In this final installment of articles overviewing the macronutrients (protein, carbohydrate, and fat) we complete the picture with fat. Everybody knows that fat is bad for you.  Right? Well, not exactly.  It is fat that has been most unjustly demonized.  We have been suffering from a low-fat craze for the last thirty years.  Everybody (well not really everyone!) has been convinced that fat is bad for us and should be avoided at all costs.  So what has happened?  We got fatter!  Obesity rates are going through the roof. 

So yes, we need fats.  They make up cell membranes and hormones, are required for absorption of the fat soluble vitamins (A, D, E, and K), are critical for infant brain development and the female reproductive system, and provide energy.  Ever wonder why everyone seems to have a Vitamin D deficiency these days?  Perhaps because they are not consuming the right fats for Vitamin D metabolism.

There are two types of fats – saturated and unsaturated (further defined as monounsaturated and polyunsaturated).  One of the easiest ways to tell them apart is that saturated fats are solid while unsaturated fats are liquid at room temperature.  Unsaturated fats are much more sensitive to oxygen, light and heat. 

This sensitivity underlies the critical nature of fat you need to understand.  When fats are heated or exposed to excess light and oxygen they oxidize.  It is dangerous when we consume oxidized fats.  Oxidation leads to inflammation which damages cells and is linked to a variety of diseases including heart disease.

Saturated fats are able to withstand greater temperatures before oxidation occurs.  The most susceptible fats to oxidation are the unsaturated fats, particularly the polyunsaturated ones such as vegetable oil, corn oil, soybean oil, canola oil, and cottonseed oil.  Note that margarine is made from various combinations of these oils.

Therefore, when cooking with fats and oils we want to use saturated fats such as butter, clarified butter (ghee), avocado oil, or coconut oil.  For salad dressing or other room temperature uses olive oil is best, followed by flax oil, pine nut oil, sesame oil or hempseed oil.

Another fat we hear of are trans-fatty acids.  These are formed during the process of hydrogenation.  Hydrogenation is used to “stabilize” vegetable oils so they will not oxidize and was initially developed to lengthen shelf life of processed foods.   

In the hydrogenation process polyunsaturated oils, usually corn, soybean, safflower, or canola, are heated to high temperatures and injected with hydrogen atoms.  During the heating process the nutrients in the oils are destroyed, the oils become solid and have oxidized. 

Trans-fats have been linked to many ailments, including cancer, heart disease, and reproductive problems.  Trans-fats are commonly found in commercial baked goods, cookies, crackers, margarines, vegetable shortenings, and processed dairy products. 

A very important classification of fats are the essential fatty acids, specifically Omega-3’s and Omega-6’s. These are polyunsaturated fats (so remember you do not want to heat them to high temperatures). We need all the essential fatty acids. The issue (like much of nutrition) is balance. The essential fatty acids are the precursors to prostaglandins – a form of hormones that support many functions including normal growth and the inflammatory response. They also assist in blood coagulation and circulatory functions.

Omega 6’s are generally considered “pro-inflammatory” while Omega 3’s are “anti-inflammatory.” Too much inflammation is linked to many chronic diseases, yet at the same time, our body requires inflammation as a normal function. Our body was designed to consume the Omega 3’s and 6’s in relatively equal amounts (you’ll see anywhere from 1:1 to 2:1 Omega 6’s to 3’s in the nutrition literature). Unfortunately, many Americans are in the 20:1 to 50:1 ratio. Why? Omega 6’s are found heavily in grains which we eat and feed to our animals and form the base of these diets.

Many of us have been encouraged to increase our consumption of Omega 3 essential fatty acids (found in fish oil).  These are EPA and DHA which are beneficial to the nervous system and the cardiovascular system.  They are important for normal growth of our blood vessels and nerves.  Omega 3’s have been found to decrease blood clotting, lower triglyceride levels, decrease blood pressure, and reduce inflammation in the body. 

Omega 6’s are equally important. The specific Omega-6 oils to consume include linoleic acid (LA), alpha-linoleic acid (ALA), gamma-linolenic acid (GLA), and conjugated linoleic acid (CLA). These fats are known to fire up your metabolism, enhance cell membrane structure and function, and synthesize eicosanoids.

If you want to learn more details regarding the Omega 6’s I strongly encourage you to ready Ann Louise Gittleman’s latest book Radical Metabolism which I have highlighted recently on my blog and in recent articles concerning healthy lifestyle and weight loss.

I recommend you eat these foods for healthy fat (organic preferred):

  • Butter
  • Extra Virgin Olive Oil
  • Virgin Coconut Oil and MCT Oil
  • Avocado Oil
  • Fresh Flaxseed oil or ground flax seeds
  • Hemp/hempseed oil
  • Chia seeds
  • Additional nuts and seeds: almonds, cashews, walnuts, pumpkin seeds, sunflower seeds, sesame, hemp – raw or dehydrated
  • Grass-pastured meat, poultry, eggs, and dairy (avoid dairy if lactose sensitive)
  • Wild caught cold water fish

Best sources of the essential fatty acids include: black current seed oil, evening primrose oil, flaxseed, lecithin, linseed oil, seafood (halibut, salmon, scallops, shrimp, snapper, and tuna), sesame seeds, sunflower seeds, walnuts, wheat germ, and winter squash.

Avoid these foods (the trans-fats and oxidized oils):

  • Margarine and other trans-fats
  • Vegetable oil, corn oil, soybean oil, canola oil, safflower oil, sunflower oil
  • Any highly processed and/or GMO oils

Bernard Rosen, PhD is a Nutrition Consultant and Educator. He works with individuals, groups, and at corporations to create individualized nutrition and wellness programs. His office is in Mequon, WI. To learn more or to schedule an appointment, e-mail at, call (262) 389-9907 or go to