A fatty liver means that fat makes up more than 5% to 10% of your liver’s total weight. Every liver contains some fat, but beyond that threshold, the extra buildup can interfere with how the organ functions and, in some cases, lead to serious damage over time. The condition is extremely common and often discovered by accident during imaging for something else entirely.
Why Fat Builds Up in the Liver
Your liver processes fats from the food you eat and from fat stored elsewhere in your body. When more fat arrives than the liver can handle, or when metabolic signals go haywire, triglycerides start accumulating inside liver cells. Over time, those cells become swollen with fat droplets that don’t belong there.
The most common form of fatty liver is now called metabolic dysfunction-associated steatotic liver disease, or MASLD. You may also see it referred to by its older name, NAFLD (nonalcoholic fatty liver disease). The medical community updated the terminology in 2023 partly because the old name defined the condition by what it wasn’t (not caused by alcohol) rather than what it was (driven by metabolic problems). Surveys also found that the words “nonalcoholic” and “fatty” felt stigmatizing to a majority of patients.
To receive an MASLD diagnosis, a person needs to have liver fat plus at least one of five cardiometabolic risk factors. These include excess body weight, elevated blood sugar or insulin resistance, high blood pressure, and abnormal cholesterol or triglyceride levels. A separate category, called MetALD, covers people who have both metabolic risk factors and moderate-to-heavy alcohol use.
Why Most People Don’t Feel Anything
Fatty liver is sometimes called a silent liver disease because it rarely produces symptoms in its early stages. Most people with fat in their liver never develop liver damage at all. The condition can sit quietly for years, even decades, without making itself known.
When symptoms do appear, they tend to be vague: persistent tiredness, a general sense of not feeling well, or a dull ache in the upper right side of your abdomen (where the liver sits, just below the ribs). These are easy to attribute to stress, poor sleep, or aging, which is one reason fatty liver so often goes undetected. If the disease progresses to a more advanced stage called MASH (metabolic dysfunction-associated steatohepatitis), symptoms may eventually surface, but it can take years.
How Fatty Liver Gets Diagnosed
Many people first learn they have a fatty liver after an abdominal ultrasound shows unusual brightness in the liver tissue. Ultrasound is painless and widely available, making it the most common first step. But it has limits: it can miss milder cases and can’t easily tell the difference between simple fat accumulation and more advanced inflammation or scarring.
A more precise option is a specialized scan called transient elastography (often known by the brand name FibroScan). This device measures two things at once: how much fat is in the liver (using a measurement called controlled attenuation parameter, or CAP) and how stiff the liver tissue is, which indicates scarring. Research shows CAP is highly accurate at detecting even mild fat accumulation, though the readings need to be interpreted differently for people with a BMI over 30, since higher body weight can shift the numbers upward.
The Spectrum From Mild to Serious
Not all fatty livers are created equal. The condition exists on a spectrum, and where you fall on it matters a great deal.
At one end is simple steatosis: fat in the liver with no significant inflammation or scarring. This is where the vast majority of people with fatty liver sit, and many stay here indefinitely without complications. At the next stage, MASH, the fat triggers chronic inflammation that starts damaging liver cells. If that inflammation continues unchecked, scar tissue forms (fibrosis). Advanced scarring can eventually harden into cirrhosis, where the liver loses its ability to function properly. Cirrhosis also raises the risk of liver cancer.
The progression from simple fat to cirrhosis is not inevitable. Most people never advance beyond the earliest stage. But there’s no reliable way to predict who will progress, which is why catching and addressing it early matters.
What Actually Reverses Fatty Liver
The most effective treatment for fatty liver is weight loss, and the research is specific about how much is needed. Losing 3% to 5% of your body weight is typically enough for fat to start clearing out of liver cells. But if inflammation or scarring has already begun, a greater loss of around 10% of body weight is needed to improve those changes. For someone weighing 200 pounds, that’s 6 to 10 pounds for fat reduction and 20 pounds for inflammation improvement.
No medication is currently approved as a standard treatment for MASLD in most cases, which makes lifestyle changes the primary tool. Exercise helps even when it doesn’t produce dramatic weight loss, because physical activity improves how your body handles insulin and processes fat.
What to Eat (and What to Avoid)
The Mediterranean diet has the strongest evidence behind it for people with fatty liver. It emphasizes fruits, vegetables, whole grains, lean proteins, and healthy fats, particularly olive oil. The combination is naturally high in fiber, vitamins, and plant compounds that reduce inflammation.
A practical way to structure meals is the plate method: fill half your plate with non-starchy vegetables or fruits, one quarter with whole grains or starchy vegetables, and the last quarter with protein like fish, poultry, or beans. Aim for three or more servings of fish per week, especially fatty cold-water varieties like salmon, sardines, mackerel, and trout, which are rich in omega-3 fatty acids that help reduce liver fat.
Cooking with plant-based oils (olive, avocado, or grapeseed) instead of butter makes a measurable difference. Black coffee, green tea, and walnuts contain plant compounds called polyphenols that have antioxidant and anti-inflammatory effects shown to help reduce liver fat. Some research also suggests that omega-3 supplements and vitamin E may improve liver fat and inflammation, though these are best discussed with your doctor before starting.
On the other side of the equation, added sugars are particularly harmful to a fatty liver. Sugary drinks, refined carbohydrates, and highly processed foods all promote the kind of insulin resistance and triglyceride buildup that drives the condition. Alcohol, even in moderate amounts, adds further stress to a liver already dealing with excess fat.
Why It Matters Beyond the Liver
Fatty liver is not just a liver problem. The same metabolic dysfunction that causes fat to accumulate in the liver also increases your risk of heart disease, type 2 diabetes, kidney disease, and stroke. In fact, cardiovascular disease is the leading cause of death in people with MASLD, not liver failure. That’s why the updated diagnostic criteria require at least one cardiometabolic risk factor: the condition is deeply intertwined with the broader health of your heart and blood vessels.
Addressing fatty liver through weight loss, diet, and exercise doesn’t just protect your liver. It improves blood sugar control, lowers blood pressure, and shifts cholesterol numbers in a healthier direction. Treating the liver, in other words, treats the whole picture.