MASH Explained: The Silent Liver Condition That Could Be Fueling Your Weight Struggles

Key Takeaways

• Metabolic dysfunction-associated steatohepatitis (MASH) is the inflammatory form of fatty liver disease; it can progress for years without symptoms, yet still lead to fibrosis and cirrhosis. 
• Liver health and metabolism are tightly linked. MASH worsens insulin resistance, disrupts hormone balance, and depletes energy, making blood sugar control and overall metabolic health more challenging to manage. 
• Early detection and lifestyle modifications are crucial for effective management.

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Liver disease can be scary, and it's usually not our first thought when we think about stubborn weight gain. But an emerging condition called metabolic dysfunction-associated steatohepatitis, or MASH, is changing that conversation. 

Previously referred to as nonalcoholic steatohepatitis (NASH), MASH is now recognized as part of the broader spectrum of metabolic dysfunction-associated steatotic liver disease (MASLD) and is more common than many realize. 

MASH is a type of fatty liver disease, often seen alongside obesity, type 2 diabetes, and metabolic syndrome, that is closely tied to liver fat buildup, fibrosis, and eventual cirrhosis if left unchecked. Essentially, our liver health can deteriorate silently, without dramatic symptoms, and can progress for years before it’s detected. It may be quietly contributing to insulin resistance and long-term metabolic dysfunction.¹ 

We will explain what MASH is, how it differs from other liver conditions, such as NAFLD and NASH, and why supporting liver health could be a missing link in your metabolic picture. 

What Is MASH (Metabolic Dysfunction-Associated Steatohepatitis)? 

MASH stands for metabolic dysfunction-associated steatohepatitis. It’s a type of fatty liver disease that occurs when fat accumulates in the liver, leading to inflammation and metabolic damage. This is why MASH is often called a “silent liver disease” as it can quietly worsen for

years without clear warning signs. Over time, this can lead to liver scarring (also called fibrosis), non-alcoholic cirrhosis, or even liver failure in extreme cases that aren’t treated.¹ 

MASH is part of a group of conditions now called metabolic dysfunction-associated steatotic liver disease (MASLD), a new term that replaces what used to be known as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH).¹

Here’s a quick breakdown of these different terms: 

• NAFLD is the starting point. It means there’s fat in the liver, but no inflammation or damage yet. And this damage and fat buildup does not come from excessive alcohol, but rather lifestyle choices. 
• NASH (now called MASH) happens when that fat causes inflammation and starts to harm the liver cells. 
• MASH is the newer name that shows how closely this condition is connected to metabolic issues like obesity, type 2 diabetes, and insulin resistance. 

One of the biggest concerns with MASH is that it often develops with no obvious symptoms. Often, people are unaware they have fat deposits in their liver until it’s detected during routine blood tests or imaging for another purpose. 

How MASH Affects Your Metabolism and Weight 

You might not think your liver has much to do with your metabolism, but your liver impacts your blood sugar, insulin, and hormone levels. Let’s examine our liver physiology to understand how fatty buildup in the liver can begin to impact our metabolic health.¹

• Insulin Resistance: When doctors diagnose MASH in the liver, one of the first symptoms to show up is insulin resistance. A damaged liver has trouble responding to insulin, which means sugar stays in the bloodstream longer, and the liver may release extra glucose along with fat, like triglycerides. That extra fuel is quickly tucked away as liver fat or abdominal fat, driving weight gain, insulin resistance, and a higher risk of type 2 diabetes or metabolic syndrome. 
• Hormonal Disruption: Stress on our liver also impacts our hormones. The liver normally clears hormones that impact our appetite, stress levels, and how we store fat. With a liver that has excessive fatty tissue, these hormones can shift, making you feel hungrier, store more calories through fat, and change your cholesterol or triglyceride numbers. 
• Energy Regulation: A healthy liver can switch between burning carbohydrates and fat for fuel. MASH limits the liver's ability to flexibly shift its energy sources. This means that you may experience significant energy drops and fatigue between meals or have trouble controlling your blood sugar throughout the day.

Signs and Symptoms: Why MASH Is Often Missed 

Your liver works quietly. It has almost no pain-sensing nerves, so metabolic dysfunction-associated steatohepatitis can brew for years before you or your healthcare professionals notice. By the time clear red flags appear, fat buildup may have already pushed the organ toward later stages of liver disease. 

Here are some of the most common signs people report who develop MASH: 

• Fatigue 
• Unexplained weight gain 
• Mild upper abdominal discomfort 
• Blood sugar dysregulation 
• Energy crashes 
• High blood pressure 
• Rising triglycerides 
• Bloating after meals 

Because these signs are vague, many people attribute them to stress, aging, or hormonal changes instead of considering liver health first. Laboratory work often reveals the true story. Slightly elevated liver enzymes, rising triglycerides, or a hint of insulin resistance markers can also be early indicators. Additionally, a quick and painless FibroScan elastography test measures the stiffness of the liver, revealing scar tissue long before symptoms become noticeable. 

Left unchecked, silent liver inflammation can lead to dangerous scar tissue in the liver. And if untreated can result in end-stage problems like liver failure or liver cancer. Catching those subtle hints early gives you time to tackle risk factors such as type 2 diabetes, high cholesterol, or high blood pressure before they progress. 

Who Is at Risk for MASH? 

You may have noticed that the liver is very closely tied to blood sugar metabolism. That means that blood sugar, cardiovascular disease, and blood pressure all have a two-way relationship with the liver. 

Many of the lifestyle interventions and warning signs for other chronic conditions, like diabetes and heart disease, are also true for MASH.¹ 

• Carrying extra weight or having a higher BMI: Excess body fat, particularly around the waist, contributes to fatty liver disease and is associated with increased insulin resistance.
• Living with type 2 diabetes or prediabetes: Chronically high blood sugar signals the liver to store more fat, setting the stage for metabolic dysfunction-associated steatohepatitis. 
• Metabolic syndrome or high triglycerides/cholesterol: A cluster of risk factors, including high blood pressure, elevated fasting glucose, an enlarged waist, and abnormal lipids, can significantly increase the likelihood of liver fibrosis.
• Polycystic ovary syndrome (PCOS): Hormonal shifts and insulin resistance in PCOS raise the likelihood of MASH even in younger, leaner individuals. 
• Sedentary lifestyle: Sitting most of the day lowers calorie burn and encourages fat buildup in the liver. 

However, being overweight isn't necessarily an indicator. There is a subset of people who have a normal body mass index that still can develop fatty liver conditions if they have an unhealthy diet, low muscle mass, or a strong family history of liver disease. This is also known as “Lean MASH,” as the individuals who developed it don’t appear overweight. 

There is one additional unique population at risk of high fat deposits in the liver: individuals who lose weight rapidly, such as those on GLP-1s or those undergoing bariatric surgery. Sudden shifts in body weight can temporarily flood the liver with fat, so monitoring your weight loss pace is important. 

How to Support Your Liver and Metabolic Health 

Supporting liver health is central to slowing or even reversing metabolic dysfunction-associated steatohepatitis (MASH), depending on the stage you’re in. The following evidence-based steps can help you address the drivers of liver fat, inflammation, and insulin resistance. 

Nutritional Strategies 

• Mediterranean-style eating pattern: Emphasising extra-virgin olive oil, fish rich in omega-3s, and high-fiber plants like legumes, whole grains, nuts, and plenty of fruits and vegetables all support a healthy liver. These foods supply antioxidants and unsaturated fats that may lower liver fat and improve lipid profiles.² 
• Limit refined carbohydrates and added fructose: Reducing sugary drinks, sweets, and white flour products helps prevent sharp rises in blood glucose and triglycerides, and may potentially ease the metabolic load on the liver.³ 
• Time-restricted eating (if appropriate): A regular overnight fast of about 12 to 14 hours can enhance insulin sensitivity and encourage the body to use stored fat, including hepatic fat. Specifically, fasting while in a calorie deficit is the most effective approach here.⁴ 

Lifestyle Interventions 

• Moderate physical activity: Getting at least 150 minutes per week of brisk walking, cycling, or resistance training improves insulin action, reduces visceral fat, and helps slow progression toward fibrosis.⁵
• Reduce alcohol intake: Even moderate drinking can accelerate liver inflammation and scarring. Limiting or avoiding alcohol allows the liver to focus on repairing existing damage.⁶
• Consistent, adequate sleep: Seven to nine hours of quality sleep supports hormone balance, appetite regulation, and healthy blood pressure, all of which protect liver function.⁷

Supplements & Monitoring 

• Targeted supplements (with professional guidance): Milk thistle provides antioxidant compounds, omega-3 fatty acids can improve hepatic fat, and berberine may improve insulin resistance. These should be used only under the supervision of a qualified clinician, and may not be the right fit for everyone.⁸ 
• Routine laboratory and imaging follow-up: Request liver enzyme panels (ALT, AST) at regular check-ups and discuss non-invasive tools, such as FibroScan, when indicated. Early detection of rising enzymes or liver stiffness allows timely adjustments in treatment and lifestyle. 

When to Talk to Your Doctor 

If you live with type 2 diabetes, metabolic syndrome, or ongoing weight gain that does not respond to diet and exercise, schedule a visit with your primary-care physician. Early evaluation can identify MASH symptoms before they advance. 

In some cases, your physician may refer you to a gastroenterologist or hepatologist for a liver biopsy or enrollment in clinical trials of new therapies. Request screening sooner rather than later if you notice unexplained fatigue, upper-right abdominal discomfort, or steadily climbing triglycerides. 

Ask about these standard tests and imaging tools: 

• Liver enzyme panel (ALT and AST): Persistent elevations suggest inflammation or cell injury. 
• Ultrasound or MRI: These studies help determine the amount of fat stored in the liver and can help rule out other causes of liver disease. 
• FibroScan or other elastography: A painless bedside test that measures liver stiffness, which rises as scar tissue forms. 
• Additional blood tests: Fasting glucose, A1C, triglycerides, and cholesterol help identify insulin resistance and other metabolic risk factors. 

The Bottom Line 

MASH is a quiet but potentially serious liver condition that starts with a little fat buildup and can progress to scar tissue and liver failure if unchecked. Additionally, the symptoms can be vague, such as fatigue, and may be attributed to various causes, including natural aging. Get ahead of it by mentioning liver testing at your annual physical and work to implement lifestyle changes, such as adopting the Mediterranean diet and incorporating regular movement into your routine. 

Learn More With Signos’ Expert Advice 

Your liver and blood sugar levels work in tandem. Explore practical ways to strengthen both by learning how Signos can improve your health, and dive deeper into day-to-day glucose insights on Signos’ blog. Together, these resources offer science-backed guidance to help you build habits that support overall metabolic health.