Tuesday, November 29, 2011

The Skinny on Fats in the Diet

After talking about body composition last week and how a high percentage of body fat can poorly influence overall health, I decided it was important to clarify the role of fat in the diet.  If you’ve been confused about what type and how much fat to include in your diet, you’re not alone.  Yet one thing is certain:  after many years of being told to avoid fat because it will make you fat, we now realize that fat is absolutely necessary as part of a healthy diet, and if eaten sensibly, will help to keep you lean and looking and feeling good. 

In general, our diets should include approximately 20 – 35% calories from fat.  So for example, in a 2,000 calorie/day diet, this would amount to 400 – 700 calories.  At 9 calories per gram, this converts to 44 – 78 grams of fat per day.   If that sounds like a lot to you, consider why fat is so important in the diet: 

  • It’s a source of concentrated energy
  • It is a major structural component of cell membranes
  • It’s a source of insulation
  • It’s necessary for healthy skin and nails
  • It slows down digestion
  • It’s needed to absorb fat-soluble vitamins and nutrients
  • It keeps our vision strong
  • It’s involved in cell signaling
  • It’s a major component of the central nervous system and necessary for proper brain function

As you can see, fat wears many hats in the body and it’s important to include it in some form at every meal.  But what kinds of fats should I be eating, you may ask?  In general, we need a combination of saturated fats, unsaturated (mono- and poly-) fats, and essential fatty acids in the diet.  

Although we’ve been led to believe that saturated fats lead to elevated cholesterol levels and heart disease, in his extensive study of primitive cultures, Weston Price found that saturated fat was an integral component of a number of diets supporting excellent health, development, and vitality.  This includes the addition of animal fats in the forms of butter, eggs, full fat dairy products, and the fats from animal tissue.  However, with our relatively sedentary lifestyles today, I recommend that they be eaten in small amounts.    

Still, many others believe that only unsaturated fats should be consumed.  However, high consumption of polyunsaturated fats, which are more unstable than saturated fats, in the forms of commercially available oils, such as corn, safflower, and soybean can lead to inflammation in the body that underlies diabetes, heart disease, cancer, digestive disorders, and premature aging.   Therefore, these fats should be used sparingly too. Hydrogenated, or trans fats, often found in processed and packaged foods are another source of unhealthy fat that can promote inflammation. 

To make fat part of a healthy diet, consume foods that already contain healthy fats since they are naturally protected in their whole state.  These include nuts, grains, legumes, eggs, fish, fruits and vegetables, and clean sources of meat.  Butter, ghee, grapeseed, and coconut oils have high smoking points so they are great for sautéing.   The benefits of extra virgin olive oil are preserved when used at low heat.  A high quality olive oil works well for drizzling on foods, in dressings and as a dip for breads. Nut and seed oils are also best used unheated as a condiment on vegetables and grains.   Here are fats to include by category:

Saturated Fats:
  • high quality or organic dairy products such as fermented yogurt, kefir, or raw cheeses, organic butter
  • eggs from pasture-raised chickens than were fed organic feed (antibiotic- and hormone-free)
  • grass-fed, wild, organic meats and poultry raised without hormones, antibiotics, or grains produced with pesticides
  • unrefined coconut oil
 Monounsaturated/polyunsaturated fats:
  • extra virgin olive oil
  • high quality canola oil
  • grapeseed oil
  • avocado
  • nuts and seeds and their oils
 Essential Fatty Acids:
  • ALA (omega-3) - flax, walnuts, hemp, tofu
  • LA (omega-6) - sunflower, pine nuts, pecans, brazil nuts, sesame oil
  • EPA/DHA  (long-chain omega-3) - herring salmon, black cod, anchovies, mackerel, tuna, halibut, herring, small amount in poultry and egg yolks, algae
 Image courtesy of m_bartosch 

No comments:

Post a Comment