Understanding Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): Causes, Diagnosis & Treatment

If you’ve been diagnosed with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) or are concerned about your liver health, you’re not alone. MASLD is a surprisingly common condition, affecting an estimated one in every three people in the UK.
The good news? In its early stages, MASLD is often reversible. This definitive guide will walk you through everything you need to know, from its root causes and symptoms to how it’s diagnosed and the essential steps you can take to manage and even reverse the condition.

What Exactly is Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)?

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is the term for a range of conditions caused by a build-up of fat in the liver. It is called “metabolic dysfunction-associated” because it is linked to metabolic conditions such as insulin resistance, obesity, and type 2 diabetes, distinguishing it from alcohol-related liver disease.
A healthy liver should contain little or no fat. When fat makes up more than 5% of your liver’s weight, it is classified as a fatty liver (steatosis).

MASLD exists on a spectrum:

Simple Fatty Liver (Steatosis): A largely harmless build-up of fat with little to no inflammation. This is the most common type.
Metabolic Dysfunction-Associated Steatohepatitis (MASH): A more serious form where the fat build-up is accompanied by liver inflammation and cell damage. MASH can lead to scarring of the liver (fibrosis).

Fibrosis and Cirrhosis: Persistent inflammation leads to scarring (fibrosis). Over time, this can progress to cirrhosis, severe scarring and hardening of the liver that impairs its function. Cirrhosis is irreversible and can lead to liver failure and liver cancer.

What Causes MASLD? The Key Risk Factors

Experts do not know the exact cause, but MASLD is strongly linked to metabolic syndrome, a cluster of conditions that increase your risk of heart disease, stroke, and type 2 diabetes.

The primary causes and risk factors for MASLD include:

Insulin Resistance and Type 2 Diabetes: Your body doesn’t use insulin effectively, leading to high blood sugar and increased fat storage in the liver.
Obesity: Particularly carrying excess weight around the abdomen (an “apple” body shape). This is a leading risk factor.
High Cholesterol and Triglycerides: High levels of fats in your blood can contribute to fat accumulation in the liver.
Metabolic Syndrome: Having any three of the following — large waist size, high blood pressure, high triglycerides, low HDL (“good”) cholesterol, and high fasting blood sugar.
Polycystic Ovary Syndrome (PCOS): This condition is also linked to insulin resistance.
An Underactive Thyroid (Hypothyroidism): Can affect your metabolism and contribute to weight gain.

Rapid Weight Loss and Poor Diet: Diets high in sugar, processed foods, and saturated fats can promote fat storage in the liver.

Recognising the Symptoms of MASLD

One of the most challenging aspects of MASLD is that it is often a “silent” disease. In the early stages, most people experience no symptoms at all.

As the condition progresses to more advanced stages (like MASH or cirrhosis), symptoms may include:

A dull or aching pain in the top right of your abdomen (over your liver)
Persistent fatigue and weakness
Unexplained weight loss
Jaundice (yellowing of the skin and eyes)

If you experience any of these symptoms, it is crucial to consult your GP.

How is MASLD Diagnosed in the UK?

MASLD is often first suspected during routine blood tests or investigations for other conditions. The NHS diagnostic pathway typically involves:

Blood Tests (Liver Function Tests – LFTs): Elevated levels of liver enzymes like ALT and AST can indicate liver inflammation. However, it’s possible to have MASLD with normal liver enzyme levels.
Scans:
1. Ultrasound Scan: This is the most common initial scan. It uses sound waves to create an image of your liver and can detect excess fat.
2. FibroScan® (Transient Elastography): A specialised, non-invasive scan that measures liver stiffness, which indicates the level of fibrosis (scarring). This is a key tool for staging the disease.

Further Investigations: If advanced scarring (cirrhosis) is suspected, your consultant may recommend a liver biopsy, where a small sample of liver tissue is taken for analysis. This is less common due to the effectiveness of the FibroScan.

The Cornerstone of MASLD Treatment and Management

There is currently no specific medication licensed to treat MASLD in the UK. The primary and most effective treatment is lifestyle modification.

1. Weight Loss

This is the single most important intervention. The goal is gradual, sustained weight loss.

Aim to lose 5-10% of your body weight. For a person weighing 90kg (14 stone), this means losing 4.5-9kg (10-20 pounds).
Losing just 5% of your body weight can reduce liver fat significantly. Losing 10% can improve inflammation and potentially reverse some fibrosis.

2. Adopt a Healthy, Balanced Diet

Focus on a Mediterranean-style diet, which is highly recommended by NHS dieticians.

Eat more: Fruits, vegetables, whole grains (oats, brown rice), and lean protein (fish, poultry, pulses).
Choose healthy fats: Found in olive oil, nuts, seeds, and avocados.
Avoid: Sugary drinks, processed foods, refined carbohydrates (white bread, pasta), and excessive saturated fats.

3. Get Regular Physical Activity

Aim for at least 150 minutes of moderate-intensity exercise per week (e.g., brisk walking, cycling, swimming).
Incorporate strength training (e.g., weight lifting, resistance bands) at least twice a week. Exercise helps improve insulin sensitivity, even without significant weight loss.

4. Manage Underlying Conditions

Work with your GP to effectively manage:

Type 2 Diabetes
High Blood Pressure
High Cholesterol

Frequently Asked Questions About MASLD

Q1. Can MASLD be reversed?

Yes. In the early stages (simple fatty liver and even early MASH), the damage can often be completely reversed through sustained lifestyle changes, particularly weight loss.

Q2. Is MASLD serious?

Simple fatty liver is not typically serious on its own. However, if it progresses to MASH and then cirrhosis, it becomes a serious condition that can lead to liver failure. This is why early diagnosis and management are critical.

Q3. Are there any foods I should definitely avoid?

Yes. The most important items to cut down on are sugary drinks (fizzy drinks, squashes, fruit juices) and highly processed foods (ready meals, sugary snacks, processed meats).

Q4. Can a slim person get MASLD?

Yes. This is known as “lean MASLD.” People of a normal weight can still have the condition if they have insulin resistance or a genetic predisposition.