MASLD vs NAFLD: What the New Fatty Liver Name Means

TL;DR

• In 2023, liver societies renamed NAFLD to MASLD (metabolic dysfunction-associated steatotic liver disease) and NASH to MASH. A new category, MetALD, covers people with MASLD who also drink more than a light amount of alcohol.
• MASLD is diagnosed by fat in the liver plus at least one of five cardiometabolic risk factors, instead of by ruling out alcohol.
• For about 99% of patients, it’s the same disease with a new name. The research, targets and treatment advice all carry over.

MASLD and NAFLD describe the same condition for almost everyone who has it. MASLD (metabolic dysfunction-associated steatotic liver disease) is simply the newer, more accurate name for what used to be called NAFLD (nonalcoholic fatty liver disease), and MASH replaced NASH for the inflamed form.

What did change is how the disease is defined. NAFLD was diagnosed by excluding things, mainly heavy drinking. MASLD is diagnosed by what’s actually present: fat in the liver along with at least one sign of metabolic dysfunction, like excess weight, raised blood sugar or high blood pressure. If your older records say NAFLD and your newer ones say MASLD, nothing about your liver changed. Here’s what the new terms mean and why the switch matters for you.

What Do MASLD, MASH and MetALD Stand For?

The new names were published in June 2023 in a consensus statement led by the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL), with the Latin American liver association (ALEH).

Old term	New term	What it means
Fatty liver (general)	SLD: steatotic liver disease	The umbrella term for any excess fat in the liver, whatever the cause
NAFLD: nonalcoholic fatty liver disease	MASLD: metabolic dysfunction-associated steatotic liver disease	Liver fat plus at least one cardiometabolic risk factor
NASH: nonalcoholic steatohepatitis	MASH: metabolic dysfunction-associated steatohepatitis	The inflamed form, with liver cell injury, which can lead to scarring
No clear equivalent	MetALD: metabolic and alcohol-related liver disease	MASLD plus moderate-to-heavy drinking
Alcoholic liver disease	ALD: alcohol-related liver disease	Liver disease driven mainly by alcohol

“Steatotic” is the medical word for fatty (from steatosis, fat buildup). “Steatohepatitis” (fat plus inflammation) was kept on purpose: the experts felt it’s an important concept worth preserving, so NASH became MASH rather than disappearing.

Why Was NAFLD Renamed?

The rename came out of a multi-year process involving 236 panelists from 56 countries, including liver experts and patient advocates. Decisions needed a 67% supermajority. The main problems they identified:

• The old name defined the disease by what it wasn’t. “Nonalcoholic” told you the cause was not alcohol, but not what the cause was. The real drivers, insulin resistance, excess weight, type 2 diabetes and abnormal blood fats, weren’t in the name at all.
• The words felt stigmatizing. In the survey, 61% of respondents felt “nonalcoholic” was stigmatizing and 66% felt the same about “fatty.”
• The old definition left people out. People with metabolic risk factors who also drank moderately didn’t fit neatly into NAFLD or alcohol-related liver disease, so they were often excluded from research.

Overall, 74% of respondents felt the old nomenclature was flawed enough to change. The new name puts the cause, metabolic dysfunction, front and center, and the AASLD describes it as an “affirmative, non-stigmatizing name and diagnosis.”

What Are the MASLD Diagnostic Criteria?

To be diagnosed with MASLD, an adult needs fat in the liver (usually seen on imaging) plus at least one of these five cardiometabolic criteria:

Criterion	Threshold for adults
1. Weight or waist	BMI of 25 or higher (23 or higher in Asian populations), or waist circumference over 94 cm / 37 in (men) or 80 cm / 31.5 in (women)
2. Blood sugar	Fasting glucose of 100 mg/dL (5.6 mmol/L) or higher, or 2-hour glucose of 140 mg/dL (7.8 mmol/L) or higher, or HbA1c of 5.7% or higher, or type 2 diabetes, or treatment for it
3. Blood pressure	130/85 mmHg or higher, or taking blood pressure medicine
4. Triglycerides	150 mg/dL (1.70 mmol/L) or higher, or on lipid-lowering treatment
5. HDL cholesterol	40 mg/dL (1.0 mmol/L) or lower in men, 50 mg/dL (1.3 mmol/L) or lower in women, or on lipid-lowering treatment

Children and teens have their own criteria, set separately.

Two things follow from this list. First, the bar is low: prediabetes-range blood sugar or a BMI of 25 is enough. That’s why almost everyone previously diagnosed with NAFLD qualifies. Second, you don’t have to be overweight to have MASLD. A person with a normal BMI who has high triglycerides or prediabetes can meet the criteria, which is sometimes called “lean MASLD.”

If someone has liver fat but none of the five criteria and no other known cause, it’s classified as cryptogenic steatotic liver disease, meaning the cause is unknown for now.

What Is MetALD?

MetALD is the most genuinely new part of the system. It describes people who meet the MASLD criteria and drink more than a light amount of alcohol:

Category	Women	Men
MASLD	Under 140 g alcohol/week (fewer than about 10 US drinks)	Under 210 g/week (fewer than about 15 drinks)
MetALD	140–350 g/week (about 10–25 drinks)	210–420 g/week (about 15–30 drinks)
ALD (alcohol-related)	Above 350 g/week	Above 420 g/week

Drink counts use the US standard drink of 14 grams of pure alcohol: 12 oz of regular beer, 5 oz of wine or 1.5 oz of spirits (NIAAA). Real pours are often bigger than a standard drink, so these counts can underestimate what’s in the glass.

Why this matters: under the old system, a person with obesity and diabetes who drank a couple of drinks most days had no good home. They weren’t “nonalcoholic,” but alcohol wasn’t clearly the only cause either. MetALD recognizes that metabolic dysfunction and alcohol often act together on the liver. It also sends a clear message: in someone with MASLD, the alcohol counts.

Being under the MetALD range doesn’t mean alcohol is harmless for a fatty liver. The AASLD says people with significant fibrosis (F2 or higher) should not drink at all. Read more in is alcohol safe with fatty liver?

The Steatotic Liver Disease Family

It helps to see the full umbrella. Steatotic liver disease (SLD) includes:

• MASLD, with MASH as its inflamed subtype
• MetALD, metabolic dysfunction plus moderate-to-heavy alcohol use
• ALD, alcohol-related liver disease
• SLD with a specific cause: liver fat due to another identifiable condition, such as hepatitis C, celiac disease or rare inherited conditions like Wilson disease
• Cryptogenic SLD, liver fat with no metabolic risk factors and no known cause

The point of the umbrella is to name the driver, because the driver guides treatment.

How is MASH different from MASLD?

MASH isn’t a separate disease. It’s the more active form of MASLD: fat in the liver plus inflammation and injury to liver cells. That ongoing injury is what can drive scarring (fibrosis) over time. A review in American Family Physician estimated that about one-third of people with the old NAFLD diagnosis had NASH.

Confirming MASH has traditionally required a liver biopsy, because blood tests and standard imaging can’t reliably see inflammation. In everyday care, doctors focus less on proving MASH and more on estimating scarring with FIB-4 and FibroScan, since fibrosis stage is what best predicts how the liver will do. It also decides treatment: the two medicines approved in the US for this condition are for MASH with moderate to advanced fibrosis (stages F2–F3), not for liver fat alone.

Is MASLD the Same Disease as NAFLD?

For practical purposes, yes. A Swedish study of more than 1,300 patients with confirmed NAFLD, published in the Journal of Hepatology, found that 99% met the new MASLD criteria. The authors concluded that the natural history is identical, so decades of NAFLD research still apply.

The AASLD says the same thing in its own words: the new SLD nomenclature “does not alter natural history, clinical trials or biomarkers.” In other words:

• The weight-loss targets are unchanged: the 2024 European guideline aims for at least 5% loss to reduce liver fat, 7–10% to improve inflammation and 10% or more to improve fibrosis.
• The tests are unchanged: ALT, FIB-4, FibroScan and, occasionally, biopsy.
• The diet advice is unchanged: a Mediterranean-style pattern, few sugary drinks, limited ultra-processed food. See our fatty liver diet guide.
• Studies labeled NAFLD or NASH still apply to MASLD and MASH.

What about MAFLD?

You may also see MAFLD (metabolic dysfunction-associated fatty liver disease) in some reports. It was a different name proposed in 2020 by an international expert group, with its own criteria: liver fat plus overweight or obesity, type 2 diabetes, or at least two of seven metabolic risk markers. MAFLD and MASLD overlap heavily but aren’t identical. The major US and European liver societies adopted MASLD, which is the term used in current AASLD and EASL guidance.

Why the New Name Matters for Patients

A name change can sound cosmetic, but it shifts how the disease is thought about, and that can change your care.

1. It connects your liver to your heart and metabolism. Because MASLD is defined by cardiometabolic risk factors, the diagnosis itself points to the rest of your health. That matters: according to the AASLD, the most common causes of death in people with fatty liver are cardiovascular disease and non-liver cancers, followed by liver disease. A MASLD diagnosis is a good reason to check blood pressure, blood sugar and cholesterol, and to treat them.

2. It’s a positive diagnosis, not a leftover. You no longer get a label that means “fat in the liver, cause unclear, not alcohol.” You get a name that says why.

3. It takes alcohol seriously. MetALD makes it explicit that moderate drinking and metabolic risk add up. If you drink regularly, expect your doctor to ask about it and to count it.

4. It may reduce stigma. Dropping “fatty” and “nonalcoholic” was specifically meant to make the diagnosis easier to talk about. Less shame can mean people raise it with their doctors sooner.

5. It explains mixed labels. You’ll see both old and new terms for a while. The FDA’s March 2024 approval of resmetirom (Rezdiffra) described the condition as noncirrhotic NASH, while the August 2025 approval of semaglutide (Wegovy) for this use described it as noncirrhotic MASH. Both refer to the same disease.

What Should You Do If Your Chart Still Says NAFLD?

Nothing urgent. Your records don’t need to be “fixed” for your care to be right. What’s worth doing is making sure the follow-up matches what the guidelines recommend:

1. Ask about your fibrosis risk. The key question isn’t the name, it’s how much scarring there is. Ask for your FIB-4 score and whether you need a FibroScan. Our guide to ALT and AST levels in fatty liver explains these numbers.
2. Check which of the five criteria apply to you. Knowing whether it’s your weight, blood sugar, blood pressure or lipids tells you where to focus.
3. Be honest about alcohol. It decides whether you have MASLD or MetALD, and it matters most if you have scarring.
4. Treat the metabolic drivers. Weight loss if needed, activity, and managing diabetes, cholesterol and blood pressure. Tracking what you eat for a few weeks helps; an app like Liverly can scan a meal and flag the added sugar and saturated fat.
5. Know what improvement looks like. Our guide on how to reverse fatty liver covers the targets, tests and timelines.

If you’ve been told you have cirrhosis, the nutrition priorities are different. See our cirrhosis diet guide.

The Bottom Line

MASLD is the new name for NAFLD, and MASH is the new name for NASH. For about 99% of patients, it’s the same condition, and everything we know about treating it still applies. The difference is in the definition: MASLD is diagnosed by liver fat plus at least one cardiometabolic risk factor, so the name now points to the real cause. MetALD covers people whose metabolic risk and moderate drinking both play a part. For you, the practical upshot is the same as it always was: know your fibrosis risk, treat your weight, blood sugar, cholesterol and blood pressure, and keep alcohol low or at zero.

Sources

• Rinella et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature (Journal of Hepatology 2023)
• AASLD: New MASLD Nomenclature
• Hagström et al. 99% of patients with NAFLD meet MASLD criteria and natural history is therefore identical (Journal of Hepatology 2024)
• AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease (Rinella et al., Hepatology 2023)
• NIAAA Rethinking Drinking: What is a standard drink?

This article is for informational purposes only and is not medical advice. Talk to your doctor or hepatologist about your specific situation.