Metabolic dysfunction-associated steatohepatitis (MASH) is a form of fatty liver disease that promotes inflammation and damage over time. Closely connected to conditions like obesity and insulin resistance, MASH affects nearly one-third of people worldwide. A recent study found that a long-term intervention combining calorie restriction and high-intensity interval training (HIIT) in people with MASH improved liver function, doubling insulin sensitivity.

Researchers assigned people with MASH to either a treatment group (16 participants) that received lifestyle counseling and exercise training or a control group (eight participants) that continued with standard medical care. The treatment group engaged in supervised HIIT three times a week while reducing caloric intake. The researchers assessed the participants' liver fat, measured blood biochemistries, and evaluated insulin sensitivity before and after the intervention.

They found that the treatment group experienced notable reductions in body weight, fat mass, and liver injury. Their cardiorespiratory fitness improved considerably, and they exhibited a twofold increase in peripheral insulin sensitivity compared to the control group. Both groups saw reductions in total energy intake and liver fat.

These findings suggest that combining caloric restriction with regular high-intensity exercise can yield marked improvements in liver health and insulin sensitivity, likely by redistributing excess nutrients to skeletal muscle. Learn more about calorie restriction in this clip featuring Dr. David Sinclair, and HIIT in this clip featuring Dr. Martin Gibala.