Thursday, March 1, 2012

FAT

Let's talk about fat. All of the macronutrients are constantly being debated over. "Carbs are good!" "Carbs are bad!" "Fat is the enemy for fat loss!" Right? Not so much. You actually NEED fat just as much as you need carbohydrates, proteins and nucleic acids in your diet. Your cells are composed of a phospholipid bilayer (Any time you hear the word lipid, think fat.)

I think this picture of a typical cell membrane is great to show you how all of the molecules play a role in the functioning of our bodies. This is just one example, there are plenty more roles each macronutrient plays!

Did you know that " In the 1960s, fats and oils supplied Americans with about 45 percent of calories, only about 13 percent of adults were obese and under 1 percent had type 2 diabetes" Today as a whole, Americans are eating less fat than that (about 33 percent of our diet) yet 34 percent of adults are obese and 11 percent have diabetes, mostly type II. We're eating less fat now! What the heck happened? Research at Harvard University and others show that its not so much the amount of fat you take in that dictates this problem, but more so, the type of fat AND the number of overall calories consumed.


"Type" of fat? Isn't fat just fat? No way! Let's break it down:


Saturated Fats ("Ok fats")

  • Do NOT have carbon=carbon double bonds *this is key because there is no bend in the molecule (its just a 'straight chain'). Our bodies LIKE "kinks" or bends.
  • Most are solid at room temperature
  • Found in butter, cheese, steak, etc.
  • These fats are not as good for you as unsaturated fats, but they are definitely no where near as bad as trans-fats.
  • According to research at Harvard, "One highly-publicized report analyzed the findings of 21 studies that followed 350,000 people for up to 23 years. Investigators looked at the relationship between saturated fat intake and coronary heart disease (CHD), stroke, and cardiovascular disease (CVD). Their controversial conclusion: “There is insufficient evidence from prospective epidemiologic studies to conclude that dietary saturated fat is associated with an increased risk of CHD, stroke, or CVD."
Unsaturated Fats ("Good fats")
  • They can improve blood cholesterol levels, ease inflammation and stabilize heart rhythm
  • Predominantly found in foods from plants, such as vegetable oils, nuts, and seeds
  • Most are liquid at room temperature
  • Contain cis-carbon to carbon double bonds ("cis" denotes that the double bond is on the same side and furthermore it gives the molecules "kinks" or bends) Our body LIKES this orientation that the molecules are in. 
Trans-Fats ("Bad fats")
  • Contain trans-carbon to carbon double bonds
  • The "trans" part of trans-fats basically is telling us the molecules of the carbon=carbon double bond are on opposite sides. (Remember, cis was on the same side! Our bodies like "cis"!)
  • They make trans-fats because these products have a longer shelf life.
  • Made through hydrogenation.
Hydrogenation 
  • Hydrogenation is used to make margarines from oils. (turn liquids into solids)
  • Takes it from unsaturated to saturated. *this is key because we want unsaturated fats.
  • What happens is 2 Hydrogen atoms are added to the unsaturated molecule to break the double bond. Once the double bond is broken, the fat becomes a trans-fat and is more "like" saturated fat. (I say more LIKE saturated fat because its not exactly the same. Are butter (a saturated fat) and margarine (a trans-fat) the same? They are similar but not exactly the same, right?



Reasons to eat "Good fats" instead of "Okay fats":

  • "Eating good fats in place of saturated fat lowers the “bad” LDL cholesterol, and it improves the ratio of total cholesterol to “good” HDL cholesterol, lowering the risk of heart disease."
  • "Eating good fats in place of saturated fat can also help prevent insulin resistance, a precursor to diabetes."
BUT!...
It is not "better" to replace saturated fats with refined carbohydrates. You're better off eating the salami and cheese without the bread! As described above, your body NEEDS fats and saturated fats are not AS BAD as people once thought. Also, fats keep you full longer than carbohydrates (especially simple carbs!) Your body doesn't start breaking fats down until they travel to your intestines. (They virtually just go along for the ride until then!) 


Moral of the story: go for your "good fats"first then your "okay fats" and avoid trans-fats as often as possible.

How can I monitor my fat intake?
  1. Pre-measure your servings.
  2. Learn to decode labels to find those pesky "partially hydrogenated" fats.
  3. Make an effort to cook most of your own food. By cooking your own food, you have much greater control of how much fat or oil you are using.
  4. Don't be afraid to custom order at restaurants! "Hold the butter" "Sauce on the side" will help cut unnecessary fat!

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...