Although the cause of nonalcoholic fatty liver disease is unclear, the condition is associated with many risk factors. The three most important ones are closely related to metabolic syndrome and insulin resistance:

 *Overweight and obesity. Your risk increases with every pound of excess weight. More than 70 percent of people with nonalcoholic steatohepatitis (NASH) are obese. Overweight is defined as having a body mass index between 25 and 29.9; obesity is defined as having a body mass index of 30 or higher.

 *Diabetes. When your body becomes resistant to the effects of insulin or your pancreas doesn't produce enough insulin to maintain a normal blood sugar (glucose) level, this can damage many organs in your body, including your liver . As many as three in four people with NASH also have diabetes.

 *Hyperlipidemia. High cholesterol levels and elevated triglycerides are common in people who develop NASH. It's estimated that up to 80 percent of people with NASH have hyperlipidemia.

Other risk factors include:

 *Abdominal surgery.
 *Medications.
 *Other conditions.