Whereas cholesterol usually gets the gold for most demonized nutritional substance, fats undoubtedly take the silver. We recently covered the cholesterol conundrum, and this week it’s time to confront the fervor over fat. Thanks for joining us today. Please make yourselves comfortable.
As you know, I’ve always been a friend to many fats. But the fact remains, ladies and gentlemen, that not all fats are created equal.
A few fats, including but not limited to trans fats, deserve every bit of disparagement they get and then some. However, we feel for those other little guys in the group. Many of them are, assuredly, a good lot, and we’d like to put in a good word for them.
Everyone ready? Servers are coming around with crudite platters as we speak. Let’s begin, shall we?
Fats are compounds of carbon, hydrogen and oxygen atoms that exist in chains of varying lengths, shapes and orders. They’re one of the vital nutrients required by the body for both energy and the construction/maintenance of “structural” elements, such as cell membranes.
Although all fats to some extent contain both saturated and unsaturated fatty acids, they are generally categorized by levels of saturation. Moving on…
The Monounsaturated Fats

Biochemically speaking, these fatty acids sport a single double bond in their fatty acid chain. The more double bonds a fatty acid boasts, the more “fluid” it is. They are generally liquid at room temperature.

Monounsaturated fats are found in numerous oils, including olive oil, flaxseed oil, sesame seed oil, sunflower oil, safflower oil, corn oil and peanut oil. Notice that we use the word “found” and not comprise. The fact is, these oils contain varying levels of monounsaturated fat. The rest is a mix of polyunsaturated and saturated. Olive oil, for example, contains about 75% monounsaturated fat, and canola 60%. By the way, these fats are also found in avocados and nuts. They’re granted approval (as much as any fat is in conventional wisdom) as a “healthy fat.”
(Excuse me. May I cut in here please? Yes, I’d like to announce that we will be deconstructing some of this “healthy fat” assertion shortly. Thank you. Carry on.)
Poly in the Cracker? The Polyunsaturated Fats

Can you guess? Polyunsaturated fats have, yes, more than one double bond in their fatty acid chain. They tend to be liquid even when refrigerated. Their problem is they also tend to go rancid easily, particularly when heated. Yup, it sounds nasty, and you should see it! Free radical damage galore. When we heat them (and we often do), they often become oxidized. We’ve let in the Trojan Horse at that point and opened ourselves up to all kinds of free radical pillaging – everywhere from cell membrane damage to wrinkles to arterial plaque build up.
Polyunsaturated fats are found in grain products, soybeans, peanuts and fish oil. Fish oil and grain products in the same category! Say it isn’t so! (Heightened whispers and shuffling.)
Let’s all take a breath. There’s more to the story.
Enter Essential Fatty Acids!

First off, we call them essential because the body can’t produce them itself and must obtain them from food. We’re talking about omega-3 and omega-6.
Omega-6. It’s important, I fully acknowledge. Omega-6 fatty acids, found in corn and other grains as well grain-fed livestock, play a crucial role in dermal integrity and renal function among other things. But if left unchecked, they run amok, and spur inflammation. Egad! Ratio matters, but we’ll get to that in a minute.
What keeps these guys in check? Why, omega-3s, of course. Ignored for decades by the medical establishment, they’re finally garnering respect, but it’s still not enough in my opinion.
![]()
Omega-3s are found primarily in fish, algae, flax and nuts. You also find good portions of them in eggs from chickens that are fed fish or flax meal. And you’ve heard us go on and on about the three forms: ALA (think flax) as well as EPA and DHA (think fish oil). Omega-3s aid circulation by naturally thinning the blood, fight systemic inflammation, support brain function and ease symptoms of depression, anxiety and even ADHD. (Nods of approval)
Now back to the ratio matter. Estimates vary, but experts generally characterize Western diets as anywhere between 10-30 parts omega-6 to 1 part omega-3 (10-30:1). What ratio should we be getting? What did our primal ancestors likely eat? Try 1:1. Although many in the establishment will try to tell you that 4:1 is good enough.
This takes us back to the question of lean meat. If you recall, my reasoning in offering some support for lean meats (in lieu of fattier meats that our ancestors ate, as a number of you reminded me) was the fatty acid ratio of the fat in modern meat. Grain-fed meats are much higher in omega-6 fatty acids and lower in omega-3 than grass-fed meats, but not everyone has access to grass-fed meats. The best way to combat the plethora of omega-6 is to watch your ratios and to consume more omega-3s.
Yes, folks, we’re a long way from healthy here. The sky high ratio of typical Western diets sets us up for inflammation, high blood pressure, blood clots, depressed immune function and sub-optimal brain development and neurological function. Egad, is right.
And so we return to the question of all those “healthy” monounsaturated and polyunsaturated fats. There’s more to the question than the big CW tells you. The omega ratio of “monounsaturated” soybean oil? Anyone, anyone? It’s 7:1. Corn oil? It’s 46:1. (Audible gasps, clutching of pearls, adjustment of jackets)

So, what about the other oils? What about olive oil? The ratio for olive oil is 3:1, which isn’t great in and of itself. But there’s yet another wrinkle. Olive oil is 75% monounsaturated and 14% saturated, which means that only 11% of it has the polyunsaturated ratio to begin with. In these relatively small amounts, ratio isn’t as much of a concern, particularly when the oil contains so many other good compounds like polyphenols that fight inflammation damage caused, in part, by the problematic ratio. Corn oil, on the other hand, contains only about 25% monounsaturated fat (and 13% saturated). The ratio matters big time here.
The Saturated Fats

Ah, good old saturated fats. You seem so easy in comparison. CW makes you into a monster, but we see you more in the light of King Kong-powerful but sympathetic, misunderstood. You’re among friends here.

Before we move on, we can’t forget the chemistry note. Saturated fats have all available carbon bonds paired with hydrogen atoms. I know, not the most interesting, but the important part here is that they’re highly stable. They don’t have the same tendency toward rancidness as polyunsaturated fats, even if heated. This is a good thing.
I’ve been brazen enough to recommend saturated fats, found in animal products and some tropical oils, as part of a healthy diet, and I’ll say it again. Saturated fats serve critical roles in the human body. They make up 1/2 of cell membrane structure. They enhance calcium absorption and immune function. They aid in body’s synthesis of the essential fatty acids and provide a rich source of fat soluble vitamins.
Last but not least, they provide cholesterol. Yes, the human body makes its own anyway, but it all balances out. Can I help that I’ve been won over by its many charms? Naturally occurring substances, natural body processes appeal to me – unlike our next categories.
Trans Fats

We’ve all heard the story by now. The unnatural chemical modification process that created trans fats made products more shelf stable but has wreaked havoc in the bodies of those who ingest them. (Quick fact: the hydrogenation process changes the position of hydrogen atoms in the fatty acid chain.)

The body doesn’t recognize the transformed fats and, innocent as it is to snack food chemists’ intent, doesn’t know to eliminate it. The trans fats are absorbed through cell membranes, where they initiate general disorder in cell metabolism. Downright unsavory, if you ask me.
Trans fats, banes of our existence that they are, have been associated with inflammation, associated atherosclerosis, diabetes, obesity and immune system dysfunction. And it turns out they’re bad for your profile.
A study out some months ago showed that trans fats caused a “redistribution of fat tissues into the abdomen… even when total dietary calories are controlled.” Kidding about profiles aside, abdominal fat (i.e. apple shaped body) has been associated with the build up of fat around internal organs, which has in turn been associated with a higher risk of heart disease.
Interesterified Fats
“What are these?” you ask. Good question. Insteresterified fats are a new breed of chemically modified fats created to avoid the trans fat label now reviled and even outlawed in some cities. Like trans fats, these fats go through a kind of hydrogenation process along with the associated rearrangement of fat molecules and an enrichment with stearic acid. (Anyone licking their chops yet?) The point is the same as it was with the trans fat poison, er process: it makes the product more shelf stable.
So, this sounds all too familiar, no? Sound like splitting hairs? You got it. (Insert your own expletive.)
My suggestion: if hydrogenated is mentioned anywhere on the label, run like mad.
Now get this. Research is showing that the effects are not just similar to trans fats but worse. Turns out these fats “may raise blood sugar levels even more than trans fats.” Just what we need in this country! The researchers suggest that this new fat actually “alters metabolism in humans.” (General commotion, a few calls to action.)
Ladies and gentlemen, thank you for your generous attention. I say we open the floor for questions and discussion.
ms.Tea, Hulagway, C’est moi!, Slice, Mykl Roventine Flickr Photos (CC)
Further Reading:
The Definitive Guide to Cholesterol
The Definitive Guide to Insulin, Blood Sugar and Type 2 Diabetes
60 in 3: Fat is Bad! Fact of Myth?
Sponsor note:
This post was brought to you by the Damage Control Master Formula, independently proven as the most comprehensive high-potency antioxidant multivitamin available anywhere. With the highest antioxidant per dollar value and a complete anti-aging, stress, and cognition profile, the Master Formula is truly the only multivitamin supplement you will ever need. Toss out the drawers full of dozens of different supplements with questionable potency and efficacy and experience the proven Damage Control difference!
Prefer listening to reading? Get an audio recording of this blog post, and subscribe to the Primal Blueprint Podcast on iTunes for instant access to all past, present and future episodes here.
[tags]fat, monounsaturated, polyunsaturated, trans-fat, intersterified, omega 3, omega 6, fatty acids, olive oil, saturated, cholesterol[/tags]
If you'd like to add an avatar to all of your comments click here!
Leave a Reply
266 Comments on "The Definitive Guide to Fats"
GREAT post Mark!!!!!
I have a few college buds that this is being sent to now 😉
Marc
EXCELLENT article….
so i know this is a dumb question but what is a reommended daily amount of fat and saturated fat?
For now, the USDA reccomends that 20-35% of calories come from fat, and 10% of calories come from saturated fat. That means 45-77g total fat and <22g saturated fat, but what they didn't take into consideration was beneficial saturated fats like lauric acid (found in coconuts) or stearic acid (found in dark chocolate)
Loved the article – very informative.
What is the people’s take on Saturated fats from dairy products (specifically pastuerized stuff?)
What is a good ratio of o3:o6:saturated:mono:poly? 🙂
Fascinating stuff! Very informative and comprehensive. You answered so many questions I’ve had, I can’t think of any more to ask! Well, about fats anyhow. Thanks for the heads up about the interesterified fats – hadn’t even heard of those yet.
There are a lot of ‘perfect omega 3 to 6 ratio’ supplements out there these days. It’s a bit of a shame that the makers of these supplements don’t think further than their own product..
So when it all boils down, are these (extra)fats which I include in my lifestyle the best?
Olives, olive oil, coconut oil, avocado, tehina, flax seeds, hemp seeds, and occas nuts (walnut, pecan, almond, mac, brazil). Then I guess the meat fat from grassfed or org meat and a rare dash of toasted sesame oil in a stir fry!
Do you have any thoughts on fractionated oil? Obviously not the healthiest thing in the world since it is highly processed, but is it the same sort of not healthy as trans and interestified fat?
Outstanding Article! Eating nuts, fish, and eggs is a great way to get Omega 3. My fav. breakfast, Cooked egg topped with cashew butter. Don’t be afraid of “good” fats, just watch the “calories.”
Mark, thank you for this most entertaining and informative look at fats…I learned a lot!
Great post. I think it’s funny how “fat” has become so hush, hush. It’s ironic that the recommended nutrient intakes call for more of our calories coming from fat than protein. Great job of showing how we still need some fat in our diets. Here’s something I’ve been wondering for a while, but keep forgeting to research though … Does anybody know the difference between virgin and extra virgin olive oil?
virgin olive oil is just mechanically pressed, to squeeze out the oil, as opposed to using solvents or heat to bring out oils. extra virgin olive oil goes thru some testing to make sure it is of highest quality
Actually, in the US the answer is much simpler than that: nothing. There are absolutely no legally enforced requirements here (though there are, laughably enough, voluntary guidelines) to label olive oil “extra virgin”, as opposed to “virgin”, “olive pomace oil”, or “excess grease from processing equipment, as long as it’s principally derived from olives”. Assessment of olive oil processing and quality is a very big deal in Europe (see International Olive Council), but anything you’ll get in the grocery store here will be varying degrees of garbage they couldn’t sell at a good price there (see Capitalism).
The worst oils will have the best labels and containers.
Dan –
We have a Definitive Guide Post on Oils scheduled for sometime in the next month or so. Stay tuned!
After reading this, I have a question. When cooking, does it make more sense to use saturated fat, such as butter, instead of oil?
Because, according to the definitive guide to fats, mono and poly unsaturated fats found in oil are more likely to form free radicals when used to fry something on a skillet or bake something in the oven.
Yes, actually, using a saturated fat like coconut oil is safer. The double bonds in poly fats are more apt to form trans fats when heated to high. Monounsaturated fats like olive, peanut, and canola* can tolerate moderate temperatures on the stove.
*Personally, I don’t recommend canola oil, i’ve heard some pretty nasty things about it, it has to go thru a lot of processing and chemical extraction to detoxify it to humans. And free radicals form. Never again will I buy canola oil
Excellent post! Thanks!
VAS yes! you should only use ploys for low heat cooking. I only add it at the end. I use coconut oil, butter, bacon fat, etc for cooking. Coconut oil is the best.
All commercial oils, in my opinion, should be avoided as they are heat processed. These include soy, corn and cannola.
Great article and thoroughly researched. I especially appreciate that you added some chemical drawings for an increased understanding.
[…] Mark’s Daily Apple we have this guide to fats. I’ve never seen such an amazing amount of useful information all in one place and in a very […]
[…] week’s Definitive Guide to Fats gave us a chance to unpack the essential fatty acids. But we thought they deserved a closer look […]
What exactly is “low heat” and “high heat” cooking?
I use a tablespoon of olive oil when I bake chicken. It usually cooks @ 400 degrees for 30 to 40 minutes.
How much fat to consume while in ketosis?
And also from Type 2 diabetic point of view?
[…] The Definitive Guide to Fats […]
[…] with the phrase “good dog,” but that’s for another post (or blog altogether?). Anyway, as we’ve established before, fat is generally a healthy, nay, the healthy source of fuel for all followers of the Primal […]
[…] The Definitive Guide to Fats A few fats, including but not limited to trans fats, deserve every bit of disparagement they get […]
[…] are under stress (who isn’t), eating too many sugars and other carbs, trans and hydrogenated fats, or drinking alcohol, or when we are exercising inappropriately. Theoretically, that still ought to […]
[…] are under stress (who isn’t), eating too many sugars and other carbs, trans and hydrogenated fats, or drinking alcohol, or when we are exercising inappropriately. Theoretically, that still ought to […]
[…] Mark Sisson’s definitive guide to fats. […]
[…] a low carb diet, with the bulk of your carbs in a post workout meal/snack, and fuel your body with healthy fats you will see wonderful changes in body composition and have the energy you need to get through the […]
What about Dairy products?
Good or Bad?
Bad! Paleolithic man had no access to milk since animals were not domesticated and would have eaten him before he was able to steal the milk. The human genome suffers from lactose intolerance because it has yet to evolve to accept it.
how can we eat butter if we can not drink milk?
Being lactose sensitive myself, I was very happy to learn that cheese and butter have much lower lactose concentration than milk. During fermentation, bacteria take care of consuming most of that yummy sugar leaving behind a product that is nearly lactose free. This only applies to cultured butter though. Traditional butter is still low on lactose, but for a different reason: As the milk fat is separated from water, a big part of the lactose is left behind.
what about mommy’s milk?
Very nice article. I’m not completely elucidated yet. I would love to see two things to help me get organized about my eating efforts: 1. a chart-view summary of fat types organized by priority of healthfulness and providing examples of food types per fat; and 2. perhaps a separate post altogether on oil types (walnut, olive, grapeseed, vegetable, etc.) and a similar chart-view summary. Those would be absolutely priceless…
Mark? 😉
*high five*
Excellent article, as always. I’m a bit of an idiot but that made perfect sense to me and I’ll be using it to inform my eating habits from now on.
You are so brave to recommend saturated fats. You know what works and aren’t afraid of the establishment. Way to go!
I live on saturated fats.
http://curiousfarmer.wordpress.com/meat-diet/
[…] Want to know more about fatty acids? Check out Mark Sisson’s Definitive Guide to Fats […]
[…] immune systems. On the other hand, any intake of trans and hydrogenated/partially hydrogenated fats will compromise immunity, as will excessive intake of the Omega 6 fats found in many vegetable […]
[…] arms flailing, gnashing their teeth. Let’s set the record straight here. You know our decidedly pro-fat leanings. No need to go any further there. But what else is there to like about beef? To its credit, beef […]
Great article and very informative.
We need to break free from junk science, and realize that FOOD is good for us, where man made stuff is not. Fat, carbs, and protein are essential for us to survive.
I wish that the “establishment” would quit contradicting themselves.
It “appears” (strong emphasis on “appears”)that all the flip-flopping is just a mere a coincident to a next release of diets, food systems, books, and talk show appearances.
All well intended and in our best interest of course.
[…] The Definitive Guide to Fats […]
[…] successfully cut out all vegetable oils and fake butter spreads in favor of grass-fed meat and real fats, there are still a couple reasons – other than for cardiovascular health – for you to […]
[…] speculate (and do we ever) on why carbs are not-so-great from purely a gene-expression POV, on why fats are our “healthy friends” from an evolutionary biology perspective and why proteins should form the basis of a fat-burning, […]
[…] The Definitive Guide to Fats […]
[…] successfully cut out all vegetable oils and fake butter spreads in favor of grass-fed meat and real fats, there are still a couple reasons – other than for cardiovascular health – for you to […]
[…] here, you may want to subscribe to my weekly newsletter. Thanks for visiting!The posts involving omega-3s have spurred a lot of discussion and a good number of excellent questions. Thanks to Ed Parsons and […]
[…] plenty of saturated and monounsaturated fat. Fat blunts insulin secretion while increasing testosterone production. Insulin may be useful for […]
[…] Fats […]
[…] proves that it’s not good any more. Hey, that sounds like Conventional Wisdom. (Remember how fats were good for a million years, then they were bad for a few decades, and now they are good […]
[…] most people, and don’t obsess over calorie counting (in either direction). Focus on saturated and monounsaturated fats (with some fish oil to supplement) and take in about a gram of protein for every pound of lean body […]
If we are trying to keep a balanced ratio of 3:6, should we stay away from “healthy” monounsaturated fats like olive oil, nuts, avocados? It seems like we want to eat wild fish, pasture raised eggs and meat, cook with saturated fats (coconut oil, lard, ghee, butter) and limit our intake of olive oil, nuts, and avocados because they will raise our 6 ratio. Is this correct?
[…] enough omega-3 fats can cause an inflammation response in your body. You can read more about that here. When shopping for pickles at HEB, many of them had high fructose corn syrup listed as an […]
[…] Eat good fats! – Mark’s Daily Apple tells you why they are good for you here […]
[…] an overall review of FATS, from unsaturated to saturated to trans to poly, here is your […]