Friday, December 30, 2011

Factoid Friday: The Skinny on Nutrition, Part Two - FAT

I'm very sorry that I have let the holidays keep me from updating! I am glad to get back to Factoid Friday! Today we are continuing the three part Nutrition series on the major nutrients, with FAT!

Is FAT a friend or foe? Well, it just depends on how you have grown up seeing it. I have come to see fat as something I don't worry about much at all. I know a lot of you are going to have a hard time taking in this next sentence, but its very true. Fat doesn't make you fat! I know I keep alluding to a post that is going to explain this very complicated relationship between fat, carbohydrates, and hormones, and I promise it will be coming soon.
Until then, here is a quick overview of fat!


FUNCTIONS
Fat gives us energy, is an essential nutrient, it protects our organs, helps regulate temperature, covers nerve cells and provides the structural material for cell walls. In other words, we need fat to live.
Fat also serves as a back-up storage fuel for carbohydrates. We will burn fat when we do not have carbs/glycogen to burn. This is one of the reasons people have found success on lower carb diets. Most people think protein is what we burn, but it is actually a much weaker source of fuel for our body than fat. We will learn more about protein next week!

CHOLESTEROL
Ah, the dreaded word. Cholesterol is not a fat. It is a fat-related compound (a sterol) found in animal foods, such as egg yolks, liver, kidney, and meats. It plays many important roles, such as membrane fluidity and cellular signaling. Our body makes a small amount of it just in case we need it.

It is synthesized in the liver and linked with heart disease when consumed in excessive amounts. If you are someone who is prone to high cholesterol, than your diet should obviously be low in cholesterol. If you are a healthy person who does not already have a problem, keeping your total for the day around 300mg should be fine for you.


CLASSES of FAT
There are four classes of fats: (We will be concentrating on fatty acids).
  • Lipids - composed of fat and fat related compounds
  • Glycerides - a.k.a. triglycerides
  • Fatty acids - building block of fats
  • Lipoproteins - help move fats through the blood stream

FATTY ACIDS
When fatty acids are metabolized, they produce a large quantity of energy for our body. Many of our cells can use either glucose or fatty acids, and our hearts actually prefer to use fatty acids for fuel. I will explain each type and give you a Daily Recommended Intake value.

  • Saturated fats (<10%) - sources include animal fats, tropical oils - palm and coconut. These will raise your LDL (bad) cholesterol, and has no real effect on HDL (good) cholesterol.

  • Polyunsaturated fats (<10%) - sources include fish oil, veggie oils, and walnuts. These will lower your total cholesterol and also lower your HDL a small amount.

  • Monounsaturated fats (<20%) - sources include olive oil, canola oil, most nuts, avocado, pumpkin/sesame seeds and Omega 3 rich foods. These will lower your LDL, and have little effect on HDL, but most likely will increase it.

  • Trans Fats (<2g a day) - This is the bad one! The daily value should really be zero. These are basically any kind of processed food, margarine, or fast food that contains artificial ingredients, high fructose corn syrup, etc. They will raise your LDL and lower your HDL. We don't want any of that. PLUS the structure of these atoms are changed from the other fats and because of that, it reacts differently in your body.

I hope you will add some healthy fats to your diet and not let eating fat stress you out so much! As we have seen, your body needs fat to survive and function. Try adding a few monounsaturated fats in your diet this week!

Happy new year to you all!

'Til next time,
~Leslie

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