how do people develop fatty liver except alcohol abuse?

What are the causes of fatty liver besides alcohol?

•from Wikipedia: though commonly associated with alcohol, can also be due to many causes
Metabolic
Abetalipoproteinemia, glycogen storage diseases, Weber-Christian disease, acute fatty liver of pregnancy,lipodystrophy
Nutritional
Malnutrition, total parenteral nutrition, severe weight loss, refeeding syndrome, jejunoileal bypass, gastric bypass, jejunal diverticulosis with bacterial overgrowth
Drugs and toxins
Amiodarone, methotrexate, diltiazem, expired tetracycline, highly active antiretroviral therapy, glucocorticoids,tamoxifen, environmental hepatotoxins (e.g., phosphorus, mushroom poisoning)
Other
Inflammatory bowel disease, HIV, hepatitis C (especially genotype 3), and alpha 1-antitrypsin deficiency

•from google
Nonalcoholic fatty liver disease is now the most common cause of chronic liver disease in the U.S. Some people with excess fat in the liver simply have what's called a fatty liver. Although this is not normal, it is not serious if it doesn't lead to inflammation or damage.
Others have what's called nonalcoholic steatohepatisis (NASH). Although it is similar to alcoholic liver disease, people with this type of fatty liver disease drink little or no alcohol. NASH can lead to permanent liver damage. The liver may enlarge and, over time, liver cells may be replaced by scar tissue. This is called cirrhosis. The liver can't work right and you may develop liver failure, liver cancer, and liver-related death. NASH is one of the leading causes of cirrhosis.
Both types of NAFLD are becoming more common. Up to 20% of adults may have either fatty liver or NASH. And more than 6 million children have one of these conditions, which are most common in Asian and Hispanic children. Recent evidence indicates that NAFLD increases the risk of heart disease in children who are overweight or obese.
•Risk factors for fatty liver
Risk factors for Fatty liver
Your chances of developing fatty liver are high if you
 are obese
 are an alcoholic
 Suffer from high blood pressures which often fluctuate or are on long-term medications for the same.
 Blood cholesterol levels are high.

•Smoking may also contributes to fatty liver
Basic and clinical research have demonstrated that smoking alters enzymatic and inflammatory pathways in liver physiology, and is considered to be risk factor for liver neoplasm, and affects the prognosis of chronic liver disease.

•Even second-hand smoking may lead to liver disease
The researchers found fat accumulated in liver cells of mice exposed to second-hand cigarette smoke for a year in the lab. Such fat buildup is a sign of NAFLD, leading eventually to liver dysfunction.
In their study, the researchers focused on two key regulators of lipid (fat) metabolism that are found in many human cells as well: SREBP (sterol regulatory element-binding protein) that stimulates synthesis of fatty acids in the liver, and AMPK (adenosine monophosphate kinase) that turns SREBP on and off.
They found that second-hand smoke exposure inhibits AMPK activity, which, in turn, causes an increase in activity of SREBP. When SREBP is more active, more fatty acids get synthesized. The result is NAFLD induced by second-hand smoke.