In the last post, I mentioned that visceral fat often doesn't just sit near the liver — it infiltrates it. This post is about that condition specifically: what it actually is, how it's diagnosed, how it progresses, and why I think it deserves far more attention than it typically gets.
A name that recently changed, for good reason
If you've read about this condition before, you may know it as NAFLD (non-alcoholic fatty liver disease) or, in its more severe form, NASH (non-alcoholic steatohepatitis). In 2023, the medical community formally updated this terminology, with the change endorsed by liver and metabolic disease specialists across dozens of countries. The new names are MASLD (metabolic dysfunction-associated steatotic liver disease) and MASH (metabolic dysfunction-associated steatohepatitis).
This wasn't a cosmetic rebrand. The old naming defined the condition by what it wasn't — not caused by alcohol — which is both stigmatizing and imprecise. The new naming defines it by what it actually is: a condition driven by metabolic dysfunction. That's a more accurate description, and it ties the disease directly to the same underlying drivers I've been describing throughout this series — insulin resistance, visceral fat, and the broader metabolic disease picture.
What MASLD actually is
MASLD is diagnosed when there's excess fat accumulation within liver cells — confirmed through imaging or, less commonly now, biopsy — alongside at least one cardiometabolic risk factor: excess weight, elevated blood sugar or prediabetes, elevated blood pressure, or abnormal lipid levels. In practice, this means MASLD is closely linked to the same conditions I've already covered: obesity, metabolic syndrome, and visceral fat accumulation specifically.
It's also strikingly common. Current estimates suggest roughly a third of adults have some degree of MASLD, and the number is meaningfully higher among patients who already have obesity or metabolic syndrome. Most of these patients have no idea. MASLD is frequently silent — it typically produces no symptoms until the disease has progressed significantly, which is part of why I think it deserves more attention in a general conversation about metabolic health than it usually gets.
How it can progress
MASLD on its own — fat accumulation without significant inflammation or cell damage — is the earlier, less severe stage of this disease. In a meaningful subset of patients, it progresses to MASH, where the fat accumulation is accompanied by active inflammation and liver cell injury. This is the stage where real damage starts accumulating.
From there, sustained inflammation can lead to fibrosis — scarring of liver tissue, which is staged on a scale from F0 (no scarring) to F4 (cirrhosis, the most advanced and least reversible stage). Fibrosis stage, not the amount of fat itself, is what actually determines a patient's long-term risk of serious complications, including liver failure and liver cancer. This is a critical distinction: a patient can have a significant amount of fat in the liver with relatively little fibrosis, and a different patient can have progressed to serious fibrosis. Fibrosis staging, not simply the presence of fatty liver, is what determines how seriously a case needs to be treated.
How this is diagnosed
Diagnosis has become considerably less invasive in recent years. Ultrasound and specialized imaging techniques can identify liver fat directly. Elastography — a noninvasive technique that measures liver stiffness as a proxy for fibrosis — has become a standard tool for estimating fibrosis stage without requiring a liver biopsy in most patients. Biopsy remains the most definitive tool, particularly in more complex or advanced cases, but it's no longer the only path to a meaningful diagnosis.
Where treatment stands right now
This is an area that's evolved meaningfully in the last two years, and I want to describe it honestly rather than overstate where things are. For a long time, treatment was limited to lifestyle intervention — weight loss, dietary change, and in appropriate candidates, bariatric surgery — because no medication had been specifically approved for the disease itself.
That changed in 2024, when the FDA granted approval to a liver-targeted medication for patients with MASH and moderate-to-advanced fibrosis, specifically for use alongside diet and exercise, not as a replacement for them. Around the same time, GLP-1 medications — the same class I've written extensively about elsewhere on this site — have also shown meaningful benefit for liver fat and fibrosis in clinical trials, which is part of why I think of MASLD and MASH treatment as another place where GLP-1 therapy's benefits extend well beyond weight loss alone.
I want to be direct about where this stands: these are genuinely promising, relatively recent developments, not decades-established standards of care. The evidence is real, but this remains an active, evolving area, and treatment decisions here should be made individually with a provider who's tracking the current state of the field closely.
What I'd want you to take from this
Fatty liver disease is one of the clearest, most concrete illustrations of why visceral fat matters as much as I've described throughout this series. It's common, it's frequently silent, and it's a direct, measurable consequence of the same underlying metabolic dysfunction I've spent this whole series describing. If you have risk factors — visceral fat, metabolic syndrome, insulin resistance — it's worth asking your provider directly whether liver-specific evaluation makes sense, rather than assuming it would have shown up on a standard exam already. Often, it wouldn't have.
Curious whether your own liver health has ever been specifically evaluated? [Reach out / subscribe / etc. — placeholder for your CTA.]
Medical disclaimer: This content is provided for general educational and informational purposes only and does not constitute medical advice. It is not intended to diagnose, treat, cure, or prevent any condition, and it does not create a physician-patient relationship. Every patient's medical history, health status, and treatment needs are different. Always consult your own physician or qualified healthcare provider before starting, stopping, or changing any medication or treatment, and before making any decisions based on information found here. If you are experiencing a medical emergency, call 911 or go to your nearest emergency room.