Understanding Fatty Liver (Hepatic Steatosis)
What Is Fatty Liver?
Fatty liver means your liver has accumulated too much fat—specifically, when fat makes up at least 5% of your liver's weight. 1, 2 This condition is also called hepatic steatosis or metabolic dysfunction-associated steatotic liver disease (MASLD). 3
Your liver normally contains some fat, but when excess fat builds up, it can affect how your liver works. 4
How Common Is This?
- If you have obesity, there's a 70% chance you have fatty liver. 1
- If you have type 2 diabetes, the chance rises to 70-90%. 5, 1
- Even in the general population without these conditions, 20-30% of people have fatty liver. 3
Why Does Fat Build Up in the Liver?
The main culprit is insulin resistance—when your body doesn't respond properly to insulin. 1 This causes several problems:
- Your fat tissue releases 50-70% more fatty acids into your bloodstream, which flow directly to your liver. 1
- Your liver starts making 5 times more fat than normal through a process called de novo lipogenesis. 1
- Your liver tries to package and export this fat, but it can't keep up with the excess. 1
Additional contributors include:
- Eating too much fructose (sugar) stimulates fat production in your liver and may worsen inflammation. 1
- Certain genetic factors, especially if you have Hispanic ancestry or a family history of diabetes. 1
- Drinking significant alcohol (more than 21 drinks per week for men or 14 for women). 5
What Are the Two Types?
Most people (70-75%) have simple fatty liver, which is relatively stable and doesn't cause immediate harm. 2, 3 However, 25-30% develop steatohepatitis (inflamed fatty liver), where fat accumulation triggers inflammation and liver cell injury. 2, 3 This second type can progress to scarring (fibrosis), cirrhosis, liver failure, or liver cancer. 3
Will I Have Symptoms?
Most people with fatty liver have no symptoms at all—60-80% remain completely asymptomatic. 2 This is why many cases go undetected until discovered on imaging or blood tests done for other reasons. 2
What Should You Do?
The cornerstone of treatment is lifestyle modification focused on weight loss and metabolic health. 3 Specifically:
- Lose weight through diet and exercise—even 5-10% weight loss can significantly reduce liver fat. 3
- Control your blood sugar if you have diabetes—your doctor may recommend medications like GLP-1 receptor agonists (incretin-based therapies). 3
- Manage cholesterol and blood pressure. 3
- Avoid or minimize alcohol consumption. 5
- Reduce dietary fructose and added sugars. 1
For severe obesity, bariatric surgery may be an option. 3
Important Points to Remember
- Fatty liver is strongly linked to obesity, diabetes, high cholesterol, and high blood pressure—these conditions often occur together. 1, 2
- The presence of liver scarring (fibrosis) is the most important factor determining your long-term outcome. 5 Your doctor may order additional tests to check for this.
- Cardiovascular disease (heart attack and stroke) is actually the most common cause of death in people with fatty liver, not liver failure. 5
- Many doctors underestimate how common fatty liver is in high-risk patients, so advocate for screening if you have obesity or diabetes. 5, 1
Follow-Up
Work closely with your primary care doctor, and they may refer you to specialists in liver disease (hepatology), weight management (obesity medicine), or diabetes care (endocrinology) depending on your specific situation. 5 Regular monitoring with blood tests and imaging helps track whether your liver condition is stable or progressing. 3