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By Megan Ng

Non-alcoholic fatty liver disease (NAFLD) is a condition caused by a build-up of fat in liver cells. In a healthy body, the liver removes toxins and produces bile, a protein that breaks down fat into fatty acids to be digested (Definition & Facts of NAFLD & NASH, n.d.). Fatty liver disease causes damage to the liver and prevents it from working.

NAFLD is high risk in certain individuals. For example,  you could be at greater risk if you are an individual that is or has at least one or more of the conditions below : (Non-alcoholic fatty liver disease (NAFLD), n.d.)

  • Obesity or overweight, and if you carry a lot of your weight in your midsection
  • Type 2 diabetes
  • PCOS
  • High blood pressure
  • Underactive thyroid
  • High cholesterol
  • Metabolic syndrome (a combination of diabetes, high blood pressure, and obesity)
  • Smoke
  • Over the age of 50

Stages and Types of Fatty Liver Disease

(Non-alcoholic fatty liver disease (NAFLD), n.d.); (Sweet et al., 2017)

  1. Simple fatty liver is also known as non-alcoholic fatty liver (NAFL and steatosis). NAFL is when there is fat buildup in the liver cells with little or no inflammation or liver damage. NAFL typically does not progress to cause liver damage or complications. However, NAFL can cause pain from enlargement of the liver. Most people will develop this first stage without knowing.
  2. Non-alcoholic steatohepatitis (NASH) is a more severe form of NAFLD in which there is inflammation of the liver and liver damage. It is important to note that there is still a buildup of fat in the liver in addition to inflammation. The inflammation and liver damage can cause scarring of the liver. NASH may lead to cirrhosis.
  3. Fibrosis can be developed from NASH and the continued inflammation of the liver. Fibrosis is the buildup of scar tissue around the liver and surrounding blood vessels. The excess scar tissue can block blood flow to parts of your liver (Dulai et al., 2017).
  4. Cirrhosis is the most severe and irreversible stage. This occurs when the liver is under prolonged inflammation. The buildup of scar tissue causes permanent damage to the liver which can lead to liver failure and liver cancer. This is the stage where a liver transplant may be necessary.

Knowing the difference between the stages and types of fatty liver disease is important because most people with fatty liver do not realize it. Many individuals with simple fatty liver do not experience any sickness, symptoms, or inflammation that occurs in the more developed stages of fatty liver disease (Armand, 2020). This characteristic of simple fatty liver can be dangerous because it can quickly progress to more severe stages. The risk of progression is high in non-alcoholic fatty liver disease.


Prevention and being proactive are key to stopping the progression of fatty liver disease. There are currently no specific medications for NAFLD, but the most effective treatments so far are lifestyle changes. Implementing more healthy habits like limiting alcohol, added sugars, and saturated fats; losing weight, and consuming more nutrient-dense foods are important in decreasing your risk and helping the management of NAFLD. Getting screened for NAFLD and having regular appointments with your health professional are other crucial steps to take for optimal liver health.


  1. Armand, W. (2020). Fatty liver disease: What it is and what to do about it. Harvard Health. Retrieved 28 September 2022, from
  2. Definition & Facts of NAFLD & NASH. National Institute of Diabetes and Digestive and Kidney Diseases. Retrieved 28 September 2022, from
  3. Dulai, P., Singh, S., Patel, J., Soni, M., Prokop, L., & Younossi, Z. et al. (2017). Increased risk of mortality by fibrosis stage in nonalcoholic fatty liver disease: Systematic review and meta-analysis. Hepatology, 65(5), 1557-1565.
  4. Non-alcoholic fatty liver disease (NAFLD). NHS. Retrieved 28 September 2022, from
  5. Sweet, P., Khoo, T., & Nguyen, S. (2017). Nonalcoholic Fatty Liver Disease. Primary Care: Clinics In Office Practice, 44(4), 599-607.

Megan Ng is a graduate student of Food Science and Human Nutrition at the University of Illinois at Urbana Champaign

Free image by Mohamed Hassan from Pixbay