Fats 101

First, check out my handout!

This has some excellent information about how fats are stored within the human body, functions for which they are utilized, and simple recommendations on how much to consume. Click to download here: Fat Facts 101

Now for a quick science lesson.

The basics:

Fat is one of three primary macronutrients (along with protein and carbohyrate) that fuels our bodies. The scientific name for fat is lipid, which is a cell comprised of smaller molecules known as triglycerides. Each triglyceride molecule contains three fatty acids attached to a glycerol molecule. Ok, Perri.. you’re bordering on a little too much science right now. Why is this even important? Great question! It’s important because when we talk about classifying fats, we are actually referring to exactly how these fatty acids are structured on a molecular level. The way each is structured can have very different implications on your health.

Saturated: These are called saturated because each carbon atom is single bonded to a hydrogen atom creating a straight fatty acid that can easily be stacked. These straight, stick “|” shaped molecules can be easily stacked on top of one another (Like this: |||), which is why saturated fats are solid at room temperature.

Unsaturated: Similar to a saturated fat, each carbon atom is bonded to a hydrogen atom, though one or more of these bonds is a double bond due to a missing hydrogen atom. Monounsaturated fats have one double bond within the fatty acid chain, while polyunsaturated fats have two or more double bonds present within a fatty acid chain. These bonds create a kink in the molecular structure causing them to look more “L” shaped, which is why unsaturated fats become liquid at room temperature.

Essential Fatty Acids: Also known as EFAs, Omega 3s and 6s are polyunsaturated fats that the body is unable to manufacture on its own. Therefore, they are essential to our diet. EFAs get their name based on the location of the first double bond within the fatty acid molecule (i.e. 3rd, 6th, 9th) Each of these, along with Omega 9 polyunsaturated fats, are critical components of health as they help reduce inflammation and makeup the fat cells within our brain. Omega 3s also contain special short and long chain forms, referred to as DHA, EPA and ALA, which our brains love! These are special because they act as antioxidants to help neutralize free-radicals and toxins. So, eat your salmon and take your supplements. Your brain and heart will thank you!

Cholesterol: These molecules are ring-shaped structures composed of hydrocarbons which are stored in the body as sterols. There are a few types of cholesterol, classified by size, that float around in your blood and ultimately impact your health. You’ve likely heard of LDL (this is the bad one) and HDL (this is the good one).  Ultimately, it is a waxy, protective substance that the body makes in response to inflammation and is critical for manufacturing hormones, creating strong cellular walls, synthesizing vitamin D, and regulating bile production. Cholesterol is found in animals only, and we NEED it! I’ll save this rabbit hole for another post, but eating egg yolks will not raise your bad cholesterol.

Source: 2.

**Remember, all fats that we consume are actually a combination of saturated, poly/mono unsaturated and EFAs, but we classify the sources based on which type of fatty acid they are mostly comprised of.

**Quick food for thought! Here is a short video about how canola oil is made. This is not a propaganda video, it is simply the facts. Click here to watch. Not as ‘natural’ as you expected, eh? (But actually, it’s terrifying.)

The truth about saturated fat.

Saturated fat has a bad rap as it’s blamed for causing cardiovascular disease. I’ll spare you the nitty gritty science this time, but plain and simple, saturated fat consumption is not the primary contributor to heart attacks. (For more information about cardiovascular health..click here.)  Here’s why.. recall from your science lesson that the term saturated fat means that all carbon atoms are saturated with hydrogen atoms. I think about it as a brand new white picket fence, like the one below!


(White Picket Fence — Image by © Benjamin Rondel/Corbis)

[Mono/Poly Unsaturated]

Alright, take a close look at each of these pictures. The top fence is a representation of a saturated fat molecule. The bottom fence is a representation of a mono or polyunsaturated fat molecule. Let’s pretend that you have just renovated your home, and included a nice new fence within your reno. Now, imagine a big summer storm comes through.. let’s compare this storm to heat, light and oxygen — each of which can oxidize, or damage, fat cells. Which fence would weather the storm? The brand new fence that is tightly bound together with sturdy nails and hinges, or the old, rickety fence which boards and nails missing? Hopefully you guessed the new one.. aka the saturated fat molecule.

A similar thing happens in your body. You’re cooking up a stir fry for dinner and deciding what kind of oil to use. Hmmm.. vegetable oil sounds appropriate since I’m sautéeing up some veggies, right? WRONG! As I just mentioned, heat is a huge offender when it comes to oxidizing fat. This means, that high heat breaks down a fat molecule and leaves it unstable. When unstable fat is absorbed by the body, it can become a free-radical cell and cause inflammation to healthy cells. Inflammation is one of the major construbution factors to increased cholestoerol. Over time, this eventually build ups to form plaques and leaves you at greater risk for high blood pressure, heart disease etc. (..but we will save the details of that information for another post.) My point is, chose the saturated fat when cooking. This molecule, refer back to our brand new fence, is much more stable against heat (..and light.. and oxygen). When it gets consumed, it remains a more stable molecule and our bodies eventually digest it into smaller components to be used for various functions throughout the body.

Are you still with me?

So, what should I be eating and cooking with?

The take home message here is to..

1. Eliminate and avoid ALL of the trans fats and highly processed oils. They aren’t doing anything for ya, and are actually causing a lot of harm.

2. Continue to include whole-food sources of unsaturated fats that are higher in Omega 3s & 6s, such as nuts, seeds, fish, avocado, olive oil..etc, but keep heating to a minimum.

3. Don’t be afraid of saturated fats! I am not suggesting to over do it and eat 6 slices of bacon every morning. But, just to be clear, (real, grass fed) butter IS better and grandma knew what she was doing saving the bacon grease.

4. Quality matters. Look for another post about the types of fat sources & brands I choose. Coming soon!

If you’re a visual person like me, then you may like this print out. Rather than reinventing the wheel, here is link to an excellent cheatsheet created by Diane Sanfilippo. She is also a certified nutrition consultant and the New York Times bestselling author of Practical Paleo (If you don’t have it yet, you miiiight want to consider purchasing it!).


1. Enig, Mary G. Know Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils and Cholesterol. Silver Spring, MD: Bethesda, 2010. Print.

2. Rolfes, Sharon R., Kathryn Pinna, and Ellie Whitney. Comparison of Dietary Fats. Image. Understanding Normal and Clinical Nutrition, Ninth Edition. Wadsworth, Cengage Learning, 2012. Print.

3. Sanfilippo, Diane. Practical Paleo (Updated and Expanded): A Customized Approach to Health and a Whole-foods Lifestyle. 2nd ed. N.p.: Victory Belt, 2016. Print.


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