A Hepatologist’s Guide to Protecting Your Liver Through Food

Jennifer Lai, M.D.

Credit: UCSF

Today marks the final installment of our three-part series on liver health in partnership with the Global Liver Institute (GLI), and we’re closing with conversation featuring Jennifer Lai, M.D., a general and transplant hepatologist and board-certified Physician Nutrition Specialist at UCSF. Lai cares for patients across the full spectrum of liver disease and brings a unique, research-informed perspective to the role that nutrition plays in protecting liver health.

In this interview, she shares practical, science-backed advice on which foods help — or hurt — your liver, what to look for on nutrition labels and why small changes in your diet and activity level can make a lasting impact.

What role does nutrition play in overall liver health?

Jennifer Lai, M.D.: Nutrition is absolutely foundational to overall liver health. The liver — while not the first organ to encounter food (that would be the intestine) — is the major organ responsible for processing food, filtering toxins and converting nutrients into essential proteins the body needs to function.

So the phrase “you are what you eat” is exactly right. If you eat junk, your liver has to process junk. But if you eat well, you’re essentially bathing your liver in healthy nutrients, which helps it stay strong and functional.

Speaking of junk food, what are the biggest dietary risks for liver damage that people may not even be aware of?

JL: The most obvious one is alcohol, which everyone knows can damage the liver in high amounts. But right up there with alcohol is excess fructose, especially high-fructose corn syrup. Like alcohol, your liver can handle some fructose — but it becomes harmful when consumed in large quantities.

And here’s the problem: Ultra-processed foods are packed with hidden sources of added sugar and fructose, so many people are consuming dangerously high amounts without realizing it.

On the flip side, are there specific foods that support liver function or help protect against liver disease?

JL: Yes. We know from research that polyphenols — compounds found in foods like black coffee, green tea, fruits, vegetables and whole grains — have protective effects on the liver. Most studies focus on coffee due to how widely it’s consumed, but fruits and vegetables offer similar benefits. These don’t have to be fresh — frozen or canned versions also contain polyphenols.

What should patients look for when reading food labels to protect their liver?

JL: There are two key things:

• Added sugars: Check the “added sugar” line under the carbohydrate section. Many packaged foods have way more added sugar than people think. A good long-term goal is to get added sugars under 50 grams per day, but if you’re just starting out, aim to reduce your current intake by 10% per month. That gradual approach is more sustainable.
• Fiber: Aim for 25 to 30 grams of fiber per day. Fiber helps feed a healthy gut microbiome, which serves as a first line of defense for the liver by neutralizing toxins before they reach your bloodstream. But again, increase gradually to avoid bloating and cramps.

And honestly, the best foods don’t have labels at all — think apples, greens, legumes, whole grains. If it comes in a box with a long ingredient list, it’s probably not the best for your liver.

In your opinion, how can we improve public awareness around nutrition and liver health — especially for conditions like fatty liver disease that often have no symptoms?

JL: First of all, thank you for highlighting this topic — this kind of coverage is critical. We need to empower patients with the knowledge that fatty liver disease is manageable — and even reversible — through diet and exercise.

Until very recently, there were no medications for fatty liver disease. The most effective “treatment” has always been lifestyle change: reducing added sugar, increasing fiber, moving more and losing weight if needed. When patients are given this information and support, many do succeed in reducing liver fat and slowing — or even reversing — scarring.

Is there anything else you’d like patients to know?

JL: Yes — nutrition and movement go hand in hand. If you’re trying to improve your liver health, combining healthy eating with physical activity is key.

For example:

• If you walk within 30 minutes after eating, you can blunt blood sugar spikes.
• If you’re eating more protein, exercise helps your body actually use it to build muscle.
• If you’re sedentary, start small. Add 10 extra minutes of walking a day. Track your steps. Increase gradually.

You don’t need to hit 150 minutes per week of exercise right away — just do a little more than you did yesterday. That progress adds up.

This transcript was edited for clarity.