Fat is confusing stuff. We hate it on our body, yet love it in our mouth. In general we don’t think it’s healthy, but now we’re not so sure? We’re told some kinds of fat are “super foods” which save you from every ill known to mankind, while others kill you. (Don’t even THINK about passing Go!) So yes, if you’re confused by fat and/or would like to learn why you actually should eat more of the stuff, this post is for you!
What is Fat?
This is probably a decent place to start. Just what is this luscious substance we both love and loath? For starters, fats are composed of carbon, hydrogen, and oxygen atoms. The amount of hydrogen atoms present determines the amount of “bonds” existing between the carbon atoms. The amount of bonds between the carbons determines the “type” of fat. Stick with me here. (Pun intended).
There are two parent categories of fats: saturated and unsaturated. In saturated fats, all the carbons are fully “saturated” by hydrogen atoms, so each carbon is only connected to each other by a single bond. Unsaturated fats, on the other hand, feature less hydrogen atoms, which the carbons make up for by creating “double bonds” with fellow carbons. One double bond creates a monounsaturated fat, while multiple double bonds creates a polyunsaturated fat. The more carbon double bonds, the more fluid the fat.(Think of the bonds as being “bendy” places in the fat chain.) These double bonds are also less 
stable and easily react with oxygen, or “oxidize.” In other words, they easily go rancid.
And while foods are often categorized as one type of fat (i.e.: animal fat is “saturated” and olive oil is “monounsaturated”), most foods are actually comprised of multiple types of fat. See this nifty chart! (I could stare at it for hours!)
SATURATED FATS
Oh saturated fats! The poor vilified scapegoats of the low-fat health world (Can I get a sigh?) Check out my post on the matter if you fancy larning about the politics of saturated fats, but let’s just look at the basics, shall we?
Saturated fats are found mostly in butter and animal fats. They contain no double bonds: all the carbons in the fatty acids are “saturated” in hydrogen atoms. They are solid at room temperature and very stable. (You don’t have to worry so much about them spoiling or oxidizing, including in your body). Saturated fats contain fat soluble vitamins like K, A, and D. They make up 50% of the body’ cell membranes, and support calcium, vitamin, and essential fatty acid synthesis. While saturated fats do elevate cholesterol, they raise both HDL and LDL, rendering them benign in the grand scheme of things.
Don’t fret about eating saturated fats if you’re following a Paleo approach. They’re healthy, stable, not inflammatory,
and yummy!
MONOUNSATURATED FATS
Monounsaturated fats are found in many nut, seed, and fruit oils, like olive, sesame seed, and safflower oil. Interestingly, they also constitute a good percentage of animal fat as well. About 30% of butter and almost half of lard (AKA bacon fat!) is monounsaturated fat. Monounsaturated fats contain one “double bond” between fatty acids and are typically liquid at room temperature, but may gel or solidify when cooled. While not as stable as saturated fats, monounsaturated fats don’t go rancid as easily as polyunsaturated fats. They are a nice alternative to trans fats and the inflammatory Omega-6 polyunsaturated fats (see below) which define our modern diet. Monounsaturated fats may support good cholesterol levels, and reduce risk of breast cancer, heart disease, and stroke.
I’ve found that monounsaturated fats tend to get ignored in the Paleo sphere, a community often focussed on defending saturated fat while showing the damage done by Omega-6 polyunsaturated fats (see below). As such, monounsaturated fats often fall by the wayside. They’re healthy. Eat them!
POLYUNSATURATED FATS Â
Polyunsaturated fats are abundant in fish, nuts, and grains. (As such, they constitute a huge portion of the modern diet.) They contain more than one double bond between fatty acids. They’re pretty much always liquid, and easily oxidize (or go rancid.) Polyunsaturated fats are a double edged sword in that they can be both super awesome, yet super damaging. It all goes back to those ever famous Omega-3 and Omega-6 fatty acids. Allow me to explain.
Polyunsaturated Essential Fatty Acids (EFAs)
There are two specific types of polyunsaturated fats required by the body, which the body cannot synthesize on its own. You must get them from the food you eat, no way around it. These are linoleic acid (LA) found in the polyunsaturated Omega-6s, and alpha-linolenic acid (ALA) found in Omega-3s. While both are required, Omega-6s are inflammatory, while Omega-3s are anti-inflammatory. Let’s say that again! Omega-6s are inflammatory, while Omega-3s are anti-inflammatory. One more time! Omega-6s are inflammatory, while Omega-3s are anti-inflammatory.
Omega-6s are abundant in processed seed and vegetable oils (like corn, peanut, and soybean), while Omega-3s are found in flaxseed, walnuts, and fatty fish (particularly salmon, herring, sardines, and oysters.) Conventional meats contain more Omega-6s, while grass-fed meats feature more Omega-3s. So most people tend to eat way more Omega-6s than Omega-3s. (And which ones are inflammatory?)
EFAs make up cell membranes throughout the body, from immune cells, to red blood cells, to cardiac and neural tissue. They affect the cells’ flexibility, fluidity, and activity. They’re pretty important stuff! EFA deficiency can lead to skin rashes, stunted growth, dampened immune system, vision problems, and declined cognitive functioning.
The Omega-6:3 Ratio
Historically, we consumed Omega-6 and Omega-3s in a 1:1 ratio, maximizing benefits and discouraging negative effects. Our modern processed diet rampant in grains and vegetable oils, however, yields an estimated 16:1 Omega-6:3 ratio. Scary stuff. Since the cells of our body are literally made of these essential fatty acids from diet, a skewed Omega-6:3 ratio causes a shift towards a cellular foundation of inflammation. This encourages every inflammatory problem you can imagine, from cardiovascular problems, to autoimmune diseases, to cancer. Omega-3s, on the other hand, are anti-inflammatory and protective against such conditions. Studies show they decrease cardiovascular diseases, diabetes, and mortality rates in general. They may help with inflammatory conditions such as rheumatoid arthritis and inflammatory bowel disease (IBS). Omega-3 deficiencies may even play a part in the development of psychiatric disorders such as bipolar disorder and depression. In fact, pregnant women may experience postpartum depression (characterized by sleep difficulties, crying, fatigue, and loss of appetite) because the fetus utilizes his or her mother’s Omega-3 fatty acids for developing brain and nervous tissue.
And to make things more complicated, there’s this whole EPA & DHA business. While most Omega-3s (the good stuff!) consumed in today’s diet are the aforementioned ALA from vegetarian sources like flaxseed, the specific type of Omega-3 found in fatty fish is actually the long chain EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA and DHA provide more potent health benefits than ALA, so consuming Omega-3s from fatty fish is the ideal route to follow.
MEDIUM CHAIN TRIGLYCERIDES (MCTs)Â
Medium Chain Triglycerides are a type of saturated fat found primarily in coconut and palm oil. They’re the darling of the Paleo world, with an almost neverending list of stunning benefits. Unlike the other saturated and unsaturated fats which must be broken down in the intestines to be used as energy and stored as fats, MCTs are sent directly to the liver for energy. As such, they act kinda like “carbs” in providing instant fuel, yet without the insulin spike! MCTs also encourage ketone production, an energy substrate supporting the body in general, but particularly the brain. MCTs can discourage fat gain, decrease appetite, up-regulate fatty acid use, enhance thermogenesis, and regulate insulin. They support the immune system and absorption of calcium and magnesium. They can act as antioxidants, reduce cholesterol, and protect against a myriad of diseases, such as cirrhosis, pancreatitis, Crohn’s disease, and malabsorption in newborns.
Plus coconut oil just tastes delicious! You can add it to salads, veggies, or meats, or even eat it plain! Buy the virgin, unrefined version. I like the Trader Joe’s and Whole Foods’ brands of unrefined coconut oil. They’re both relatively inexpensive as well.
TRANS FATS
Trans fats are bad news all around. These are chemically modified fats in which normally liquid vegetable fats are “hydrogenated,” meaning their hydrogen atoms are tweaked in order to make the fat more solid and shelf stable. Since they can withstand high temperatures, trans fats are often used in
 the food industry for frying. They’re also resistant to spoilage, and thus are abundant in processed foods, baked goods, and “low fat” or “fake fat” foods like margarine.
The problem? Trans fats are just really bad for you, basically enacting all the bad stuff
that saturated fats were “supposed” to do. They raise bad cholesterol and lower good cholesterol. They encourage inflammation and insulin resistance. And unlike saturated fats, they actually do increase risks of heart disease and diabetes.
Thankfully, a Paleo diet effectively frees you from these sneaky devils, so you shouldn’t have to worry about them!
ReferencesÂ
http://bodyecology.com/articles/6_benefits_monosaturated_fats.php#.VDmPnUsmwYU
http://www.nature.com/ejcn/journal/v53/n7/abs/1600783a.html
http://authoritynutrition.com/optimize-omega-6-omega-3-ratio/
http://www.sciencedirect.com/science/article/pii/S0140673694925801
http://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/trans-fat/art-20046114
http://lpi.oregonstate.edu/infocenter/othernuts/omega3fa/
http://www.med.nyu.edu/content?ChunkIID=21809
http://www.mayoclinic.org/healthy-living/nutrition-and-healthy-eating/in-depth/fat/art-20045550
