The Fatome
What is the Best Source of Fat on a Ketogenic Diet?

5 stars, average of 121 ratings

By KetoDiet Team, updated August 18 202384
This post may contain affiliate links, see our disclaimer.
Expert Article Evidence Based

Share Follow us 261.1k

Quick Summary tl;dr

The “fatome” is the unique balance of fats we each consume in our diets that influences our health.

Our optimal fatomes are unique to us and depend on our genomes, microbiomes, lifestyles, and nutritional perspectives.

The top 8 sources of healthy fats are extra virgin avocado oil, grass-fed beef, cacao butter, virgin coconut oil, ghee, extra virgin olive oil, macadamia oil, salmon and fish oil.

Table of Contents

What is the Best Source of Fat on a Ketogenic Diet?
What is a "Fatome"?
1. Long-Chain Saturated Fatty Acid Profile
2. Medium Chain Triglycerides (MCTs)
3. Monounsaturated Fatty Acids (MUFAs)
4. Omega-3 Fatty Acids
5. Smoke Points
6. Probiotic Effects
7. Dairy Sources
8. Whole Foods
9. Inter-omic Interactions
- Genome Example
- Microbiome Example
What is the Best Source of Fat on a Ketogenic Diet?
8 Sources of Healthy Fats on a Keto Diet

What is the Best Source of Fat on a Ketogenic Diet?

The ketosphere is pretty segregated, almost in a religious manner, on this issue. Some argue that we evolved to eat animal proteins and fats. This includes a higher proportion of saturated fats, which are stable and resistant to oxidation.

Others argue Mediterranean-keto is superior, given its high proportion of healthy monounsaturated fats (olive oil), Omega-3 fats (fish), and probiotic plant material, as well as the association between Mediterranean diets, longevity, and low rates of Alzheimer’s disease ( 1).

We come to the discussion with our own biases, often informed by our personal (and very legitimate) health journeys. But this piece isn’t about sticking to our guns; it’s about thinking critically to add nuance to the discussion and, at the same time, help you optimize your personal “fatome.” But, wait, what’s a “fatome?”

The #1 Keto Diet App

Intelligent Fasting Easily record or schedule fasting periods with our intelligent fasting tool. Auto Fill Automatically complete your day with meals and snacks that perfectly match your macro targets. Unlimited Meal Plans Create bespoke meal plans tailored to your preferences while hitting your macros. Trialed and Tested Recipes Enjoy delicious, foolproof recipes developed exclusively for KetoDetApp. AI Assistant Get instant answers to all your questions about the keto diet, the app, and more. Net vs Total Carbs Switch seamlessly between tracking net and total carbs at any time. Barcode Scanning Quickly scan product barcodes to track your food intake with ease. High Protein Keto Tailor your protein intake to support your fitness goals, from shedding stubborn pounds to building strong, lean muscle. iPhone & iPad Get Started for Free

What is a "Fatome"?

You’ve heard of the genomes and microbiomes. These are the unique sets of genes and microbes that fingerprint each of us and interact within our bodies to influence our health. Why shouldn’t we have a “fatome” — the unique balance of fats we each consume in our diets that influences our health?

The key word in the above paragraph is “interacts.” Each “ome” interacts in its own network and with the others. The genome, microbiome, and fatome all talk with each other. And, as with any team, the qualities of one player should complement those of the others.

In short, there is no one best “fatome.” We can’t tell you what your is, but we can nudge you down the road of self-study by providing the following background information to hopefully help you decide what fatty factors are most important to you.

1. Long-Chain Saturated Fatty Acid Profile

Not all long-chain saturated fatty acids are equal. Long-chain saturated fatty acids differ in the length of their tails, from 14 carbons to 22 carbons.

The three long chain fatty acids to focus on are 14, 16, and 18-carbon, myristic acid, palmitic acid, and stearic acid. In general, myristic acid and palmitic acid can decrease the expression of LDL receptors on your liver ( 2). This is not bad because it can increase LDL, it’s (potentially) bad because of how it can increase LDL. By decreasing LDL uptake at the liver, LDL in the blood has more time to get oxidized, condense, and become atherogenic. Steric acid does not decrease LDL receptor expression on the liver, which is good ( 2).

Therefore, saturated fat sources that have a higher “stearic acid to (palmitic acid + myristic acid)” ratio may, in some people, be preferable. (This is not a clinically proven fact; it’s simply forward-thinking speculation.) If you take a look at the list below, this would imply cacao (chocolate) saturated fat may be better than dairy fat, other factors being equal. #HighFatFoodforThought

Saturated fat sources that have a higher stearic acid to (palmitic acid + myristic acid) ratio may, in some people, be preferable.

2. Medium Chain Triglycerides (MCTs)

Medium-chain triglycerides (MCTs) go straight to the liver, rather than into systemic circulation. They can also drift into our cells’ mitochondria, without the need for transportation assistance. In short, this means that MCTs get used as more immediate fuel ( 3) and get turned into ketones more quickly than other fat sources.

Coconut oil is rich in MCTs, particularly the 12-carbon, lauric acid. (As an aside, there’s some controversy over whether lauric acid is a long-chain or medium-chain fatty acid. Based on how it’s biologically processed, however, it appears to be medium-chain ( 4)).

What are medium-chain triglycerides? MCTs get used as more immediate fuel and get turned into ketones more quickly than other fat sources.

3. Monounsaturated Fatty Acids (MUFAs)

Monounsaturated fatty acids (MUFAs), and their primary sources (olive oil, avocados, and macadamia nuts), many consider to be superfoods. Real extra virgin olive oil is perhaps the best fat source of antioxidant, anti-inflammatory polyphenols.

Avocados don’t have quite as many polyphenols as olive oil, but avocados themselves are packed with fibers and avocado oil has a great smoke point for cooking (more below) pro-inflammatory.

However, olive oil and avocado oil have a slight potential drawback: they are each 10-14% Omega-6. These pro-inflammatory essential fatty acids are fine (and unavoidable) to consume in moderation, but if you are like me and can consume over 1.5 Liters of olive oil per week, those Omega-6 can add up, potentially contributing to more harmful oxidative stress in the body.

So, if you’re Mediterranean-Keto, what do you do?

Here are two suggestions:

Add in more macadamia nut and macadamia nut oil, which are rich in MUFAs, but much lower in Omega-6 (only 2% vs. olive oil and avocado oil’s >10%).
I personally found that including some, but not too much, virgin coconut oil and raw organic coconut butter improved my oxidized LDL levels.

Most of the MUFAs in your diet will be oleic acid. Oleic acid is awesome because it gets converted into a metabolite called oleoylethanolamide (OEA) which activates the fat-burning transcription factor PPAR𝛼 and stimulates TRPV1 receptors on the vagus nerve to make you feel full ( 5).

There is, however, another (rarer) MUFA worth mentioning: palmitoleic acid, also known as Omega-7. Palmitoleic acid is richest in macadamia nuts, synergizes with Omega-3s (found in fish), and can help improve serum lipids ( 6), decrease inflammation ( 7), and increase insulin sensitivity ( 8). Omega-7 palmitoleic acid is also the founding member of the class of hormones called “lipokines” ( 9)!

Oleic acid helps fat burning and helps induce satiety. Palmitoleic acid (found in macadamia nuts) is a founding member of “lipokine” hormones that are good for the brain, heart, and tummy.

4. Omega-3 Fatty Acids

Fatty Fish (SMASH: Salmon, Mackerel, Anchovies, Sardines, Herring) are your sources of the Omega-3 fatty acids, EPA and DHA. You need adequate EPA and DHA for optimal health as both decrease inflammation. DHA is a major building block of the brain.

Land sources of Omega-3s, such as flax seeds and walnuts, only contain ALA. ALA can be converted into EPA and DHA, but only at extremely low levels. Therefore, you either need to have some fish in your diet or supplement with EPA and DHA in some form. This doesn’t need to be fish oils, if you are vegetarian. Fish get their EPA and DHA from eating marine algae. There are algae-based EPA and DHA supplements available as well. If you do supplement, krill oil is ideal because it contains a high amount of a special form of DHA (lyso-DHA) that’s best able to cross into the brain using a special transport system ( 10).

Adequate intake of EPA and DHA is important for optimal health as both decrease inflammation. DHA is a major building block of the brain.

5. Smoke Points

You ruin an oil if you overheat it. The most heat-resistant fat sources are avocado oil and ghee. Select your favorite (or alternate between both) depending on your personal preference. Most other oils, including olive oil, can be used for low-temperature cooking (see compare and contrast table). Never overheat fish or flax seed oils as they are among the most heat sensitive.

The most heat-resistant fat sources are avocado oil and ghee. Never overheat fish or flax seed oils as they are among the most heat sensitive.

I hope we can agree that it’s not just about IIFYM (“if it fits your macros”), nor it is simply about IIFYFAP (“if it fits your fatty acid profile”). Below are some additional factors to consider.

6. Probiotic Effects

Certain fat sources come with probiotic effects. Lauric acid ( 4) may help to kill off bad bacteria in your gut, while promoting good bacteria. Similarly, the fibers found in avocados and bacteria found in blue cheeses may each help to improve microbiome health.

7. Dairy Sources

Since I mentioned blue cheese, let’s talk dairy. In general, non-cow dairy sources are best. This is because cow dairy contains what’s known as “A1 casein,” which gets turned into an opioid in your gut that is pro-inflammatory and can cause constipation ( 11). Goat, sheep, and buffalo dairy are generally considered safer.

8. Whole Foods

Consider this: nature often packages fats in whole foods in a protective manner.

For example, the Omega-3s in salmon are healthy but fragile. That’s why wild salmon are pink! Yes. That’s why wild salmon are pink. When wild salmon are on their upstream marathon journey to breed, and exercising their little tails off, they generate a lot of oxidative stress. As a result, their bodies make “astaxanthin,” a potent antioxidant that protects the valuable Omega-3 fats.

When you eat wild salmon, you get the Omega-3 and astaxanthin (its bodyguard). When you eat only fish oil, you often don’t. That’s just one of hundreds of examples of how clever nature can be, which is why you always want to prioritize whole foods over packed foods or processed oils.

9. Inter-omic Interactions

Recall that we said everyone’s best fatome is unique. This is because all our other -omes are unique. We won’t delve into the interactions among the fatome and the genome, epigenome, transcriptome, proteome, metabolome, lipidome, microbiome, sociome and more (breath, Nick, breath). We will, however, provide you with two examples of what we mean by inter-omic interactions.

Genome Example

Take Alzheimer’s disease, the most common form of dementia and one of the greatest health burdens of our time. The major genetic risk factor for Alzheimer’s is the ApoE4 allele. This gene codes for a protein involved in the transportation and metabolism of fats.

People with ApoE4 tend to burn Omega-3s for fuel at higher levels ( 12), leaving less DHA for the brain to use for structure. Therefore, people with ApoE4 may do better with more fatty fish and marine sources of DHA in their diets.

The major genetic risk factor for Alzheimer’s is the ApoE4 allele. People with ApoE4 may do better with more fatty fish in their diet.

Microbiome Example

Do you suffer from constipation and bloating? Since irritable bowel syndrome impacts at least one-fifth of the world’s population (the constipation form is more common in females), I wouldn’t be surprised if this sounds like you. A common cause of these symptoms is the production of methane gas in your gut by methanogenic bacteria. This methane gas swells up your intestines, making you feel bloated, and also acts as a neurotransmitter to slow gastric motility and cause constipation ( 13).

How does this relate to your fatome? Well, these methanogenic bacteria produce methane using soluble fibers and “FODMAPs”. They also compete with Lactobacillus bacteria, which help you handle dairy. Therefore, methanogen-positive folk may not do well with avocados (soluble fiber and FODMAPs) or cheeses (even A2 cheeses).

But, you’re never powerless. The microbiome is dynamic. You can shift if through diet. Why not get clever? For example, when I found out that I have 500% and 900% the average levels of two major methanogenic bacteria (and very few Lactobacillus), I decided to cut my avocado habit (and fiber load) to help starve the methanogens, while slowly (very slowly) adding in A2 cheese to help grow the little population of Lactobacillus still hanging on for dear life ( 14). This is personal and incomplete experiment (time will tell) is just meant to illustrate that knowledge is power. Thus, having read this far, you now have more the power!

The bugs in your gut influence the fats you should eat. Different microbiomes need different "fatomes".

So, let’s return to the starting question...

The #1 Keto Diet App

What is the Best Source of Fat on a Ketogenic Diet?

I hope, by now you understand that the answer is not so simple. Your best “fatome” depends on your genome, microbiome, etc., lifestyle, and nutritional perspective. To help you start to ponder, we will leave you with some questions to help you reflect on what you just read:

Like saturated fat? Is it worth considering that not all saturated fats are created equal? Is it worth considering the stearic acid/(myristic + palmitic) ratio?
Are you Mediterranean-Keto? If so, could you be overconsuming olive oil and avocado oil? It is worth checking out macadamia nut oil (Thrive algae oil works too) and/or incorporating just a bit more saturated fat (virgin coconut oil, raw organic coconut butter, or ghee)?
Are you eating fatty fish, at least twice per week? Are you getting enough EPA and DHA? If you’re ApoE4, do you need more?
What oils do you use for cooking?
Are your fat sources mostly from extracted oils, or do they include whole foods?
Are your fats “extra virgin” (olive oil), virgin (coconut oil), and/or “raw” (nuts, coconuts, and dairy)?
And, finally, what self-experiments can you do to begin your quest to find your best fatome?!

The “fatome” is the unique balance of fats in our diets that influences our health. Our optimal fatomes are unique to us and depend on our genomes, microbiomes, lifestyles, and nutritional perspectives.