My father in law did not drink. That is the first thing everyone said when his GP phoned to say his liver blood tests were "a bit off" and he ought to come in. He was 58, a retired postman, a man who walked twelve miles a day for thirty years and then, in the space of five years of retirement, stopped walking almost entirely. He put on two and a half stone. He drank a lot of cola. He was, by his own cheerful description, "a bit round". Nobody in the family had ever connected that to his liver, because in our heads liver disease was something that happened to heavy drinkers, and Ray was not one.
He had fatty liver disease with early scarring. His FibroScan reading was 9.8 kPa, which his hepatologist described as "a warning, not a sentence". This is the article I wish someone had handed us that afternoon, before we went home and typed "how to prevent liver disease" into a phone and got a wall of supplement adverts. It covers what liver disease actually is, who gets it and why, and the handful of habits that the evidence says genuinely protect the liver, with the studies linked so you can check them yourself.
This article is for information only and is not a substitute for advice from your own doctor. If you have abnormal liver tests, jaundice, dark urine, pale stools, swelling in your legs or abdomen, or confusion, please seek medical care promptly.
What liver disease actually means
Your liver is roughly the size of a rugby ball, sits under your right ribs, and does more than 500 jobs: it filters blood, stores energy, makes bile for digesting fat, builds clotting proteins, and breaks down alcohol, medicines and hormones. It is also the only internal organ that can regrow. You can lose two thirds of it and, given the right conditions, it will rebuild itself in months.
"Liver disease" is not one illness. It is an umbrella for anything that injures liver cells over months and years. The damage follows a common path regardless of the cause: fat or inflammation first, then scar tissue (fibrosis), then, in a minority, so much scar that the liver's structure is replaced (cirrhosis). The cause decides how fast that happens. The stage decides how reversible it is.
The important shift in the last decade is which cause leads. In the 1990s, alcohol and viral hepatitis dominated. Today, the single largest cause of chronic liver disease worldwide is fat in the liver from excess weight and insulin resistance, now called metabolic dysfunction associated steatotic liver disease, or MASLD (previously NAFLD). A 2023 review in the Journal of Hepatology estimated that about 38 percent of adults worldwide have some fat in their liver, and that liver disease causes about two million deaths a year, roughly one in every 25 deaths on the planet.
Who is at risk: the honest list
Ray's story is the typical one now, and it is worth spelling out why, because the risk factors overlap heavily with those for type 2 diabetes and heart disease.
| Risk factor | Why it damages the liver | Strength of evidence |
|---|---|---|
| Excess weight, especially around the waist | Fat spills from full fat cells into the liver; visceral fat drives insulin resistance | Very strong. Around 70 to 80 percent of people with obesity have fatty liver (Younossi 2016) |
| Type 2 diabetes or prediabetes | Insulin resistance pushes the liver to make and store fat | Very strong. About 55 percent of people with type 2 diabetes have MASLD and 1 in 6 already has significant fibrosis (Younossi 2019) |
| Alcohol above 14 units a week | Direct toxicity from acetaldehyde, plus fat accumulation | Very strong, dose dependent, worse for women |
| Sugary drinks and fruit juice | Fructose is metabolised almost entirely in the liver and converted to fat | Strong, consistent across cohorts |
| Hepatitis B or C infection | Ongoing viral inflammation | Very strong. Both are now testable and treatable |
| Family history | Gene variants like PNPLA3 double or triple the risk; common in people of South Asian and Hispanic heritage | Strong |
| Physical inactivity | Muscles that do not move do not clear glucose; liver fat rises independently of weight | Strong |
| Certain medicines and supplements | Methotrexate, amiodarone, long term high dose paracetamol, some bodybuilding and herbal products | Moderate to strong depending on the drug |
One point people from South Asian, East Asian and Hispanic backgrounds should know: fatty liver appears at lower body weights. This is why the NHS uses a lower "overweight" threshold for these groups, and why our BMI calculator has a toggle for the adjusted Asian and Black thresholds. A BMI of 24 can carry a "Western" BMI of 27's worth of liver risk. If that is you, take waist size seriously even when the scales look fine.
Early warning signs (and why there usually are none)
The uncomfortable truth is that the liver does not hurt. It has very few pain nerves, and it keeps working at near full capacity until a large part of it is scarred. Ray felt completely well. Most people with fatty liver, and many with early cirrhosis, feel completely well.
Signs that do appear, usually late, include persistent tiredness, itchy skin, easy bruising, spider shaped blood vessels on the chest, red palms, yellowing of the eyes or skin, dark urine, pale stools, and swelling in the ankles or abdomen. Any of these needs a doctor promptly. But please do not wait for them. The way to catch liver disease early is a blood test and a simple calculation, not a symptom.
If you have type 2 diabetes, obesity, or drink above the guideline, ask your GP for liver function tests and a FIB-4 score. The NICE NG49 guideline and the 2024 EASL guideline both recommend this. It costs almost nothing and it is how Ray was caught at 9.8 kPa rather than at 25.
How to prevent liver disease: the seven habits with evidence
1. Lose weight if you carry extra, and aim for 7 to 10 percent
This is the single most powerful intervention and the numbers are unusually precise. In a 2015 study in Gastroenterology, Vilar-Gomez and colleagues followed 293 people with biopsy proven steatohepatitis through a year of lifestyle change and then re-biopsied them. Losing 5 to 7 percent of body weight resolved the inflammation in a quarter of them. Losing 7 to 10 percent resolved it in two thirds. Losing 10 percent or more resolved it in 90 percent and reversed fibrosis in 81 percent.
For Ray, at 98 kg, ten percent was just under 10 kg. It took him eight months. Check your own numbers on the BMI calculator, which shows the healthy weight range for your height and what a 5 and 10 percent loss looks like in kilograms. And if you want the fuller picture on sustainable weight loss, our obesity diet and exercise plan goes deep on the practicalities.
2. Keep alcohol under 14 units a week, with alcohol free days
The relationship between alcohol and cirrhosis is a curve, not a cliff. A 2019 meta analysis in the American Journal of Gastroenterology found risk rising gently up to about 14 UK units a week (roughly six pints of ordinary strength beer or a bottle and a half of wine), then steeply beyond it. Daily drinking carried more risk than the same weekly amount spread over fewer days, and women reached each risk level at lower intakes.
The combination that worries hepatologists most is moderate drinking on top of a fatty liver. A large Swedish cohort in Hepatology 2023 found that people with metabolic risk factors who also drank moderately had far higher rates of advanced liver disease than either factor alone. If you are overweight or diabetic, your safe alcohol ceiling is lower than the general one.
3. Cut sugary drinks and fruit juice to almost nothing
Fructose is unusual among sugars: your muscles cannot use it directly, so almost all of it is processed by the liver, which turns the excess into fat on the spot. In the Framingham cohort (Ma 2015), people drinking a sugary drink a day had about 55 percent higher odds of fatty liver than those drinking none. Fruit juice behaves the same way; whole fruit, with its fibre and slow release, does not.
This was the single change Ray found easiest and that his hepatologist thought mattered most. He switched to sparkling water with a slice of lime and, within three months, his ALT (a liver enzyme) had dropped by a third before he had lost much weight at all.
4. Move most days, and lift something twice a week
Exercise lowers liver fat even when you do not lose weight, which surprises people. A meta analysis in the Journal of Hepatology 2012 found that aerobic exercise reduced liver fat by about 20 to 30 percent on MRI with minimal weight change. The American College of Sports Medicine's 2023 position statement (Stine 2023) recommends at least 150 minutes a week of moderate activity and notes that resistance training works too, which matters for people who cannot manage brisk walking.
Ray went back to walking. Not twelve miles, but forty minutes each morning along the canal with his daughter, and two sessions a week with a pair of dumbbells in the garage. Our liver disease diet and exercise plan sets out a week that works if you are starting from nothing.
5. Drink coffee
This is one of the most consistent findings in liver research and it still makes people laugh when they hear it. A meta analysis of nine studies covering 432,000 people (Kennedy 2016) found that each additional cup of coffee a day was linked to about a 20 percent lower risk of cirrhosis, with four cups associated with a 65 percent reduction. The effect held for filtered and instant coffee, and appears at least partly independent of caffeine.
6. Get tested and vaccinated for viral hepatitis
Hepatitis B and C between them cause about a quarter of all cirrhosis and most liver cancer worldwide. Both are preventable or curable now. Hepatitis B has a safe vaccine given to all babies in the UK since 2017 and available to any adult at risk. Hepatitis C has no vaccine but is cured in over 95 percent of people with 8 to 12 weeks of tablets (AASLD/IDSA guidance). The UK offers free home testing kits. If you were born before 1965, ever injected drugs even once, had a blood transfusion before 1992, or a tattoo in a non regulated setting, get tested. Most people who have hepatitis C do not know.
7. Be careful with paracetamol, supplements and "liver detox" products
Paracetamol is safe at the labelled dose and dangerous above it. It is the leading cause of acute liver failure in the UK and US (Larson 2005). Never exceed 4 g a day, less if you are small, drink regularly, or are not eating. Check combination cold remedies, which often contain it.
Herbal and bodybuilding supplements now cause about 20 percent of drug induced liver injury in the US, up from 7 percent in 2004 (Navarro 2014). Green tea extract in high doses, kava, comfrey, anabolic steroids and many "fat burner" blends are repeat offenders. There is no such thing as a liver detox product with evidence behind it. Your liver is the detox. Feed it well and leave it alone.
Your liver protection checklist
- Know your BMI and waist size. Use the BMI calculator with the ethnic adjustment if it applies.
- If you have diabetes, obesity or drink above 14 units, ask for liver blood tests and a FIB-4 score.
- Aim to lose 7 to 10 percent of your weight if you carry extra. Slowly is fine; it took Ray eight months.
- Stay under 14 units of alcohol a week with at least two dry days. Less if you have a fatty liver.
- Replace sugary drinks and juice with water, tea or coffee.
- Walk 30 to 40 minutes most days and do some resistance work twice a week.
- Drink two to three cups of coffee a day if you enjoy it.
- Get tested for hepatitis C once. Get vaccinated for hepatitis B if at risk.
- Respect paracetamol doses and skip herbal liver products.
What happened to Ray
Fourteen months after that phone call, Ray had his second FibroScan. His stiffness reading had fallen from 9.8 to 6.1 kPa, back into the normal range. His ALT was 24. He had lost 11 kg, walked every morning, drank a lot of coffee and no cola, and had a glass of wine on Saturdays. His hepatologist discharged him back to his GP with a handshake and the phrase "you did that, not me".
I include the numbers because when we sat in that waiting room, nobody told us that reversal was not just possible but likely. The liver forgives more than almost any other organ. It asks for a modest weight loss, less sugar, less alcohol, more walking, and the odd cup of coffee. That is a manageable list. If you are where Ray was, start with the drinks.
Read next
- Can a damaged liver heal? Fatty liver, cirrhosis and hepatitis treatment explained
- Liver disease diet and exercise plan: foods to eat and avoid
- BMI calculator with Asian and Black adjusted thresholds
- How to prevent obesity: causes and what works
- How to prevent gallstones: 7 habits backed by research
Frequently asked questions
Can you have liver disease if you do not drink?
Yes. Fatty liver disease from excess weight and insulin resistance is now the most common liver disease in the world and affects about one in three adults, most of whom drink little or nothing.
What are the first signs of liver damage?
Usually none. When signs appear they include tiredness, itching, easy bruising, yellow eyes, dark urine, pale stools and swelling. A routine blood test with a FIB-4 calculation is the reliable way to find early disease.
Is fatty liver reversible?
Yes, in the great majority of cases. Losing 7 to 10 percent of body weight resolves the inflammation in most people and even early scarring can regress over one to two years.
Is coffee really good for the liver?
Large observational studies consistently link two to four cups a day with lower rates of cirrhosis and liver cancer. It is not a treatment on its own, but there is no reason to avoid it and reasonable grounds to enjoy it.
How much alcohol is safe for the liver?
Risk rises steeply above 14 UK units a week. If you already have a fatty liver, diabetes or obesity, less is safer, and many hepatologists advise near zero until the liver has recovered.
