Treatment for hepatitis caused by obesity—medically termed non-alcoholic steatohepatitis (NASH) or metabolic dysfunction-associated steatohepatitis (MASH)—centres on addressing the underlying metabolic dysfunction that drives liver inflammation and damage. Whilst no medications are currently licensed in the UK specifically for NASH, effective management combines structured weight loss, dietary modification, increased physical activity, and optimisation of coexisting conditions such as type 2 diabetes and high cholesterol. For selected patients, weight-loss medications or bariatric surgery may be appropriate under specialist supervision. Early intervention can reverse liver fat accumulation, reduce inflammation, and prevent progression to cirrhosis.

Understanding Non-Alcoholic Fatty Liver Disease and Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD)—increasingly termed metabolic dysfunction-associated steatotic liver disease (MASLD)—occurs when excess fat accumulates in the liver despite minimal or no alcohol consumption. When this fat accumulation triggers inflammation and liver cell damage, the condition progresses to non-alcoholic steatohepatitis (NASH), now often called metabolic dysfunction-associated steatohepatitis (MASH). NAFLD affects approximately 25–30% of adults in the UK, with NASH developing in around 20% of those with fatty liver disease.

The underlying mechanisms involve complex metabolic dysfunction. Excess body fat, particularly around the abdomen, releases inflammatory substances and free fatty acids that overwhelm the liver's capacity to process lipids. This leads to fat toxicity, oxidative stress, and liver cell injury. Insulin resistance—a hallmark of obesity and type 2 diabetes—further increases fat deposition in liver cells. Over time, chronic inflammation can progress to scarring (fibrosis), cirrhosis, and liver cancer if left unmanaged.

Key risk factors include:

• Body mass index (BMI) above 30 kg/m²

• Type 2 diabetes mellitus

• Metabolic syndrome components (high blood pressure, abnormal cholesterol)

• Central obesity (waist circumference ≥94 cm in men of European origin, ≥80 cm in women; lower thresholds apply for people of South Asian, Chinese, and other ethnic backgrounds)

Many individuals have no symptoms in early stages, with diagnosis often occurring through abnormal liver blood tests or imaging. When symptoms do appear, they may include fatigue, discomfort in the right upper abdomen, or an enlarged liver. Importantly, normal liver blood tests do not exclude significant liver disease. NICE guidance emphasises that healthcare professionals should consider NAFLD in all patients with obesity, type 2 diabetes, or metabolic syndrome. This approach focuses on case-finding in high-risk groups rather than population screening, enabling timely intervention before irreversible liver damage occurs.

Medical Treatment Options for Non-Alcoholic Fatty Liver Disease

As of 2024, no medications are specifically licensed in the UK for treating NAFLD or NASH, making lifestyle modification the cornerstone of management. However, several therapeutic approaches target underlying metabolic dysfunction and associated health conditions. NICE recommends addressing cardiovascular risk factors and metabolic conditions as integral components of NAFLD treatment.

Management of coexisting conditions forms the foundation of medical therapy. For patients with type 2 diabetes, optimising blood glucose control is essential. Metformin, whilst not directly treating liver disease, improves insulin sensitivity and may indirectly benefit liver fat accumulation. Statins are recommended for managing abnormal cholesterol levels and should not be withheld due to NAFLD—evidence demonstrates their safety and cardiovascular benefit in people with fatty liver disease. Statins should be continued even if liver enzyme levels are mildly elevated, unless levels rise to more than three times the upper limit of normal. Blood pressure control using standard medications reduces overall metabolic risk.

Vitamin E supplementation (800 IU daily) and pioglitazone (a thiazolidinedione insulin sensitiser) have shown benefit in clinical trials, but NICE recommends these only for adults with biopsy-proven NASH under specialist supervision. Pioglitazone is contraindicated in heart failure and should be avoided in people with active bladder cancer or a history of bladder cancer. It carries risks including weight gain, fluid retention, bone fracture (particularly in women), and a potential bladder cancer signal. Vitamin E has been associated with increased risk of haemorrhagic stroke and prostate cancer in some studies, limiting its long-term use.

Emerging therapies under investigation include GLP-1 receptor agonists (such as semaglutide and liraglutide), which show promise in reducing liver fat and inflammation whilst promoting weight loss. Patients should be referred to hepatology services when advanced fibrosis is suspected (based on non-invasive tests) or when specialist input is required for complex cases. Treatment decisions should be individualised, considering the severity of liver disease, coexisting conditions, and patient preferences. All patients should be advised to report suspected side effects via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk.

Lifestyle Changes and Weight Management Strategies

Weight reduction remains the most effective intervention for NAFLD and NASH, with evidence demonstrating that sustained weight loss can reverse liver fat accumulation, reduce inflammation, and even improve scarring. NICE guidelines recommend a target weight loss of 7–10% of body weight to achieve meaningful improvement in liver inflammation, with greater benefits observed with losses exceeding 10%.

Dietary modification should focus on reducing overall calorie intake whilst improving nutritional quality. A Mediterranean-style diet—rich in vegetables, fruits, whole grains, legumes, nuts, and olive oil—has shown particular benefit for liver health. Patients should limit refined carbohydrates, added sugars (especially fructose-containing beverages such as soft drinks and fruit juices), and saturated fats. Portion control and mindful eating practices help establish sustainable habits. Referral to a registered dietitian provides personalised guidance and ongoing support.

Physical activity plays a crucial role beyond calorie expenditure. Regular exercise improves insulin sensitivity, reduces liver fat content, and decreases inflammation even without significant weight loss. UK Chief Medical Officers recommend at least 150 minutes of moderate-intensity aerobic activity weekly (such as brisk walking or cycling), combined with muscle-strengthening activities on two or more days per week. Activities should be tailored to individual fitness levels and preferences to enhance long-term adherence. Even modest increases in activity—such as brisk walking for 30 minutes daily—confer metabolic benefits.

Behavioural support significantly improves outcomes. Structured weight management programmes, whether delivered through NHS Tier 3 specialist services, commercial providers, or digital platforms, offer accountability and practical strategies. Cognitive behavioural techniques address emotional eating, stress management, and motivation. For individuals with BMI ≥40 kg/m² (or ≥35 kg/m² with significant comorbidities such as type 2 diabetes), bariatric or metabolic surgery may be considered following specialist assessment via Tier 3 or Tier 4 weight management services. Lower BMI thresholds (≥30 kg/m²) may apply for people of Asian family origin or for those with recent-onset type 2 diabetes. Surgery can produce substantial and sustained improvements in liver disease, but requires careful shared decision-making regarding risks and benefits.

Medications Used to Support Weight Loss in Fatty Liver Disease

Whilst no drugs are approved specifically for NASH treatment, several medications targeting obesity and metabolic dysfunction may support weight loss and indirectly benefit liver health. Pharmacological weight loss agents may be appropriate for selected patients, but access on the NHS is restricted and typically requires referral to specialist Tier 3 weight management services. NICE has defined specific eligibility criteria and treatment durations for these medicines.

Orlistat, a lipase inhibitor that reduces dietary fat absorption, is available both on prescription and over-the-counter (as alli 60 mg). It produces modest weight loss (typically 3–5% body weight) when combined with a reduced-calorie diet. Common side effects include gastrointestinal symptoms such as oily stools, flatulence, and faecal urgency, which can be minimised by following a low-fat diet (no more than 30% of calories from fat). Orlistat is contraindicated in cholestasis (bile flow obstruction) and chronic malabsorption syndromes. It may reduce absorption of fat-soluble vitamins; if supplementation is needed, a multivitamin should be taken at bedtime, at least two hours after the orlistat dose. Orlistat interacts with several medicines including ciclosporin, warfarin, levothyroxine, and some antiepileptic drugs—patients should inform their doctor or pharmacist of all medicines they are taking. Treatment should be stopped after 12 weeks if weight loss is less than 5% of initial body weight.

GLP-1 receptor agonists, including liraglutide 3.0 mg daily (Saxenda) and semaglutide 2.4 mg weekly (Wegovy), have demonstrated significant weight loss and reductions in liver fat content. These medications enhance feelings of fullness, slow stomach emptying, and improve blood glucose control. On the NHS in England, semaglutide is available via specialist weight management services for adults with at least one weight-related comorbidity and BMI ≥35 kg/m² (or ≥32.5 kg/m² for people from minority ethnic groups with a higher risk of comorbidities), for up to two years. Liraglutide has similar but slightly different access criteria. Common side effects include nausea, vomiting, and diarrhoea, typically diminishing over time. These agents are administered via subcutaneous injection. Patients should seek urgent medical attention if they develop severe abdominal pain, persistent vomiting, or signs of pancreatitis or gallbladder disease. Treatment should be stopped if adequate response is not achieved within the timeframe specified in the product information (typically 16 weeks for liraglutide, 24 weeks for semaglutide).

Patients should understand that medication is not a substitute for lifestyle modification but rather an adjunct to enhance weight loss efforts. Regular monitoring of liver function tests, lipid profiles, and blood glucose is essential. Individuals experiencing severe abdominal pain, persistent vomiting, jaundice, or signs of liver deterioration should seek immediate medical attention, as these may indicate serious complications requiring urgent assessment.

Monitoring and Long-Term Management of Liver Health

Regular monitoring is essential for assessing disease progression, treatment response, and identifying complications early. NICE recommends using the Enhanced Liver Fibrosis (ELF) blood test as the initial assessment for advanced fibrosis in people with NAFLD. Some local pathways may use calculated scores such as the FIB-4 index or NAFLD Fibrosis Score (which incorporate age, liver enzymes, and platelet count) as a first step; age-adjusted cut-offs should be applied, and those with intermediate or high-risk scores require further assessment. Patients with low-risk results may be monitored in primary care, whilst those with results suggesting advanced fibrosis require specialist hepatology assessment and consideration for transient elastography (FibroScan) to measure liver stiffness.

Baseline investigations typically include:

• Liver function tests (ALT, AST, GGT, ALP, bilirubin, albumin)

• Full blood count and platelet count

• Fasting glucose and HbA1c

• Lipid profile

• Tests to exclude other causes of liver disease: hepatitis B surface antigen (HBsAg), hepatitis C antibody (anti-HCV), ferritin and transferrin saturation (iron overload), autoimmune liver antibodies, and coeliac serology

• Liver ultrasound to assess fat accumulation and exclude other abnormalities

• Review of alcohol intake and all medications (including over-the-counter and herbal products)

Liver enzyme levels should be monitored every 6–12 months in patients with NAFLD. Interpretation should use local laboratory reference ranges rather than fixed cut-offs, and trends over time are more informative than single values. Importantly, normal liver enzyme levels do not exclude significant liver disease. A falling platelet count or rising bilirubin may indicate advancing fibrosis or cirrhosis. Repeat ELF testing is typically recommended approximately every three years to reassess fibrosis risk.

Long-term management focuses on maintaining weight loss, optimising metabolic control, and surveillance for complications. Patients with cirrhosis require ultrasound scanning every six months for liver cancer (hepatocellular carcinoma) surveillance, with or without alpha-fetoprotein blood testing, according to local protocols. Upper gastrointestinal endoscopy is performed to assess for oesophageal varices (enlarged veins) as per hepatology guidance. Annual cardiovascular risk assessment is crucial, as cardiovascular disease remains the leading cause of death in people with NAFLD.

Vaccinations should be offered as indicated, including hepatitis A and B for those at risk or with advanced liver disease, and annual influenza and pneumococcal vaccines according to the UK immunisation schedule (Green Book).

Patient education should emphasise that NAFLD is a chronic condition requiring lifelong management. Individuals should be advised to limit alcohol consumption—both men and women should not regularly drink more than 14 units per week, spread over three or more days with several drink-free days each week. Patients should avoid potentially liver-damaging substances, including certain medications and herbal supplements, and should always inform healthcare professionals of their liver condition. Patients should contact their GP if they develop new symptoms such as yellowing of the skin or eyes (jaundice), abdominal swelling, confusion, unexplained bruising or bleeding, or vomiting blood, as these may indicate liver deterioration requiring urgent specialist referral.

Frequently Asked Questions