Saturated Fat, Insulin Resistance & Liver Fat [NAFLD]

Saturated fat has become something of a hot topic in the world of nutrition discourse, but when it comes to fatty liver disease the evidence seems to be pretty clear.

It ain’t great.

But let’s elaborate on that, shall we?

Of course, if you are looking for a resource to help you manage NAFLD my brand new book, The Essential Diet For Fatty Liver Disease, is a wonderful option.

The scientific articulation to follow in today’s article is the same you can expect from the book, which is available to pre-order by clicking through the image below.

Now let’s get to the good stuff.

What I’m mostly interested in exploring here today is how saturated fat intake interacts with fatty liver disease both in terms of potential effects on liver fat storage and insulin resistance, two of the most important considerations in the management of this common condition.

Statistically speaking, the top sources of dietary fat in the “average” North American diet include:

  • Beef and other red meat
  • Cheese, and certain cheese heavy dishes ( think Italian, Mexican cuisine)
  • Butter
  • High %MF dairy products
  • Ice Cream
  • Processed meat like sausages, ham, hot dogs
  • Chips, cookies, cakes, pastries
  • Pizza

Now the first strong indicator we have that these types of foods are not helpful for those living with fatty liver disease is that the low saturated fat Mediterranean Diet pattern, which I’ve written about previously here, shows the best potential for those living with fatty liver disease to reduce liver fat accumulation, reduce inflammation and to improve insulin sensitivity.

These are all the things we want in NAFLD, and remember that this style of eating is naturally very low in saturated fat.

In fact, the relationship between saturated fat intake and insulin resistance has been noted in experimental studies from 20+ years back.

From here, let’s take a look at what some of the latest scientific papers have found about the relationship between saturated fat and fatty liver disease.

PLoS Medicine 2016

Found that replacing saturated fat with polyunsaturated fat ( equivalent of swapping beef with fish, let’s say) reduced insulin resistance in multiple human studies.

Journal Of Endocrinology And Metabolism 2019

Found that, all else equal, saturated fat intake increased liver fat accumulation as compared to different types of dietary fat which prevented accumulation.

Frontiers In Nutrition 2021

A review article which identified saturated fat as one of the biggest dietary risk factors for worsening liver fat accumulation and insulin resistance in NAFLD.

Diabetes Care 2018

An experimental study which found that, when provided as excess calories, saturated fat increased liver fat accumulation by 40% more than other fat types (MUFA).

Nutrients 2016

Found that, in those living with NAFLD, the people who had the highest dietary saturated fat intakes also tended to have higher liver fat content.

Saturated Fat & The Mitochondria

The totality of the evidence points strongly towards individuals living with NAFLD to reduce their saturated fat intake to improve their health.

But why is this?

One of the current scientific hypothesis, as explained in this scientific paper, is that saturated fat negatively affects the mitochondria (a component of human cells).

Our mitochondria have a very important role to play in metabolizing fat and so if their function is compromised, one could see how this failed breakdown of fatty acids could then become problematic and theoretically, potentially lead to increased liver fat storage.

It should be noted as well that a relationship also exists between proper (or improper) mitrochondrial function and insulin resistance.

The explanation above is obviously a gross oversimplification, but gives some indication into where current science is headed.

Which leads to the final component of today’s article.

L-Carnitine & Fatty Liver

Carnitine is a naturally occurring compound that helps transport fatty acids to your mitochondria for further breakdown.

Given the potential role of the mitochondria in fatty liver disease, as per the discussion above, scientists have become interested in whether or not supplementing with carnitine can help those living with fatty liver disease.

There is very limited evidence that it might.

A systematic review and meta-analysis of five experimental studies (found heredetermined that L-carnitine supplementation ranging from 500-2,000 mg per day had the potential to modestly reduce liver fat, liver enzymes and insulin resistance in those living with NAFLD.

More and better studies will be needed before strong claims can be made, but certainly findings like this will help pave the way forward.

In terms of supplements, omega-3 fatty acids (DHA/EPA) and synbiotics ( Pre+Probiotics) have much more evidence of benefit at this stage.

Delicious Recipes With Low Saturated Fat?

My new book has you covered, but just to whet your appetite here are some previews:

Trout & Black Bean Taco Bowl [Fatty Liver Friendly]

 

High Protein Chocolate Mousse [5 Ingredient, Vegan]