Is the keto diet good for fatty liver?

A randomized trial published in Cell Metabolism in August 2026 compared three groups that each lost about 10% of body weight. The ketogenic diet reduced liver fat by 67%; the Mediterranean and very-low-fat plant-forward diets by 45%. The trial had 42 participants and all meals were provided by the research team.

Does the Mediterranean diet not work for fatty liver?

It does. In the same trial the Mediterranean diet cut liver fat by 45%. Keto produced a larger drop, but losing weight reduces liver fat whichever diet gets you there.

Doesn't eating a lot of fat on keto make the liver fattier?

This trial found the opposite. Part of the fat in the liver is made by the liver itself from surplus carbohydrate. When carbohydrate falls very low, insulin drops and the liver shifts to burning fat. The group eating 73% of calories from fat reduced liver fat the most.

I have fatty liver. Can I start keto without a doctor?

Not if you take diabetes medication (insulin, a sulfonylurea or an SGLT2 inhibitor), have liver fibrosis or cirrhosis, have gallbladder, pancreatic or kidney disease, or are pregnant or breastfeeding. Otherwise it is still sensible to have liver enzymes measured at the start and again after 8-12 weeks.

Health

Is Keto Good for Fatty Liver? What the 2026 Trial Found

8 min read · Health Guide · October 1, 2026

Short answer: yes. According to the newest controlled trial we have, it helps, and by more than two other diets producing the same weight loss. In a study published in Cell Metabolism on August 27, 2026, a ketogenic diet reduced liver fat by 67%; a Mediterranean diet and a very-low-fat plant-forward diet each managed 45%. But the trial had 42 participants, and every meal was supplied by the research team. Those two details change how you should read the result.

All three groups lost about 10% of their body weight. The difference showed up in liver fat and blood sugar control, not on the scale.

What Is Fatty Liver Disease (NAFLD / MASLD)?

Non-alcoholic fatty liver disease means excess fat building up in liver cells. For years it went by NAFLD; in 2023 specialist societies renamed it MASLD (metabolic dysfunction-associated steatotic liver disease). You may see either on a lab or ultrasound report, and they describe the same condition. It usually causes no symptoms and tends to appear alongside insulin resistance, prediabetes and fat around the waist.

What Exactly Did the 2026 Trial Do?

Samuel Klein's team at Washington University School of Medicine in St. Louis randomly assigned 42 people with obesity, prediabetes and fatty liver to one of three diets:

Ketogenic: 4% of calories from carbohydrate, 73% from fat
Mediterranean: 50% carbohydrate, 35% fat
Very-low-fat, plant-forward: 70% carbohydrate, 15% fat

What sets it apart is the design. Every meal was prepared and provided by the researchers, and participants met a dietitian weekly. The target in each group was a loss of about 10% of body weight, which took four to five months. So the usual objection, "keto did better because people lost more weight", was removed from the start: weight loss was matched, leaving diet composition as the variable.

The Results

Liver fat: Down 67% on keto, 45% in each of the other two groups.
Prediabetes: About half of the keto group went into remission, against 29% on the Mediterranean diet and 7% on the low-fat diet.
Insulin sensitivity: Improved in all three groups, with the largest improvement and the largest fall in blood insulin on keto.
Blood lipids: The keto group, which ate the most fat, showed no rise in blood fat or cholesterol.

That last point surprised the researchers too. First author Max Petersen called it "the most surprising finding". Klein's summary: if you have high liver fat and prediabetes, cutting carbohydrate can have metabolic effects beyond weight loss alone.

Why Would That Happen?

Part of the fat in your liver does not come from fat you eat. The liver makes it from surplus carbohydrate. When carbohydrate drops very low, insulin falls and the liver switches from making fat to burning it. The trial's finding that insulin fell most and glucagon rose most in the keto group fits that explanation. We cover the insulin side in more depth in our insulin resistance article.

What the Trial Does Not Show

It is small. Forty-two people split across three groups. The results are clear, but they need repeating in larger trials.
It is not real life. Meals were handed over ready-made. Holding 4% carbohydrate for four to five months in your own kitchen is a different job.
The other diets did not fail. A 45% reduction is a substantial improvement. Someone who loses the same weight on a Mediterranean diet is also helping their liver.
Long-term effects are unknown. The trial covers the weight-loss phase. There is no data on what liver fat does during maintenance or regain.
The cholesterol result does not generalize to everyone. Participants had obesity and were losing weight. Our LDL article covers the sharp LDL rise seen in some lean, athletic people on keto; that is a different picture from this trial.

Who Should Not Start Without a Doctor?

If you have a fatty liver diagnosis, you should already be under medical follow-up. Do not start keto on your own if:

You take medication for diabetes or prediabetes, especially insulin, a sulfonylurea or an SGLT2 inhibitor. When carbohydrate drops, doses need adjusting.
Your liver shows inflammation, fibrosis or cirrhosis beyond simple fat accumulation.
You have gallbladder, pancreatic or kidney disease.
You are pregnant or breastfeeding.

Having liver enzymes (ALT, AST), fasting insulin and a lipid panel measured before you start and again after 8-12 weeks is the most concrete way to see how the diet works for you. Our blood test article explains what each value means.

Sources: Petersen et al., "Effect of diet macronutrient content on the cardiometabolic response to weight loss: A randomized clinical trial", Cell Metabolism (August 27, 2026) · Cell Press news release (EurekAlert)

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