Fatty liver disease, now called MASLD (metabolic dysfunction-associated steatotic liver disease), is the most common liver condition in the world, affecting roughly a third of adults. Most people have no symptoms and normal-looking blood tests. The danger is the minority who progress to inflammation (MASH), scarring (fibrosis) and eventually cirrhosis. And the leading cause of death in people with fatty liver is actually heart disease.
The good news: it is often reversible. Losing about 5% of body weight reduces liver fat; 7–10% can resolve inflammation; 10% or more can reverse scarring. In December 2025, Health Canada gave Wegovy conditional approval as the first drug for MASH with moderate to advanced fibrosis. And in trials, retatrutide brought liver fat back to normal in 86–93% of participants. Here is the complete guide.
NAFLD, MASLD, MASH: the new names
In 2023, international liver societies renamed fatty liver disease to emphasize its metabolic cause and drop the stigmatizing term “fatty” from the medical name (Rinella et al., 2023):
| Old name | New name | Meaning |
|---|---|---|
| NAFLD (non-alcoholic fatty liver disease) | MASLD | Excess liver fat plus at least one metabolic risk factor |
| NASH (non-alcoholic steatohepatitis) | MASH | Liver fat plus inflammation and cell injury |
| — | MetALD | Metabolic fatty liver plus moderate alcohol intake |
You will still see the old terms on many websites and in older reports. They describe essentially the same conditions.
The stages, from fat to cirrhosis
| Stage | What’s happening | Reversible? |
|---|---|---|
| Steatosis (simple fatty liver) | Fat builds up in more than 5% of liver cells | Yes |
| MASH | Fat plus inflammation and injury to liver cells | Yes |
| Fibrosis (F1–F3) | Scar tissue forms | Often, with enough weight loss |
| Cirrhosis (F4) | Extensive scarring, distorted liver structure | Partly, at best; risk of liver failure and cancer |
Most people with MASLD never progress beyond simple steatosis. Fibrosis stage is the single most important predictor of long-term outcome, which is why assessing it is the focus of diagnosis.
Who gets it
- People with obesity, especially abdominal fat
- Type 2 diabetes or prediabetes: a majority of people with type 2 diabetes have MASLD
- High triglycerides, low HDL, high blood pressure
- Polycystic ovary syndrome (see PCOS treatment)
- Sleep apnea
- Some ethnic groups, notably people of Hispanic and South Asian descent, at lower body weights
- Children and teens with obesity, increasingly
It also occurs in people of normal weight (“lean MASLD”), often with insulin resistance or genetic factors.
Symptoms (usually none)
Most people feel nothing. Some notice fatigue or a dull ache in the upper right abdomen. Liver enzymes (ALT, AST) may be mildly raised, but normal liver enzymes do not rule out fatty liver or even significant fibrosis. Often it’s found incidentally on an ultrasound done for something else.
Signs of advanced disease, such as yellowing skin, abdominal swelling, easy bruising or confusion, appear only with cirrhosis and need urgent medical attention.
How it’s diagnosed: FIB-4 and FibroScan
Liver biopsy used to be the only way to stage fibrosis. Today, guidelines recommend a non-invasive, stepwise approach (Rinella et al., 2023):
- Find the fat: often on ultrasound.
- Calculate FIB-4: a simple score from age, AST, ALT and platelet count, using routine blood tests. A low score makes advanced fibrosis unlikely.
- If FIB-4 is intermediate or high: vibration-controlled transient elastography (FibroScan) measures liver stiffness, which reflects scarring, plus a fat score.
- Specialist referral if stiffness suggests significant fibrosis.
- Biopsy only when results are unclear or another liver disease is suspected.
“What is my FIB-4 score?” It uses blood tests you may already have had, and it tells you whether you need further testing.
The treatment scorecard
| Treatment | Evidence | Effect |
|---|---|---|
| Weight loss of 7–10%+ | Very strong | Resolves MASH, can reverse fibrosis |
| Exercise | Strong | Reduces liver fat, even without weight loss |
| Mediterranean-style diet | Strong | Reduces liver fat and cardiovascular risk |
| Semaglutide (Wegovy) | Strong (phase 3) | Approved for MASH F2–F3 in Canada (conditional) |
| Resmetirom | Strong (phase 3) | US-approved for MASH F2–F3 |
| Vitamin E | Moderate | Improves MASH in non-diabetic adults |
| Pioglitazone | Moderate | Improves MASH, especially with diabetes |
| Bariatric surgery | Strong | Large improvements in MASH and fibrosis |
| Retatrutide / tirzepatide / survodutide | Phase 2 liver data | Large reductions in liver fat and MASH |
Weight loss: the numbers that matter
A landmark study of people with biopsy-proven NASH who made lifestyle changes for a year found clear thresholds (Vilar-Gomez et al., 2015):
| Weight lost | What happened |
|---|---|
| About 5% | Liver fat reduced |
| 7% or more | Inflammation (NASH) resolved in most |
| 10% or more | NASH resolved in about 90%, and fibrosis regressed in many |
The problem: only about 1 in 10 participants reached 10% with lifestyle alone. That is why medications that produce large weight loss have become so important for this disease. Losing weight gradually is preferable; very rapid weight loss can occasionally worsen liver inflammation.
What to eat
- Mediterranean-style eating: vegetables, legumes, whole grains, fish, olive oil, nuts. It reduces liver fat even with modest weight loss.
- Cut sugary drinks: fructose in sugar-sweetened beverages and juices is converted to fat in the liver very efficiently.
- Limit refined carbohydrates and ultra-processed foods.
- Reduce saturated fat (processed meats, butter, pastries).
- Adequate protein helps preserve muscle during weight loss; muscle is important for blood sugar control.
- Calorie reduction matters most: the type of diet that you can sustain is the right one.
Exercise works even without weight loss
Both aerobic exercise and resistance training reduce liver fat in trials, even when body weight barely changes. Exercise improves insulin sensitivity, which reduces the flow of fat to the liver. A practical target: about 150 minutes a week of moderate activity plus two strength sessions. For people who struggle with weight loss, this is an important message: the liver benefits from exercise on its own.
Alcohol, coffee and supplements
- Alcohol: there’s no proven safe amount once fibrosis is present. Many hepatologists recommend avoiding alcohol entirely with significant fibrosis, and minimizing it otherwise.
- Coffee: regular coffee drinking is consistently associated with less fibrosis in observational studies. It’s not a treatment, but there’s no reason to stop.
- Milk thistle (silymarin): popular, with small and inconsistent effects.
- Omega-3: lowers triglycerides; doesn’t clearly improve MASH.
- “Liver detox” products: no evidence, and some herbal supplements, such as concentrated green tea extract and turmeric products, have been linked to liver injury.
Medications: Wegovy, resmetirom, vitamin E and more
Semaglutide (Wegovy): approved in Canada for MASH
In the ESSENCE phase 3 trial in people with MASH and moderate to advanced fibrosis (F2–F3), semaglutide 2.4 mg weekly met both primary goals at 72 weeks: more resolution of steatohepatitis without worsening fibrosis, and more improvement in fibrosis without worsening steatohepatitis, compared with placebo (Sanyal et al., 2025). On December 15, 2025, Health Canada granted Wegovy conditional marketing authorization as the first treatment for adults with non-cirrhotic MASH with moderate to advanced fibrosis. Conditional means confirmatory long-term outcome data are still expected.
Resmetirom (Rezdiffra)
Resmetirom is a liver-directed thyroid hormone receptor-beta agonist that increases fat burning in liver cells. In the MAESTRO-NASH trial it improved both MASH and fibrosis versus placebo (Harrison et al., 2024), and the US FDA approved it in March 2024 for MASH with F2–F3 fibrosis. When Wegovy was approved in Canada in December 2025, it was described as the first and only approved MASH treatment here, so check current status for resmetirom in Canada.
Vitamin E
In the PIVENS trial, vitamin E improved NASH compared with placebo in adults without diabetes (Sanyal et al., 2010). Guidelines consider it an option for selected non-diabetic patients with biopsy-proven MASH, weighing possible long-term risks. It should be used under medical supervision, not as self-treatment.
Pioglitazone
A diabetes drug that improves insulin sensitivity and has shown improvement in MASH, including in people with prediabetes and type 2 diabetes. Weight gain and fluid retention are drawbacks.
Diabetes drugs with liver benefits
For people with type 2 diabetes and MASLD, GLP-1-based drugs are often preferred because they treat blood sugar, weight and liver fat at once. SGLT2 inhibitors also modestly reduce liver fat.
Tirzepatide, retatrutide and survodutide liver data
Several newer incretin drugs have produced striking liver results in phase 2 trials:
- Retatrutide: in a substudy of people with obesity and MASLD, the 8 mg and 12 mg doses reduced liver fat by more than 80%, and 86% to 93% of participants reached normal liver fat (under 5%) by 24 to 48 weeks (Sanyal et al., 2024). The glucagon component is thought to drive fat clearance directly in the liver.
- Tirzepatide: in the SYNERGY-NASH phase 2 trial, a much higher share of participants achieved MASH resolution without worsening fibrosis than on placebo (Loomba et al., 2024).
- Survodutide (GLP-1 + glucagon): phase 2 results in MASH were strong enough to move it into phase 3 programs focused on liver disease.
None of these is approved for liver disease in Canada. Retatrutide is not approved for any use; see retatrutide phase 3 results and the next weight loss drugs.
Bariatric surgery
For people with severe obesity, bariatric surgery (sleeve gastrectomy or gastric bypass) leads to large, sustained weight loss and resolves MASH in most patients, with regression of fibrosis in many. It is covered by provincial plans in Canada for eligible patients, though wait times vary by province.
Why your heart matters more than your liver
Here’s the counterintuitive fact: for most people with MASLD, the biggest threat is cardiovascular disease, not the liver. Fatty liver travels with insulin resistance, high triglycerides, high blood pressure and diabetes. Managing those risks, with statins when indicated, blood pressure control and not smoking, is a core part of treating fatty liver. Statins are safe in MASLD and are often underused out of misplaced worry about the liver.
Getting care in Canada
| Step | Who | Coverage |
|---|---|---|
| Blood tests, FIB-4, ultrasound | Family doctor or nurse practitioner | Provincial plan |
| FibroScan | Hospital liver clinics, some community clinics | Varies by province; access improving |
| Hepatologist / gastroenterologist | By referral | Provincial plan; waits vary |
| Dietitian | Some primary care teams; private | Varies; often extended benefits |
| Wegovy for MASH | Prescription | Coverage under review by plans |
| Bariatric surgery | Provincial bariatric programs | Provincial plan for eligible patients |
The Canadian Liver Foundation offers patient education resources and support.
Peptide research and the liver
Several research peptides connect to liver biology:
- Retatrutide and tirzepatide: the incretin peptides behind the human liver data above.
- BPC-157: rodent studies from the Zagreb group report protection against several forms of experimental liver injury. There are no human liver studies.
- NAD+: involved in liver energy metabolism; precursor studies are early.
| Research compound | Liver-related research | From |
|---|---|---|
| Retatrutide | Liver fat clearance (phase 2 human data) | $90 |
| Tirzepatide | MASH (phase 2 human data) | $73 |
| BPC-157 | Experimental liver injury (animal) | $22 |
| NAD+ | Cellular energy metabolism | $26 |
These are research compounds for laboratory use, not treatments, with reports in our COA library.
Lean fatty liver
Fatty liver isn’t limited to people with obesity. “Lean MASLD” affects people with a normal BMI, and is more common in people of Asian descent. Drivers include:
- Visceral fat: fat around the organs can be high even when BMI is normal.
- Insulin resistance and prediabetes.
- Genetics: variants in genes such as PNPLA3 increase liver fat and the risk of progression.
- Low muscle mass, which reduces the body’s capacity to handle glucose.
- High intake of sugary drinks and refined carbohydrates.
Management focuses on exercise (especially strength training), dietary quality and modest weight loss of 3% to 5%, which can be enough in lean MASLD. Fibrosis assessment with FIB-4 and elastography is just as important as in people with obesity.
Fatty liver and alcohol (MetALD)
Many people have both metabolic risk factors and regular alcohol intake. The 2023 nomenclature created MetALD for this overlap, recognizing that the two causes add to each other. Practical points:
- Alcohol and metabolic fatty liver together accelerate fibrosis more than either alone.
- Cutting back on alcohol often reduces liver fat and liver enzymes within weeks.
- With significant fibrosis, most hepatologists recommend stopping alcohol entirely.
- Canada’s Guidance on Alcohol and Health (2023) suggests that any reduction in drinking lowers health risks.
Fatty liver in children and teens
MASLD is now the most common chronic liver disease in children in many countries, rising with childhood obesity. It is usually found through elevated ALT on routine blood work in a child with excess weight. Management centres on family-based lifestyle changes, reducing sugary drinks, increasing physical activity and limiting screen time. Some adolescents with obesity are now treated with GLP-1 drugs approved for their age group. Paediatric gastroenterologists manage more complex cases.
A 12-week liver-friendly plan
| Weeks | Focus | Actions |
|---|---|---|
| 1–2 | Drinks | Replace sugary drinks and juice with water, sparkling water, coffee or tea; reduce alcohol |
| 3–4 | Movement | Build to 30 minutes of brisk walking most days; add two short strength sessions |
| 5–6 | Plate | Half vegetables, a quarter protein, a quarter whole grains; olive oil as main fat |
| 7–8 | Snacks and processed foods | Swap ultra-processed snacks for nuts, fruit, yogurt, legumes |
| 9–10 | Portions | Aim for a steady calorie deficit you can sustain; track for a week to see patterns |
| 11–12 | Review | Recheck weight, waist and blood tests with your doctor; set the next target |
A loss of 5% of body weight over 12 weeks is a meaningful first milestone for liver fat.
Fatty liver myths
- “Fatty liver is harmless.” Simple steatosis is low-risk, but MASH and fibrosis can progress to cirrhosis and liver cancer, and fatty liver raises cardiovascular risk.
- “Normal liver tests mean a healthy liver.” Enzymes are often normal even with fibrosis.
- “Only heavy drinkers get liver disease.” Metabolic fatty liver is now the most common liver disease in many countries.
- “Detox cleanses fix the liver.” No evidence; some herbal products cause liver injury.
- “You need to lose a huge amount of weight.” 5% already reduces liver fat; 7–10% has major benefits.
- “Statins harm a fatty liver.” Statins are safe in MASLD and reduce cardiovascular risk, the leading cause of death in these patients.
- “Fruit is bad for the liver.” Whole fruit is fine; the problem is concentrated fructose in sugary drinks and juices.
Questions to ask your doctor
- What is my FIB-4 score, and do I need a FibroScan?
- What stage of fatty liver do I have?
- How much weight loss should I aim for?
- Should I stop drinking alcohol completely?
- Am I a candidate for medication such as semaglutide?
- Should I be on a statin for my heart risk?
- How often should my liver be reassessed?
How fatty liver is monitored over time
| Situation | Typical follow-up |
|---|---|
| Low fibrosis risk (low FIB-4) | Repeat FIB-4 every few years; focus on metabolic health |
| Indeterminate or higher risk | Elastography and specialist follow-up |
| Significant fibrosis (F2–F3) | Regular hepatology follow-up; consider medication |
| Cirrhosis | Liver cancer screening with ultrasound about every six months; screening for varices; specialist care |
Between tests, the most useful things to track yourself are weight, waist circumference, blood pressure, and blood sugar if you have diabetes. Improvements in those usually precede improvements in the liver.
Medications and conditions that cause fatty liver
Not all fatty liver is metabolic. Doctors consider other causes, especially when risk factors don’t fit:
- Medications: long-term corticosteroids, tamoxifen, methotrexate, amiodarone, some antiretrovirals and certain antipsychotics can cause or worsen liver fat.
- Hepatitis C, particularly genotype 3, can cause fatty liver.
- Hypothyroidism and polycystic ovary syndrome.
- Rapid weight loss or malnutrition, paradoxically, including after some bariatric procedures.
- Genetic conditions such as lipodystrophy and rare metabolic disorders.
- Celiac disease, occasionally.
If you take a medication associated with liver fat, don’t stop it on your own; ask your prescriber whether monitoring or alternatives make sense.
FAQ
Tap a question to reveal the answer.
Can fatty liver be reversed?
Yes, often. Losing about 5% of body weight reduces liver fat, 7–10% can resolve inflammation, and 10% or more can reverse scarring in many people.
What is the difference between MASLD and MASH?
MASLD is excess liver fat with metabolic risk factors. MASH is the more serious form, with inflammation and liver cell injury that can lead to scarring.
Is there a medication for fatty liver in Canada?
Yes. In December 2025, Health Canada granted Wegovy (semaglutide) conditional approval for adults with non-cirrhotic MASH and moderate to advanced fibrosis.
Can I have fatty liver with normal blood tests?
Yes. Liver enzymes are often normal, even with significant fibrosis. A FIB-4 score and elastography (FibroScan) give a better picture.
What is the best diet for fatty liver?
A Mediterranean-style diet with fewer sugary drinks and refined carbohydrates, combined with calorie reduction you can sustain.
Does exercise help fatty liver without weight loss?
Yes. Aerobic and resistance exercise reduce liver fat in trials even when body weight barely changes.
Does retatrutide reduce liver fat?
In a phase 2 substudy, 86% to 93% of participants on the higher doses reached normal liver fat by 24 to 48 weeks. Retatrutide is not approved.
Is coffee good for fatty liver?
Regular coffee drinking is associated with less liver fibrosis in observational studies. It isn’t a treatment, but it appears safe and possibly helpful.
Can thin people get fatty liver?
Yes. Lean MASLD affects people with a normal BMI, often driven by visceral fat, insulin resistance, genetics or low muscle mass. Modest weight loss and exercise help.
How often should fatty liver be checked?
It depends on fibrosis risk. Low-risk people may repeat a FIB-4 score every few years; those with significant fibrosis need regular specialist follow-up, and cirrhosis requires liver cancer screening about every six months.
Related reading
- Retatrutide phase 3 results
- Weight loss injections in Canada
- PCOS treatment in Canada
- Muscle loss on GLP-1 drugs
References
- Rinella ME, Lazarus JV, Ratziu V, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Hepatology. 2023. PubMed
- Vilar-Gomez E, Martinez-Perez Y, Calzadilla-Bertot L, et al. Weight loss through lifestyle modification significantly reduces features of nonalcoholic steatohepatitis. Gastroenterology. 2015;149(2):367–378. PubMed
- Sanyal AJ, Chalasani N, Kowdley KV, et al. Pioglitazone, vitamin E, or placebo for nonalcoholic steatohepatitis (PIVENS). N Engl J Med. 2010;362:1675–1685. PubMed
- Harrison SA, Bedossa P, Guy CD, et al. A phase 3, randomized, controlled trial of resmetirom in NASH with liver fibrosis (MAESTRO-NASH). N Engl J Med. 2024. PubMed
- Sanyal AJ, et al. Phase 3 trial of semaglutide in metabolic dysfunction-associated steatohepatitis (ESSENCE). N Engl J Med. 2025. PubMed
- Sanyal AJ, Kaplan LM, Frias JP, et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nat Med. 2024. PubMed
- Loomba R, Hartman ML, Lawitz EJ, et al. Tirzepatide for metabolic dysfunction-associated steatohepatitis with liver fibrosis (SYNERGY-NASH). N Engl J Med. 2024. PubMed
- BioSpace. Wegovy receives conditional marketing authorization from Health Canada for non-cirrhotic MASH. December 2025. BioSpace
This article is general information, not medical advice. Talk to a doctor about liver testing and treatment. TrueLabs research compounds are sold for in vitro and laboratory research use only and are not intended for human or veterinary use.