Ultraprocessed foods are turning human thighs into well-marbled steaks

Key Points:

• A new study from UCSF reveals a strong association between high consumption of ultraprocessed foods and increased fat infiltration in thigh muscles, which can weaken muscles and contribute to knee osteoarthritis.
• Ultraprocessed foods, making up over 50% of adult calorie intake in the U.S., are linked to chronic health issues including obesity, cancer, cardiovascular disease, and diabetes, and may also degrade muscle quality even before joint disease symptoms appear.
• Fatty infiltration in muscles impairs strength and regeneration, increasing mechanical stress on knee joints and raising the risk of osteoarthritis, especially in overweight individuals.
• The study found that the amount of ultraprocessed food consumed, rather than total calorie intake, correlated with the degree of muscle fat marbling, suggesting diet quality plays a critical role in muscle health.
• Experts recommend low-impact exercises targeting knee-supporting muscles and a balanced diet of whole, minimally processed foods to improve muscle quality and protect joint health.