Fatty liver has gotten super-common of late. Roughly ⅓ of Americans have it.
It means just what it sounds like: Excess fatty deposits in your liver.
It’s now a leading cause of liver failure, and contributes to many other health problems — like liver cancer, diabetes, heart disease, and more.
The good news?
Fasting can effectively treat, and in many cases cure fatty liver. It even works pretty quickly.
Today I’ll explain what causes fatty liver, why fasting helps, and how you can get started. I’ll also share a few other tips for getting rid of fatty liver.
Let’s dive in.
What Causes Fatty Liver?
Alcohol used to be the main cause, by a long shot. But not anymore.
Over the past few decades, other lifestyle-related causes have shot way up.
As a society, we basically live on processed junk food nowadays. That kind of food is full of sugar and other refined carbs (which quickly break down into sugar inside our bodies).
Think of things like soda, juice, cereal, pop-tarts, pancakes, white bread, french fries, hamburger buns, cakes, cookies, candy, crackers, chips, tortillas, white rice, and the list goes on and on.
Here’s what happens when we consume processed carbs:
As the food gets digested and absorbed, its first stop is the liver. When the liver gets overwhelmed with tons of sugar all at once, it converts some of the sugar into fat right then and there, to help get rid of it. Hence the fatty deposits.
To further illustrate, in one study overeating carbs for 3 weeks caused a 27% increase in liver fat (while only increasing total body fat by 2%).
Basically, sugar turns your liver into a big greaseball. Which doesn’t exactly sound ideal. 😉
(Note: Perhaps counterintuitively, there’s no evidence that dietary fat contributes to fatty liver. For one thing, fat doesn’t even go to your liver after digestion, like carbs and protein do. It has its own special route.)
How Common is Fatty Liver Disease?
First, here’s some personal experience:
I see fatty liver all the time in the ER, and I’m not even looking for it.
About half the time when I order an ultrasound or CT scan of the abdomen, the report comes back with some funny-sounding phrases that basically mean the person has a fatty liver.
Something like, “Homogeneous increased echotexture could be consistent with hepatic steatosis…”.
Translation: Fatty liver.
Want some actual statistics?
Back in 2015, it was estimated that 30% of the US population had fatty liver, and 66% of people over 50 with diabetes or obesity had it.
Wow! That’s a lot!
Now, it’s surely even more common, because people keep getting fatter and sicker.
Why is Fatty Liver a Problem, Anyway?
So you have some fatty deposits in your liver. Why all the fuss?
First, fatty deposits make it so your liver doesn’t work as well, and contribute to something called “insulin resistance”.
Insulin resistance means you have too much of the hormone called insulin floating around in your bloodstream, which ultimately increases your risk of basically every chronic illness (like diabetes, high blood pressure, heart disease, infertility, Alzheimer’s, and many more).
So it’s kind of a big deal.
Second, and perhaps more obviously: Having a fatty liver can eventually lead to liver failure. Turns out, you can’t live without your liver, so liver failure is…problematic.
How Does Fasting Help with Fatty Liver?
As I explained above, the main cause of fatty liver is sugar (including processed carbs that become sugar in your gut). When you take away the sugar, it gets better.
How can you do that?
Either eat fewer carbs (such as a ketogenic diet), or sometimes eat nothing at all (i.e. fasting).
When you fast, various changes happen in your liver and the fatty deposits gradually go away…almost like magic. 🙂
In this video Dr. Jason Fung explains more about how we get fatty liver disease, and why fasting (and low carb) can help:
Until recently, there wasn’t much human research on this topic, so we mostly relied on anecdotes and basic physiology. But a study in 2021 showed that both low-carb diets and intermittent fasting can significantly improve fatty liver.
How Long Does it Take to Cure Fatty Liver with Fasting?
Naturally, it depends on a few variables, like how advanced your fatty liver disease is, and what type of fasting you do.
From what I can gather, it typically only takes a few days of water fasting to cure fatty liver, at least in the majority of cases.
To illustrate, last year I went to a conference and one of the speakers shared an anecdote about an abdominal surgeon who had all his patients fast for about 48 hours before surgery, to get rid of their fatty liver disease. And it worked.
Does it always go away that fast? We don’t have enough data to say for sure, but I suspect in the majority of cases it would go away within less than a week of water fasting.
If you’re doing shorter fasts, or just cutting carbs, you can expect it would take somewhat longer to reverse fatty liver disease. Probably weeks or months to see a significant change. But that’s ok. As long as you’re moving in the right direction, you’ll get there eventually!
Either way, doing some fasting is much better than waiting around until your liver stops working (or develops cancer, or you have a heart attack, or…)!
Fasting for Fatty Liver (How to Do It)
Here’s a basic rundown of how you can use fasting to treat fatty liver.
Intermittent Fasting to Reverse Fatty Liver Disease
Like any new habit, it’s best to start slowly with fasting. So I’d recommend you start with some easy, short-term fasts while your body gets adapted.
For example, you could start by skipping breakfast (or dinner) just once or twice a week, and gradually increase from there.
I won’t go into great detail about different intermittent fasting schedules here, or other related advice, because I’ve already done that elsewhere. For the full scoop, check out my Complete Beginner’s Guide to Intermittent Fasting.
Here’s the bottom line:
Any type of intermittent fasting is likely to help improve fatty liver, at least gradually.
Extended Water fasting to Cure fatty liver disease
I wouldn’t recommend you try prolonged, multi-day fasting without any preparation.
But when you’re ready, it can be an extremely effective tool for treating fatty liver disease.
As I alluded to above, even just a few days of water fasting will probably be enough to clear out the fatty deposits in your liver. At least in most cases.
Once you have a little experience with shorter fasts, consider trying a 24-hour fast once or twice a week. Then gradually work your way up to 36 hours, 48 hours, and so on.
I suspect a 3-day water fast about once per quarter would be enough to keep fatty liver at bay.
What Else Can Help With Fatty Liver?
Other than fasting, here are a few other things that help prevent or reverse fatty liver disease:
1. Cut the Processed Carbs
As I explained above, the main cause of fatty liver disease is excess consumption of processed sugar and other refined carbohydrates (which break down into sugar almost immediately).
Unfortunately, most people live on that sort of stuff nowadays. Our livers are constantly bombarded with sugar, some of which gets converted into fat inside the liver.
So in addition to fasting, another obvious treatment is to cut the carbs.
In other words, try eating a low-carb, high-fat diet for a while.
If you’re serious about curing or preventing fatty liver disease, I’d suggest you try a ketogenic diet for at least 2-3 months, to give your liver a prolonged break from all the incoming sugar.
Even if you don’t go completely low-carb, just by switching to mostly “real food” (i.e. stuff that isn’t crushed up in a factory), you’ll naturally reduce your overall carb consumption somewhat. And by definition, you’ll be avoiding processed carbs, which will certainly help.
Wondering how to get started with low-carb?
2. Avoid (Excess) Alcohol
This article is not so much about alcoholic liver problems, but alcohol is clearly another thing that contributes to liver disease.
Naturally, some people get too much sugar and too much alcohol. Margaritas, anyone?
Here’s the bottom line:
If you have any liver problems, you’re probably better off not drinking at all. But if you do drink, try to limit it as much as possible.
In case you’re interested, I explored a lot of other details about alcohol in a related blog post: Does Alcohol Break a Fast?
3. Have Some MCT Oil
MCT (medium-chain triglyceride) oil boosts ketone production, so it’s a useful supplement when fasting or on a ketogenic diet.
There’s also some evidence that MCT oil could help improve or reverse fatty liver disease.
Summary and Final Thoughts
Fatty liver disease is becoming increasingly common, and affects many people — adults and children alike.
The main cause is processed junk food. In particular, refined sugar and other simple carbs.
Having a fat-filled liver contributes to insulin resistance and many related diseases, and it’s a common cause of liver failure.
The good news?
Fasting and low-carb diets are both effective treatments for fatty liver. Use one, use the other, or use them together! A few days of water fasting can likely wipe those fatty deposits right out.
If you have a fatty liver, or you think you could be at risk…give fasting a try!
Your liver will be glad you did. 🙂