Metabolic dysfunction-associated steatotic liver disease (MASLD, formerly known as non-alcoholic fatty liver disease, or NAFLD), involves the buildup of fat in the liver. Over time, this can progress to a more severe condition known as metabolic dysfunction-associated steatohepatitis (MASH, formerly known as non-alcoholic steatohepatitis, or NASH). Estimates suggest that around a third of Americans have fatty liver disease, but many remain undiagnosed.

Steatotic liver disease often has no symptoms during its early stages. But over time, liver fat buildup can lead to liver fibrosis (buildup of scar tissue), cirrhosis and liver cancer. People who progress to cirrhosis may experience serious complications including fluid retention (edema and ascites), bleeding blood vessels in the esophagus or stomach and cognitive problems (hepatic encephalopathy). Now that hepatitis B can be prevented with vaccines and hepatitis C can be easily cured, fatty liver disease has become a leading cause of liver cancer and liver transplants. What’s more, many people with MASLD or MASH have obesity, type 2 diabetes and other metabolic problems, and cardiovascular disease is a leading cause of illness and death.

There are currently no approved medical treatments for MASLD and MASH, but this is an active area of clinical research, and numerous candidates are in the pipeline. In the meantime, management of fatty liver disease relies on lifestyle changes, such as diet, exercise, weight loss and limiting alcohol consumption. Management of high blood sugar, abnormal cholesterol and high blood pressure may slow disease progression. In some cases, weight-loss medications, such as semaglutide (Wegovy) or tirzepatide (Zepbound), and bariatric surgery may be an option.