UPDATED BY FRANZISKA SPRITZLER, RD, CDCES
Fifty years ago, the condition we now know as Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) didn’t even have a name. In 1986, it was recognized as non-alcoholic fatty liver disease (NAFLD), a term that remained in use until 2023, when it was updated to MASLD to better reflect its underlying metabolic drivers.
Today, MASLD affects an estimated 38% of adults and 7–14% of children and teens, and if current trends continue, more than half of all adults are expected to have the condition by 2040.
This rise in fatty liver disease closely mirrors the obesity epidemic. You may already know that a well-formulated ketogenic diet can support healthy weight loss. But what are its effects on fatty liver?
Let’s take a closer look at what the research shows. But first, we’ll explore what MASLD is and why it matters.
What Is MASLD?
MASLD is the buildup of excess fat in the liver – known as hepatic steatosis – that occurs in people who consume little or no alcohol. It’s closely tied to insulin resistance and other signs of metabolic dysfunction, such as elevated blood glucose levels and central obesity (carrying excess fat around the abdomen).
The condition is often discovered during imaging, such as an ultrasound, typically following elevated liver enzymes (ALT and AST) on routine bloodwork. In some cases, a liver biopsy may be needed to evaluate inflammation or fibrosis.
While MASLD is often silent and doesn’t always lead to serious complications, it can progress to a more severe form called MASH (Metabolic Dysfunction-Associated Steatohepatitis), where liver inflammation develops alongside fat accumulation. MASH increases the risk of fibrosis, cirrhosis, and liver failure.
One of the key drivers of MASLD is insulin resistance, which promotes the release of fatty acids into the bloodstream and encourages fat buildup in the liver.
So, why has fatty liver disease become so common? The answer largely lies in modern dietary patterns.
Drivers of Fatty Liver Disease
There are three main drivers of NAFLD:
#1: Fructose
Fructose doesn’t just contribute to higher carbohydrate intake, elevated blood glucose, and increased cholesterol levels; it also plays a significant role in the development of liver fat. In fact, some researchers have described fructose as a “weapon of mass destruction” when it comes to fatty liver disease.
Unlike glucose, which is used by cells throughout the body, fructose is metabolized in the liver, where it is converted into triglycerides that can accumulate and contribute to fatty liver.. Multiple studies show that high intake of fructose – particularly in the form of sugar-sweetened beverages – contributes to liver fat accumulation.
But what about fruit? While fruit does contain fructose, the amounts are usually small, unless you’re eating large quantities of high-sugar fruits like ripe bananas. The bigger issue is high-fructose corn syrup, commonly found in sodas, sweetened beverages, and processed foods. Cutting out high-fructose corn syrup is one of the most effective ways to reduce liver fat.
#2: Obesity and Insulin Resistance
The same dietary factors that contribute to fatty liver also play a central role in the development of obesity. Ultra-processed foods that are high in sugar and refined carbohydrates promote insulin resistance, a condition that underlies not only obesity, but also type 2 diabetes and MASLD.
Insulin resistance occurs when the body’s cells become less responsive to insulin’s effects. In response, the pancreas produces more insulin to keep blood sugar in check. Over time, this leads to chronically elevated insulin levels, or hyperinsulinemia, which further worsens insulin resistance.
Insulin is a hormone that promotes fat storage, and when levels remain high, it becomes much easier to gain weight, particularly in the form of visceral fat. This type of fat accumulates around the organs and is strongly associated with metabolic dysfunction and the development of MASLD.
#3: Inadequate Choline
Choline is an essential nutrient that supports liver function by helping the body process and export fat. Insufficient choline can lead to fat accumulation in the liver by impairing phosphatidylcholine production, which is needed to export fat in the form of very low-density lipoprotein (VLDL) particles. Low intake, genetics, hormone levels, and gut bacteria can all reduce choline availability, increasing the risk of MASLD.
Unfortunately, most people don’t get enough choline in their diets. Eggs, particularly the yolks, are one of the richest sources, but they’re often avoided due to outdated concerns about dietary cholesterol. Beef liver is another excellent source, though not commonly consumed. Other good options include fish and dark-meat poultry, as well as shiitake mushrooms and caviar.
Can A Keto Diet Help with Fatty Liver?
A ketogenic diet is a high-fat, low-carbohydrate way of eating that’s well-known for promoting weight loss and improving metabolic health. On a ketogenic diet, carbohydrates are restricted to less than 10% of daily calories, while fat typically supplies 70% or more, and protein accounts for the remaining 20 to 25%. These macronutrient ratios support a state of ketosis, in which the body shifts from using glucose to relying primarily on ketones and fat for fuel.
While research on the ketogenic diet for MASLD is still emerging, early findings are promising. Clinical trial data suggest the following:
- In one study, two weeks of dietary intervention resulted in a 42% average reduction in liver triglycerides in people with NAFLD, with significantly greater reductions in those following a ketogenic diet (20 grams of carbs per day) compared to a calorie-restricted diet.
- In women with PCOS, liver dysfunction, and obesity, a 12-week ketogenic diet significantly improved liver function, reduced body weight and blood glucose, and resolved fatty liver in most participants, outperforming standard pharmacological treatment.
- In another study, a very low-calorie ketogenic diet (VLCKD) led to significantly greater weight loss, reductions in visceral fat, and liver fat compared to a standard low-calorie diet in patients with NAFLD over two months.
Although it may seem surprising that a high-fat diet could improve fatty liver, the mechanisms behind MASLD help explain why keto can be beneficial.
First, the ketogenic diet is very low in fructose, one of the primary contributors to liver fat accumulation.
Second, a well-formulated ketogenic diet emphasizes nutrient-dense, minimally processed foods while eliminating highly processed products.
Third, because insulin resistance and obesity are major contributors to MASLD, the ketogenic diet’s ability to improve insulin sensitivity and support fat loss makes it especially effective for addressing the root causes of the disease.
Lastly, choline-rich foods like eggs are embraced on a ketogenic diet, not avoided. Eggs, in particular, are an excellent source of both fat and choline, making them ideal for supporting liver health on a keto lifestyle.
The Final Word
The root causes of fatty liver are the same ones behind heart disease and type 2 diabetes. Research suggests that a well-formulated ketogenic diet may help reverse fatty liver, improve insulin sensitivity, and support liver health, partly due to its high choline content.
For more on low-carb approaches to MASLD, watch this insightful video featuring Dr. Jean-Marc Schwarz of Touro University California.
As always, speak with your healthcare provider before making major dietary changes.
