Fatty liver disease can be caused by which of the following?

Fatty liver disease, also known as hepatic steatosis, can be caused by multiple factors that lead to an accumulation of fat in liver cells. Excessive alcohol intake is a well-documented cause, leading to alcoholic fatty liver disease, where alcohol metabolism disrupts lipid metabolism and promotes fat accumulation in hepatocytes.

Hyperlipidemia contributes to fatty liver disease by increasing the levels of circulating lipids, which can be taken up by the liver and cause steatosis. When the liver is overwhelmed by these excess lipids, it fails to export them effectively, resulting in the accumulation of fat within liver tissue.

Obesity is another significant risk factor for fatty liver disease. It is often associated with metabolic syndrome in which insulin resistance occurs, leading to increased delivery of free fatty acids to the liver and impaired fatty acid oxidation, thereby promoting fat accumulation.

When considering all these factors—excessive alcohol intake, hyperlipidemia, and obesity—it's clear that each one can independently contribute to the development of fatty liver disease. Thus, the most comprehensive answer that encapsulates the various etiologies of this condition is that all of the options provided are valid causes of fatty liver disease.