MASLD, MetALD, ALD: Defining Conditions

Hepatologists Robert Fontana, MD, Manal Abdelmalek, MD, and JP Arab, MD, clarify how MASLD differs from MetALD and ALD, and how amounts of alcohol consumed can lead to progression of fibrosis.

Robert Fontana, MD, is a professor of medicine and director of the Transplant Hepatology Fellowship Program at University of Michigan Medicine in Ann Arbor, Michigan. Manal Abdelmalek, MD, FAASLD, is a professor of medicine and director of the Metabolic Dysfunction Associated Steatotic Liver Disease (MASLD) Clinical Research Program at Mayo Clinic in Rochester, Minnesota. Juan Pablo Arab, MD, is associate professor of medicine and the inaugural director of Alcohol Sciences at the Stravitz-Sanyal Institute for Liver Disease and Metabolic Health at Virginia Commonwealth University (VCU) Health in Richmond, Virginia.

Distinguishing MASLD, MetALD, and ALD in 2026

• MASLD involves liver steatosis associated with metabolic dysfunction; MetALD combines metabolic dysfunction with increased alcohol consumption; ALD is associated with heavy alcohol consumption.
• MetALD thresholds discussed were approximately 140 g of alcohol per week for women and 210 g per week for men. The speakers cautioned that these cutoffs may not capture all alcohol-related risk.
• In GI and liver practice, obtain an alcohol history and consider screening for alcohol use disorder. PEth testing can help assess and track alcohol consumption, but it does not measure liver disease severity.

Dr Fontana

So let's talk about though 2026. We know about BMI. It's been around, I think most of us measure that in a GI clinic. Maybe JP, tell us what is the distinction between MASLD, MET ALD and ALD? I think we're in a little bit of a quandary with differentiating those and why it matters.

Dr Arab:

Correct. So I think first from a conception point of view is MASLD is the disease where you accumulate fat in the liver. So steatosis secondary to metabolic dysfunction. So either diabetes, obesity or metabolic syndrome. ALD, so alcohol-associated liver disease is the one that is secondary to heavy alcohol consumption and it can also present as esteatosis. So that's I think the beauty of the new definition where before we were thinking of these two entities as a completely different entities, but now we understand that, especially in primary care or even in GI practices, the patient may present it with an ultrasound with esteatosis, and that's the real starting point or elevated liver enzymes. And patients will not always be straightforward the first visit on how much they are drinking. So I think that's kind of the starting point. So we have fatty labor. And then there is a third entity that is actually the combination between metabolic dysfunction and higher alcohol consumption and how alcohol and cardiometabolic risk factor interacts.

So the specific thresholds needed to be there because we needed a specific definition. Whether those thresholds are absolute truth, we don't know. I think mounting evidence is showing that probably thresholds are lower of what we thought before. As the nomenclature stands today in 2026 is if you are women, you are drinking more two drinks per day, so it's 140 grams per week or more than three. If you are men and you're drinking more than three drinks per day, so 210 grams per week, then you go to the meth ALD side and almost double of that you go to the ALD definition. How the NAAA or the NIH defined heavy alcohol consumption is actually more than one drink per day for women and two drinks per day for men. So you can guess that gray zoning in between is not very clear, but the current definition, if you need to go home today and remember something when I should be concerned, I will say if someone is drinking more than two drinks per day, so let's say 140 per week, probably for women you are in the met ALD by the nomenclature.

And for men and women, you are in the heavy drinker category for NAAA. So it's when you probably need to start digging more deeply on alcohol consumption, trying to identify alcohol use disorder as a screening tool and maybe trying to diagnose someone with an alcohol use disorder.

Dr Fontana:

So that's largely all based upon history and accuracy and so on, but it has prognostic significance because the more alcohol consumption, the more in addition to steatosis, you can get fibrosis. So Manal, tell me, a lot of us, maybe we don't have as much time to get into a deep alcohol history in the outpatient clinic. What's the role of serum biomarkers like PEth or urine tests? Do you use those to help you with these three categories of mast cell, met ALD and ALD? Where do those fit in addition to history of consumption?

Dr Abdelmalek:

Yeah, I do perform PEth testing in my clinical practice as a screening tool for concomitant alcohol use and also potentially as a prognostic tool currently. I tell my patients that this is the same type of assay that I would otherwise order if I was considering any cofactor that can accelerate their disease progression, whether I'm evaluating iron or the overlap with autoimmune hepatitis, that alcohol fortunately is a modifiable risk factor that we could work on. And it also helps me discern, as JP was saying, whether they fall into that category of MetALD and why is that so important for me? Because those patients with MetALD with moderate to more significant alcohol use in the context of their metabolic syndrome will potentially have more accelerated fibrosis progression and shortened natural history of disease and some data to suggest that they could be at higher risk for hepatic decompensation.

So I do believe my patients, but I do validate with some tangible markers and I use that potentially to say, okay, your PEth test was this value. Let's see if we can work on that and bring that down at the time of your next visit. And it can be used to even reinforce behavior.

Dr Fontana:

So I think GI docs are probably, we're a little more versed with alcohol. We've seen a lot of it in our training and in our careers, probably even maybe more so than cardiometabolic risk factors of managing dyslipidemia and hypertension. So I think it's somewhat intuitive to the average GI doc to ask about alcohol and then have an objective biomarker. And the thing I like about PEth is it's a continuous number, like you say, and it's quantitative, but semi-quantitative categorically, like saying a little, medium, or a lot. And I use it all the time, I agree in all my liver patients, whether they're MASLD, hemochromatosis, what have you. So it's a useful tool, but I think to the audience here, it in and of itself is a secondary biomarker of consumption of alcohol. It doesn't tell you how bad the liver is.