I’ll be taking a much needed rest by spending Thanksgiving week with my family. Because of this, I figured I would repost one of my first blog articles exploring dietary fats.
Fats are the most misunderstood macronutrient.
The major confusion regarding fat stems from the word itself. There are fats you eat (dietary fat) and there is body fat (adipose tissue). Consumption of dietary fat does not directly increase body fat but, since both phrases contain the word fat, there is a concern that one affects the other.
Fats are found frequently in nature in animals and fish, nuts and seeds, fruits such as avocados and coconuts, and oils.
Fat is more calorically dense than carbs or proteins. Fats have 9 calories per gram while the latter only have 4. This is great when only eating two or three meals a day and trying to keep energy steady, but, calories in versus calories out will affect body weight.
Fat is essential for life. It is necessary to assimilate vitamins A, D, E, and K. It is one of only two fuels that power the body efficiently. Fats are used for the construction and maintenance of cells within our bodies.
Let’s look at the different forms of fat to understand where the beneficial features lie and where the fearful stigma may come from.
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First, a quick chemistry note: fats are made up of carbon, hydrogen, and oxygen atoms bonded together.
Saturated fats are named because every carbon atom is “saturated” with hydrogen; there are no double bonds. This makes them very stable, meaning they are the safest for cooking and the least likely to oxidize. Another interesting fact is that they make up half of our cell membrane structure.
These are found predominately in animal and fish products but are also in coconut and palm oil.
Monounsaturated fats contain one double bond between two carbon atoms meaning they are fairly stable but still subject to oxidization. Maybe you’ve noticed when cooking with olive oil, if you turn your back for a moment, it will start to smoke. Similarly, if you leave a cut avocado out, it will start to turn brown. If consumed in a raw form, in a timely fashion, these can improve cholesterol levels within the body.
These fats occur in plant foods such as avocados, nuts, and olive oil.
Polyunsaturated fats contain two or more double bonds meaning they are unstable and prone to oxidization and rancidity. It’s not a great idea to overheat or overfill our bodies with such an unstable substance. It’s not a particular macronutrient group but rather the process of oxidization that really damages our bodies.
So, eliminate all polyunsaturated fat, right? Again, when it comes nutrition and the human body, things just can’t be that simple.
Remember those essential fats I mentioned last time…Omega-3 in particular? That’s a polyunsaturated fat! The key is to balance your sources of polyunsaturated fat intake.
O-3 is essential for life so incorporate wild-caught seafood into your diet (algae and flax can be used by vegans but keep in mind that the type of O-3 provided by these plants sources, ALA, is only converted at around 6% to EPA and 0.5% to DHA, which are the forms our body needs).
Another polyunsaturated fat, Omega-6, is also essential but it is found abundantly in nuts, grains, soy, and oils (and any animals fed these foods too). O-6 is so prevalent the average American consumes 20 times more O-6 than O-3. This is problematic because, being an easily oxidized poly fat, the body can quickly accumulate too much O-6 leading to inflammation and increasing risks of cardiovascular disease. An optimal ratio for O-6 to O-3 would be 2 to 1.
For the sake of comparison, let’s look at two healthy foods – salmon and almonds. One ounce of salmon has 550mg O-3 while the almonds have 3500mg O-6. When I have almonds, I can eat 4 handfuls (one handful is about one ounce) before I even pour them into a bowl and sit down. This means, just in that one day, if I consumed nothing else containing O-6 (nearly impossible), I’d have to eat close to a pound of salmon.
I’m not recommending you count every milligram…just increase intake of certain foods (wild-caught fish or grass-fed beef), consume some in moderation (nuts, oils, avocados), and avoid others altogether (soy, corn, and other modern vegetable oils).
Trans fats are the most dangerous type of fat. These are formed through chemical modification and are unrecognizable to the human body. They will inevitably be stored as abdominal fat or fat around the internal organs (the deadliest form of fat in the body).
These fats are found in processed oils, butter-replacements, and other packaged goods. Basically, if the word “hydrogenated” is anywhere on the package, do not consume it under risk of death!
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I hope this was a helpful review of basic nutritional science. Remember, if we set aside emotional responses or preconceived notions and rely solely upon science, we can’t go wrong!
Enjoy Thanksgiving 2014!