We also hear a lot about the different kinds of fats. We are told to increase this type of fat, decrease that sort of fat and absolutely stay away from saturated or trans fats.
Once again, let’s define some of the terms used:
- Fats or fatty acids (FA) are long chains of carbon atoms linked to a specific number of hydrogen and oxygen atoms. The specific way the carbon, hydrogen and oxygen atoms are linked defines fatty acids.
- These FA can be saturated—meaning that each carbon atom is attached to another carbon atom with single bonds—or they can be unsaturated, meaning that at least some carbon atoms are double bonded to another carbon atom. Why is this important? Because UNsaturated fatty acids tend to be healthier fats. They can be monounsaturated, meaning there is one (mono=1) double bond—they are then abbreviated as MonoUnsaturated Fatty Acids or MUFAs. The PolyUnsaturated Fatty Acids or PUFAs have more than one double bond. These MUFAs and PUFAs are thought to be the healthiest fats.
- Hydrogenated fats or fatty acids refers to the chemical processing that adds extra hydrogen atoms to the FA making them the less healthy fully saturated fats. The REALLY unhealthy trans fats are a result of this chemical processing.
- One group of FA are called the essential fatty acids (or EFA) because humans cannot make them in adequate amounts for optimal health. The EFAs are the omega3 FA and the omega6 FA. The numbers 3 and 6 refer to the location of the double bonds.
- There is really nothing unhealthy about omega 6 EFAs. They are just everywhere, so it is relatively easy to get enough omega-6 EFAs.
- Omega 3 EFAs can be obtained through eating fish (tuna, mackerel, herring, salmon) and vegetables such as soybeans and soybean products (tofu, miso), walnuts and flaxseed. The key thing to remember is the ratio between the omega-6 FA and the omega-3 FA.
- Since we generally get enough omega-6 FA in foods, we want to increase the levels of the omega-3 FA. The goal is to have about three to four times as much omega-3 FA as omega-6 FA in the diet because that ratio seems to be ideal.
- Ancient humans –who had a much lower rate of cancer and chronic diseases, are believed to have eaten roughly same amount of omega-3 and omega-6 fats—studies indicate they ate about a 1:1 ratio. [1, 2] In some countries, people consume 20 times more Omega-6 than Omega 3! In those countries where the ratio of omega-6 to omega-3 is over 4:1, there is a corresponding increase in chronic disease. 
According to the World Health Organization and the Centers for Disease Control and Prevention, fats should make up anywhere between 20 and 35% of our calorie intake. Of this, roughly a third should come from saturated fats, another third from monounsaturated fats and the rest from polyunsaturated fats.
1. Wall, R., et al., Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids. Nutrition Reviews, 2010. 68(5): p. 280-289.
2. Innis, S.M., E.M. Novak, and B.O. Keller, Long chain omega-3 fatty acids: micronutrients in disguise. Prostaglandins, Leukotrienes, And Essential Fatty Acids, 2013. 88(1): p. 91-95.
3. O’Keefe, J. and L. Cordain, Cardiovascular disease resulting from a diet and lifestyle at odds with our Paleolithic genome: how to become a 21st-century hunter-gatherer. Mayo Clin Proc. , 2004. 79(1): p. 101-8.
4. Benatar, S.R., S. Gill, and I. Bakker, Global Health and the Global Economic Crisis. American Journal of Public Health, 2011. 101(4): p. 646-653.