Thursday, July 8, 2010


I'm going to be the first to admit that I am not a fan of fats as a subject. Americans are obsessed with fat! (Yes that is a liberty bell made of butter). Every few years we hear a new version of how we're not supposed to eat certain types of fats or fats at all. The low-fat diet, fat-free foods, no saturated fats, no trans-fat, all omega-3 fats. No wonder we're so messed up about fats!
I maintain that people have been eating a balanced amount of a variety of fats for centuries and if we were just left alone to eat how we like to eat (without lobbyist or media 'inspiration'), we'd probably be a lot healthier.

Enough of that tirade! Let's debunk fats. There are so many you hear about. Here's a basic list of fats that you might hear you need or should avoid: 
Saturated fats
Short-chain saturated fats
Monounsaturated fats
Polyunsaturated fats
Trans fats
Cholesterol (not a fat!)

Basics first: what is a fat? A fat is actually a fatty acid. One end of the molecule is highly charged and is very soluble in water. The other end of the molecule is a large chain of greasy atoms that are fat soluble. They basically look like this: 
This fat is a saturated fat. The one below is an unsaturated fat.
Red meat is rich in long-chain saturated fats. Coconut oil is rich in short-chain saturated fats. There are pros and cons to both. 

The pink box highlights what's called a double bond. This give the fat unique properties that make it less sticky and more rigid. When there is one double bond, it's called a monounsaturated fat. When there are multiple double bonds (like the picture below), it's called a polyunsaturated fat.
See how it completely changes the shape so it's no longer a straight line?

Ok, we're almost to the end of the chemistry lesson. Then we'll talk about food, I promise! So, what are omega-3 and omega-6 fats?
The omega is the very end of the fatty acid, and then you number the points as you move toward the acid end of the fat. Like this:
On the double bond closest to the end matters. So, if you have to count to three before you run into the double bond, it's an omega-3 fat. THEN STOP COUNTING. That's an omega-3 fat. Here are some examples.

They have many double bonds, but they are defined as omega-3's because of the one labeled 3. Omega-6's look like this:

These are found in a variety of foods.
Omega-3's are found in: Fish, Krill, Chia, Kiwi, Flax, Walnuts, Pecans, and Hemp. 

Omega-6's are found in most plant sources and the meat of animals that eat grains. They say American's eat too many omega-6's because they make up our cooking oils: palm, soybean, rapeseed, and sunflower oils are all really rich in omega-6's. 

 All of those fats are naturally found, and they are all nutritious when eaten in moderation. There is another class of fats called trans fats. Trans fats are mostly man made, although some plants do make very small amounts of them naturally. It's unclear at this time whether the plant trans-fats are dietarily available or if they are too integrated with the cell walls of the plants. Anyway, trans fats are mostly man made, and they are made when a polyunsaturated fat is made saturated (the double bonds are removed) by a chemical process called hydrogenation.

Trans fats were invented to improve the storage of plant-made fats. Plant-made polyunsaturated fats can 'go bad' and become rancid when they are exposed to oxygen. For processed, shelf stable foods, it's very important that the fats are as stable as possible. If the fats go bad, the food product will taste bad.

Trans fats appear to build up in the body and are associated with a variety of illnesses.

That's all for now. I hope you learned something, and if you want to know more just ask!


  1. I love this post. Anytime I can understand terms that people throw around left and right, I'm happy. I feel like such an informed eater...

  2. Awesome post. It makes me more interested in different omega-3's and what their different mechanisms of action (and health benefits) are. Q's: I just opened a jar of tahini that supposedly expires in 2012, but the oil layer on top smelled possibly rancid to me. Why do rancid fats all kind of smell the same? And what does eating rancid fats do to one's body/how are they assimilated (or not)?