In a new study presented at the annual meeting of the Radiological Society of North America, researchers set out to assess how ultra-processed food intake relates to fat in thigh muscles. They analysed data from 666 people who participated in the Osteoarthritis Initiative in the US—a nationwide research study aimed at better understanding how to prevent and treat knee osteoarthritis.
The findings revealed that increased consumption of ultra-processed foods was associated with more fat within thigh muscles irrespective of calorie intake. Dr Akkaya noted: "These findings held true regardless of dietary energy content, BMI (Body Mass Index), sociodemographic factors or physical activity levels."
"Targeting modifiable lifestyle factors—mainly prevention via a healthy diet and adequate exercise—has been central to initial management for knee osteoarthritis," she stated.
"Osteoarthritis is an increasingly prevalent and costly global health issue. It is a major contributor to non-cancer related healthcare costs globally," Dr Akkaya emphasized. "Since this condition is highly linked to obesity and unhealthy lifestyle choices, there are potential avenues for lifestyle modification and disease management."