The Skinny on Dietary Fats


While dietary fats are often given a bad reputation for their high calorie content, these energy dense molecules are actually classified as a macronutrient (along with carbohydrates and proteins) and are an essential component of several body functions.  For example, fats play a major role in the structure of every single one of your body cells.  They are also a key component used in the synthesis of prostaglandins, chemical substances similar to hormones. Lastly, dietary fats are used for energy.  While carbohydrates are most often credited for providing our bodies with easily accessible energy, dietary fats lend slower burning, more sustained energy.  Therefore, it is important not to eliminate or restrict fats from our diet.

The key to reaping the health benefits that fats have to offer without over-doing our daily energy needs is choosing the right ones.  It is important to understand that not all fats are equally nutritious.

Unsaturated fatty acids are extracted from plant and some animal sources, and are found naturally in oil form.  Unsaturated fatty acids can be polyunsaturated (PUFA) or monounsaturated (MUFA).  These fats tend to also be called “healthy fats,” and encompass omega-3-fatty acids and omega-6-fatty acids.  Omega-3 and Omega-6-fatty acids are considered essential fatty acids (EFA’s), because our bodies cannot manufacture them, and therefore they must be obtained from the foods that we eat.  Food sources of omega-3-fatty acids and omega-6-fatty acids, as well as other healthy, unsaturated fats include:

Omega-3

Omega-6

Other PUFA and MUFA

flaxseeds

flaxseeds

olive oil, especially extra-virgin

soybeans

soybeans

canola, sesame, and soybean oil

walnuts

walnuts

peanuts and peanut butter

canola oil

safflower oil and sesame oil

almonds and almond butter

dark green leafy vegetables

sunflower seeds

avocados

cold water fish (cod, salmon, tuna)

pumpkin seeds

brazil nuts, walnuts, hazelnuts, and cashews

     

Fats that naturally occur in animal products are referred to as saturated fatty acids, and are found in solid form.  Diets high in saturated fats are linked to high cholesterol values, and possibly a higher risk of heart disease and some forms of cancer later in life.  This is not to say that saturated fats should be avoided, but consumed in moderation.  For those of us who are not vegetarians, animal products with that contain saturated fats also contain other essential nutrients such as iron and B-vitamins, and are important sources of protein.  We should, however, choose leaner cuts meat and lower fat dairy products, as well as remove the skin from poultry to reduce the amount of saturated fats in our diets.

Lastly, there is one type of fat that does not occur in nature but can be found in our pre-packaged cookies, cakes, and snack foods.  Trans-fatty-acids are manufactured to prolong the shelf life of such items, but when consumed in large amounts can be dangerous to our health.  Diets high in trans-fats are linked to an increased risk of heart disease and stroke, as well as developing type 2 diabetes later in life.  Trans-fats should be restricted from your diet as much as possible.    

Fat Facts:

  •  One gram of fat contains 9 calories; that is more than twice the caloric value of carbohydrates and protein (both contain 4 calories per gram). 
  • Of all the calories consumed in one day, 20-35 percent of them should come from fats. 
  • Less than 10 percent of total daily calories should come from saturated fats.
  • No more than 2 grams of trans fat should be eaten per day.

Eating a balanced diet with appropriate amounts of monounsaturated and polyunsaturated fats, enjoying saturated fats in moderation, and avoiding trans fats whenever possible supports good health, keeps our bodies functioning correctly, and provides energy and satiety.

-Amanda

          

Sources:

http://www.functionalmedicine.org/content_management/files/ifm_Dietary_Fats_091503.pdf

http://www.health.gov/dietaryguidelines/dga2005/recommendations.htm

http://www.webmd.com/diet/guide/good-fat-bad-fat-facts-about-omega-3

http://www.heart.org/HEARTORG/GettingHealthy/FatsAndOils/Fats101/Trans-Fats_UCM_301120_Article.jsp#.Tx7EY28S2Ag

                

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