Non-alcoholic fatty liver disease affects an estimated 1 in 3 UK adults. It causes no symptoms until advanced. Standard NHS liver function tests miss the majority of early cases because the reference ranges are too wide. A comprehensive liver blood test checks the full enzyme panel alongside the metabolic markers that drive fatty liver, and provides the data to calculate a FIB-4 fibrosis score. The TrueVitals Ultimate panel covers the complete liver picture within 114 biomarkers for £349.
A Lancet Gastroenterology and Hepatology meta-analysis estimated the global prevalence of NAFLD at 32% of the adult population and rising. In the UK, the British Liver Trust describes it as a "ticking time bomb" driven by obesity, type 2 diabetes, and metabolic syndrome. NAFLD is now the most common liver condition in the Western world and the fastest-growing indication for liver transplantation in the UK.
The disease progresses through four stages, each detectable by different means, each with a different prognosis:
Fat accumulation in more than 5% of liver cells. No inflammation. No symptoms. ALT may be mildly elevated or completely normal. Fully reversible with weight loss (5-10% of body weight), dietary changes, and exercise. This is where most people with fatty liver sit. The liver is coping but stressed.
Steatosis plus inflammation and liver cell damage. Develops in approximately 20 to 30% of people with simple steatosis. Still no obvious symptoms in most people. ALT and AST are typically elevated but may still fall within "normal" NHS ranges. Still reversible with aggressive lifestyle intervention, but the window is narrowing.
Scar tissue forms in the liver. The FIB-4 score (calculated from age, AST, ALT, and platelet count) is the first-line non-invasive assessment recommended by NICE NG49. Fibrosis is harder to reverse but progression can be halted. Symptoms may begin to emerge: fatigue, right upper abdominal discomfort.
Extensive scarring. Liver function is compromised. Risk of liver failure and hepatocellular carcinoma. Largely irreversible. This is where symptoms become obvious, but by this stage the damage is done. NAFLD-related cirrhosis is the fastest-growing indication for liver transplantation in the UK.
The entire progression from stage 1 to stage 3 can happen with no symptoms. The liver does not hurt. It does not send warning signals. Blood testing is the primary detection tool, and early detection is the difference between a lifestyle adjustment and a chronic disease.
The NHS reference range for ALT is 0 to 41 U/L. Any value below 41 is reported as "normal." But published research suggests tighter optimal thresholds: below 30 U/L for men and below 19 U/L for women. A man with an ALT of 35 is within the NHS "normal" range but above the evidence-based optimal threshold. He may already have early fatty liver disease that the standard test reports as healthy.
The same applies to GGT. The NHS range extends to 60 U/L, but GGT above 30 U/L in the context of metabolic risk factors (abdominal obesity, insulin resistance, elevated triglycerides) is already clinically meaningful. GGT is not just an alcohol marker. It reflects oxidative stress in the liver and is independently associated with both liver disease progression and cardiovascular mortality.
This is why context matters more than any single number. ALT of 35 in a lean, active 25-year-old is different from ALT of 35 in a 50-year-old with abdominal obesity and elevated fasting insulin. The number is the same. The clinical significance is completely different. A comprehensive panel that tests liver enzymes alongside metabolic markers provides the context that a standalone liver function test cannot.
ALT (liver-specific damage marker), AST (liver + muscle), GGT (oxidative stress, bile duct, alcohol), ALP (bile duct, bone), bilirubin (bilirubin processing), albumin (synthetic function). The AST:ALT ratio is informative: below 1 suggests fatty liver, above 1 suggests advanced fibrosis.
Calculated from age, AST, ALT, and platelet count. NICE NG49 recommends it as first-line non-invasive fibrosis assessment. Under 65: below 1.3 = low risk, above 2.67 = high risk. Over 65: below 2.0 = low risk. No additional blood tests needed — it uses data already in the panel.
Fasting insulin, HOMA-IR, HbA1c, fasting glucose. Insulin resistance is the primary driver of NAFLD. Testing liver enzymes without metabolic context is like checking the smoke detector without looking for the fire. Insulin resistance guide.
Elevated triglycerides with low HDL is a hallmark of metabolic syndrome and NAFLD. The triglyceride:HDL ratio is a surrogate marker for insulin resistance. Full lipids (including ApoB) connect liver health to cardiovascular risk. Cardiovascular guide.
hs-CRP measures systemic inflammation. NASH is characterised by liver inflammation. Elevated CRP alongside elevated liver enzymes and metabolic dysfunction suggests progression beyond simple steatosis.
Platelet count is required for FIB-4 calculation. Low platelets can indicate advanced fibrosis or cirrhosis (the liver's role in thrombopoietin production is impaired). FBC provides baseline haematological context.
The TrueVitals Ultimate panel includes full liver enzymes (ALT, AST, GGT, ALP, bilirubin, albumin), the data for FIB-4 calculation, fasting insulin, HOMA-IR, full lipids, hs-CRP, and FBC — alongside 100+ additional markers. 114 biomarkers. Results in 48 hours. £349.
You carry weight around your abdomen. Visceral fat is the strongest driver of NAFLD. Central obesity correlates with liver fat accumulation more than total body weight.
You drink regularly. Even moderate alcohol consumption compounds fatty liver risk. Combine metabolic NAFLD with regular alcohol intake and the liver faces a double burden. Testing establishes whether damage is accumulating.
You have type 2 diabetes or insulin resistance. NAFLD prevalence reaches 55% in people with type 2 diabetes. Insulin resistance is the metabolic engine that drives fat into liver cells. Prediabetes guide.
You take supplements or medications that stress the liver. High-dose paracetamol, certain herbal supplements, anabolic steroids, and some prescription medications can elevate liver enzymes. Monitoring confirms whether your liver is coping.
You train hard and had elevated AST/ALT on a previous test. Muscle damage from training elevates AST and ALT. GGT and bilirubin distinguish exercise-induced elevation from liver pathology. Gym blood test guide.
You're over 40 and have never had a liver check. NAFLD prevalence increases with age. By 40, establishing a liver baseline is part of responsible health screening. Health check at 40 (men). Health check at 40 (women).
Simple steatosis and early NASH are reversible with lifestyle intervention. The evidence is clear: 5 to 10% body weight loss reduces liver fat significantly. Resistance training has been shown to reduce liver fat within 3 months even without weight loss. Reducing refined carbohydrates and fructose intake directly decreases hepatic fat synthesis. Reducing alcohol (or eliminating it) removes the second hit on an already stressed organ.
The critical point is detection timing. A man whose ALT is 38, fasting insulin is elevated, and triglycerides are high almost certainly has early fatty liver. If he's told his liver test is "normal" (because 38 is below 41), he changes nothing. If he's told his ALT is above the evidence-based optimal threshold and his metabolic markers show insulin resistance driving fat into his liver, he has specific, actionable information and a reason to act.
The comprehensive report identifies this pattern. It connects elevated liver enzymes to insulin resistance, lipid profiles, and inflammatory markers. It provides specific dietary, exercise, and supplement recommendations targeting liver fat reduction. A standalone liver function test saying "normal" does none of this.
Most liver blood tests give you six enzyme values with traffic-light dots. The TrueVitals report analyses liver enzymes alongside fasting insulin, HOMA-IR, triglycerides, HDL, hs-CRP, and body system markers to identify whether liver stress is metabolic (insulin resistance), inflammatory (NASH progression), alcohol-related, or exercise-induced. It calculates your FIB-4 score automatically. It explains what each pattern means and provides specific, evidence-based recommendations for liver fat reduction. A medical professional reviews every report.
114 biomarkers including full liver enzymes, FIB-4 data, fasting insulin, HOMA-IR, full lipids, and inflammatory markers. The complete liver picture plus the metabolic context that drives it. Results in 48 hours.
.png)