So how fast can you reverse fatty liver?

My husband was told he had fatty liver when he had an ultrasound done for another reason in March 2018. Looking back over his blood results, in retrospect it was no surprise. His ALT in December 2017 was 67 iu/l and in May 2016 it was 83 iu/l. Of course, back then I had no idea what that meant. In January, when he had a TIA, he had full blown metabolic syndrome, abdominal obesity, high blood pressure, so when the sonographer said about the fatty liver, we just shrugged – it was kind of expected.

He carried on the low carb and fasting that he started in February and 6 months and 10kg of weight loss later, in September, we got another ultrasound done. Just to see if there was an improvement.

Feeling hopeful.

Unfortunately the report still said ‘Mild fatty liver’. Bit disappointed. 10kg of weight loss and nothing had come out of the liver? Maybe it just takes longer than 6 months.

But something didn’t seem right with that idea. Several studies show that fatty liver can be resolved in a few weeks, or less. Here’s one that looked at the effect of a low carb diet on liver fat over 2 weeks (they didn’t even restrict calories). Check out the results:

reduced liver fat low carb
An Integrated Understanding of the Rapid Metabolic
Benefits of a Carbohydrate-Restricted Diet on
Hepatic Steatosis in Humans
Cell Metab. 2018 Mar 6;27(3):559-571.e5


So there’s a dramatic effect in 14 days, and that’s with a non calorie restricted diet. 

Here’s my other clue (start watching at 49 mins in):

This guy, Dr Robert Cywes is saying that he can reverse fatty liver with 48 hours of fasting, and he’s confirmed this with liver biopsy, which is the absolute gold standard.


Unfortunately he doesn’t appear to have published these findings, and I haven’t managed to find any other studies specifically looking at water fasting and the effect on liver fat. (If you find any let me know)

Well, my husband has done many periods of fasting over the period since February, ranging from a 16:8 intermittent fast to 12 days extended fast. BUT he had not done any fasts longer than about 20 hours in the few weeks approaching his second ultrasound.

So I thought, well let’s get him to do a slightly longer fast and see what the ultrasound scan looks like afterwards. Unfortunately its £99 a pop for an abdominal ultrasound, so I can’t afford to be getting them done left, right and centre. However,  I do some ultrasound examinations (on other body parts) as part of my job and figured I could learn to scan a liver well enough to see how fatty it is.  So one week later I scanned him again after 42 hours of water fasting.

Before I show you the results, here’s a crash course in liver ultrasound to assess fatty liver so you know what you are looking at:

uss learning
The label ‘rc’ stands for renal cortex, which is the meaty bit of the kidney.  To the top and left of the kidney is all liver tissue. What these images are showing is the comparison of how bright the liver tissue is compared to the outer part of the kidney (rc).  In a normal liver the kidney should be about the same brightness as the liver. In a fatty liver the liver is much brighter in comparison to the kidney.

Notice also the diaphragm. It is the bright white line in the bottom left hand corner of the first image above. It appears bright because the ultrasound beam can ‘see through’ the liver very well because there is no fat in the way. Contrast that to the second image – the line that is the diaphragm is faint and fuzzy, because the ultrasound beam cannot ‘see’ well through the fat above.


uss learning 2
Interpretation in normal language: 1. the area appears brighter than it should. 2. The deeper areas at the bottom of the image appear dark because the ultrasound beam can’t ‘see past’ the fat in the top of the image. 3. The line (vessel) should appear pure black, instead it is all fuzzy. 4. Means little areas of non-fatty tissue in a fatty liver.


fatty liver uss inage
Just another example comparing normal and fatty. Cirrhotic liver is something I never want to see……you’re headed towards liver failure at that point.

The Results

His first scan – 7th September

On 7th September, with no fasts longer than 20 hours for several weeks, these were my husband’s ultrasound images:

7th sept
It’s not great is it? You can see that brightness in the top half of the image – that’s fat (BAD).  Then it goes dark towards the bottom (BAD). The diaphragm (the white line at the bottom) is dull and fuzzy. (BAD)
7th sep1
You can see the same features here in the liver tissue which is on the left of the image. The big black bit in the middle is the gall bladder.

Its really unfortunate but the sonographer did not give us an image including the kidney to make that comparison between the kidney and liver. Shame.

His Second Scan

One week later, 15th September after a 42 hour fast, here’s the pictures:

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That diaphragm is much clearer and brighter, and the liver tissue is a more even brightness.
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07.30.38 hrs __[0006329]
This is the one with the kidney and liver together. You can see the rim of the kidney is a similar brightness to the liver tissue. This is GOOD NEWS.
So with the caveat that I’m not trained in liver sonography, I am prepared to say that there is a definite improvement after just 42 hours of fasting. I should mention that he did not change his diet in that week, he has been eating a low carb high fat diet since February with either one or two meals a day.

Was there complete resolution of the fatty liver? I may not be able to read the nuances of the ultrasound pictures well enough to say for sure. But the fact that the kidney and liver were the same brightness would point in that direction, I think. (Any comments welcome).

The Conclusion

So maybe the good Doctor Cywes was right. Maybe you can reverse fatty liver with a 48 hour fast. But then what happens afterwards? Lets go back to the study of the 14 day low carb diet. Remember how the liver fat dropped dramatically after just 14 days? But what happened next? Here’s a quote from the study:

"To test whether the marked reductions in liver fat were linked
to the diet intervention, we performed a follow-up MRS in seven
of the ten participants 1–3 months after completing the intervention
study and returning to their normal diet. We observed that
their liver fat content returned to a level similar to that measured
before the diet intervention (11.3% ± 1.6% at follow-up versus
13.8% ± 2.5% at baseline, p = 0.08)."

So fatty liver is quick to go, but quick to come back. What does this tell us?

The amount of fat in the liver is the result of this equation:

Fat going in    –   fat going out or being burnt      =     fat in liver

So a diagnosis of fatty liver just tells you what is happening to this equation at a particular moment in time. It can change rapidly. It makes sense that during fasting the fat in the liver will be burnt for energy or exported to other body tissues in VLDLs, and this might outweigh the fat coming in as FFAs from peripheral lipolysis. But you can’t fast forever. The equation needs to be balanced on a day to day basis.

The real question becomes: If a healthy person has a normal state of equilibrium where the fat going in balances the fat going out on a  day to day basis, what is the imbalance in NAFLD patients that results in the disequilibrium and liver fat build up?

Reversing fatty liver may not be the issue. Keeping it reversed is where it’s at.

Signposts to some great resources

Here is a collection of resources from some fantastic individuals that have helped me tremendously in my research:

Dr Jason Fung

Dr Jason Fung is a nephrologist in Canada who has pioneered fasting as a treatment for Type 2 Diabetes and Obesity. I highly reccommend his YouTube lecture series on the aetiology of obesity.  Watching this series was my ‘lightbulb’ moment when I realised that obesity was an endocrine dysfunction, not a question of ‘calories in, calories out’.


He has some great blog posts – here’s one about fatty liver:


Dr David Unwin

Dr David Unwin is a GP in the UK who has had tremendous success using low carb diets to help his patients – he talks about the effect of low carb diet on fatty liver disease here:


Chris Masterjohn

Prolific internet diet guru – big on ancestral diet and the benefits of that for our health. He has some excellent and thought provoking stuff on the role of choline and betaine in fatty liver disease:


Petro Dobromylskyj (Hyperlipid)

This dude has some intense science in his blog – you have been warned! His message is, pretty much, that Saturated fat is the saviour of your liver (and the rest of your body)

Also don’t cut yourself on the sarcasm, its sharp as hell. Great stuff.


Dave Feldman (The Cholesterol Code)

Dave Feldman is such an inspiration. His n=1 experiments in cholesterol have taken the low carb world by storm. His focus is lipids rather than NAFLD but the two subjects are intimately entwined in my view. I love Dave for planting the idea in my mind that high LDL could actually be a GOOD thing (*gasp*). Why is that relevant to fatty liver? Well LDL is formed from VLDL and VLDL is how fats are trafficked out of your liver – so do you want to transport fats out of your liver effectively?

Thought so. Read on and keep an open mind on the cholesterol thing……


That’s all for now 🙂




So what’s this all about then?

Just some thoughts and musings and useful signposts to information on fatty liver and what dietary strategies might be helpful to resolve it. Particularly focused on low carb, keto and intermittent/extended fasting, as this is the approach that led my husband to lose 20kg and come off his blood pressure medication in 6 months. However he still had some fatty liver – we are still working on that. So this is me sharing my research into NASH  and NAFLD and how to help. Please comment and contribute – would love your input.

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