Protein and Liver Disease: Cirrhosis, Fatty Liver and Hepatic Encephalopathy
What liver guidelines and trials say about protein in cirrhosis, fatty liver and hepatic encephalopathy, why protein restriction is no longer advised, and why supplements need a clinician.
Content last updated . This page has not been medically reviewed.
Urgent first
If you have been diagnosed with cirrhosis and you are vomiting blood, your stools are very dark or black, or you suddenly become confused or have slurred speech, the UK National Health Service (NHS) says to call 999 or go to A&E and not to drive yourself. [1] In the US, call 911. Confusion, difficulty thinking, memory loss and personality or sleep changes are also listed by NIDDK as symptoms of cirrhosis. [2]Start here
This page is information only. Protein and amino acid choices in liver disease depend on the stage and cause of the liver disease, and are made with a liver specialist and dietitian. NIDDK says to talk with your doctor before taking dietary supplements, including herbal supplements, if you have cirrhosis. [3] See Liver Safety and Supplements.How to read the evidence on this page
We label findings: "guideline recommendation" (an expert group's advice), "mixed" (studies disagree), "limited" (small or short studies) and "Proper evidence not found". A short-term blood ammonia change is a biomarker, not a clinical outcome.Cirrhosis: why protein matters
NIDDK says research suggests 50% to 90% of people with cirrhosis have malnutrition, and advises avoiding going without food for too long. [3] The European Association for the Study of the Liver (EASL) 2019 guideline states that optimal daily protein intake in people with cirrhosis should not be lower than 1.2 to 1.5 g/kg of body weight per day. [4] That is grams of protein per kilogram of body weight, not grams of food. It also recommends including a late evening nutritional supplement and breakfast for malnourished decompensated patients. [4] Do not copy these numbers: they are for people with diagnosed cirrhosis under a care team. They are higher than the general-population figures described on Protein Foundations.| Source and year | Group | What it says | Unit | Evidence label |
|---|---|---|---|---|
| EASL guideline, 2019 | Adults with liver cirrhosis | Daily protein not lower than 1.2 to 1.5 [4] | g/kg body weight/day | Guideline recommendation |
| EASL guideline, 2019 | Malnourished decompensated cirrhosis | Include late evening supplement and breakfast [4] | meal timing | Guideline recommendation |
| EASL guideline, 2019 | Decompensated cirrhosis | BCAA and leucine-enriched amino acid supplements to reach adequate nitrogen intake [4] | clinician-directed | Guideline recommendation |
EASL says obesity does not rule out malnutrition in cirrhosis. [4] For overweight people with compensated cirrhosis who are losing weight, it says good quality data are lacking but particular attention must be paid to the protein needed to maintain muscle mass. [4]
Hepatic encephalopathy and the old low-protein advice
Hepatic encephalopathy (HE) is a brain complication of liver disease. For decades protein was restricted in people with HE. EASL now states that protein restriction is considered detrimental, except perhaps for very short periods in severe overt HE with gastrointestinal bleeding. [4] It also states that normal to high protein intake does not precipitate HE. [4] A 2011 review argued low-protein diets should be abandoned after a 2004 randomized study found a normal-protein diet safe. [5] A 2021 review calls the evidence for vegetarian protein reducing HE symptoms limited and says larger trials are needed. [6]EASL notes some people with HE may tolerate meat protein less well than vegetable and dairy protein and says to ask your doctor or dietitian before changing protein intake; it advises not to reduce total protein. [4] One randomized study of 20 g of protein from a meat, vegetarian or vegan burger found serum ammonia rose in the meat group but not the others, a short-term biomarker. [7]
Branched-chain amino acid (BCAA) products appear in the EASL guideline as a clinician-directed option for decompensated cirrhosis. [4] The sources we read do not show that sports BCAA powders are equivalent or safe for liver disease; see BCAAs: Leucine, Isoleucine and Valine.
Fatty liver (NAFLD/MASLD)
NIDDK says people with NAFLD, also called MASLD, may be advised to lose weight gradually if they have overweight or obesity, change fats, and limit simple sugars; it advises minimizing alcohol. [8] Its page does not set a protein target. A 2023 meta-analysis of 60 studies found the share of calories from protein did not significantly differ between people with NAFLD and controls. [9] Proper evidence not found for a protein amount or protein/amino acid supplement that treats fatty liver: we searched PubMed for protein intake and NAFLD, and read the NIDDK page and the NHS page, and found no recommendation we could use.Related
High-Protein Diets: Benefits and Risks · Protein Intake LevelsFrequently asked questions
Should people with cirrhosis eat less protein?
EASL's 2019 guideline says protein intake should not be lower than 1.2 to 1.5 g/kg/day in people with cirrhosis, and its patient text says not to reduce total protein. [4] Your care team sets your plan.
Does protein cause hepatic encephalopathy?
EASL states that normal to high protein intake does not precipitate HE, and protein restriction is now considered detrimental apart from very short periods in severe cases. [4]
Are BCAA supplements good for liver disease?
EASL describes BCAA and leucine-enriched supplements for decompensated cirrhosis to reach adequate nitrogen intake. [4] Over-the-counter sports products were not assessed in the sources we read.
Is there a protein plan for fatty liver?
Proper evidence not found for a protein target in fatty liver. NIDDK advises weight loss if overweight, changes to fats and sugars, and limiting alcohol. [8]
Why does a late evening snack come up?
NIDDK says people with cirrhosis should avoid long gaps without food. [3] EASL recommends a late evening supplement and breakfast for malnourished people with decompensated cirrhosis. [4]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety
- Medicines and herbs: liver disease changes how medicines are handled; see Medication Interactions and ask a pharmacist.
- Alcohol: NIDDK says people with cirrhosis should completely stop drinking alcohol. [3]
- Food safety: avoid raw or undercooked shellfish, fish, meat and unpasteurized milk; infections can be severe in cirrhosis. [3]
- Powders and quality: see Protein Powder Safety and Quality Testing and Certifications.
- Pregnancy, children and surgery: the sources we read give no protein guidance for these groups with liver disease; see Pregnancy and Breastfeeding and Supplements Before Surgery. EASL has a section on malnutrition in patients undergoing liver surgery and liver transplantation; ask your surgical team. [4]
- Kidney problems often occur alongside: see Protein and Kidney Disease.
References
- NHS (UK). Cirrhosis. Page last reviewed 10 February 2025. Read 2026-10-23.
- NIDDK (US National Institutes of Health). Symptoms & Causes of Cirrhosis. Last reviewed June 2023. Read 2026-10-23.
- NIDDK (US National Institutes of Health). Eating, Diet, & Nutrition for Cirrhosis. Last reviewed June 2023. Read 2026-10-23.
- European Association for the Study of the Liver. EASL Clinical Practice Guidelines on nutrition in chronic liver disease. Journal of Hepatology 2019. Read 2026-10-23.
- Low-protein diets for hepatic encephalopathy debunked: let them eat steak. Nutrition in Clinical Practice 2011 (PubMed abstract). Read 2026-10-23.
- A Comprehensive Review Evaluating the Impact of Protein Source (Vegetarian vs. Meat Based) in Hepatic Encephalopathy. Nutrients 2021 (PubMed abstract). Read 2026-10-23.
- Substitution of One Meat-Based Meal With Vegetarian and Vegan Alternatives Generates Lower Ammonia and Alters Metabolites in Cirrhosis: A Randomized Clinical Trial. Clinical and Translational Gastroenterology 2024 (PubMed abstract). Read 2026-10-23.
- NIDDK (US National Institutes of Health). Eating, Diet, & Nutrition for NAFLD & NASH. Last reviewed April 2021. Read 2026-10-23.
- Systematic Review and Meta-analysis: The Role of Diet in the Development of Nonalcoholic Fatty Liver Disease. Clinical Gastroenterology and Hepatology 2023 (PubMed abstract). Read 2026-10-23.