Dietary Fat

Dietary Fat

How FAT Functions in Your Body

 

Your body takes excess calories and stashes them away as fat to be used as reserve energy between meals.  Fat is continuously flowing in and out of your fat cells, and circulating around the body to be used as fuel.

Fat provides most of the fuel that our cells will burn for energy.  But your body will burn carbohydrates before it will burn fat in an effort to get your blood sugar levels down after a meal.  When you consume a carbohydrate and fat meal; the fat is delivered into the fat cells for storage, while the body works on the carbohydrates (glucose).  Cells burn this glucose for fuel and replenish their backup fuel supply (your muscles and liver will store some as glycogen).  Your liver will convert what is left to fat, and your fat cells will store it as fat.  As the blood glucose and insulin levels begins to decrease, the fat that was stored during the meal will be released from the fat cells and used for energy.

At rest and during low-intensity exercise, a high percentage of your energy is derived from fat.  With increasing exercise intensities, however, there is a gradual shift from fat to carbohydrate as the preferred fuel source.

If our body doesn’t remove the high levels of glucose from our blood (following a meal), it will circulate and start piling up in places where it doesn’t belong, such as your arteries, your liver, and elsewhere.  This can lead to type 2 diabetes and high blood pressure.

 

Average Body Fat Percentages

  • The normal female body-fat percentage is between 25 and 31 percent
    • The upper limit is 28%
  • Men can have up to 20% body fat in the normal range

 

Two Types of Body Fat

Subcutaneous Fat:

Subcutaneous fat is located directly beneath the skin (the kind you can pinch) and provides cushion and energy.

 Visceral Fat:

Visceral fat surrounds the internal organs in the gut.  Visceral fat tends to be much more metabolically active; meaning it emits more hormones compared to subcutaneous fat.  It can surround the liver, digestive tract, and other internal organs and impede their function.  It is also more prone to inflammation.  Excess visceral fat is the most dangerous kind of fat, and high levels of it is directly related to diabetes, heart disease, high cholesterol, and even dementia.

 

Comparing Apples & Pears

  • Apples:
    • Fat carried around the midsection
      • Usually have more visceral fat
  • Pairs:
    • Fat carried around the hips and thighs
      • Usually have less visceral fat.

 

Functions of Fat:

Every cell in your body is surrounded by a membrane that is composed of fat.  The membrane acts as a wall around the cell to confine the contents as well as give it structure.  It is also a protective shield, allowing nutrients, hormones, and metabolic by-products in and out.  Without fat, certain fat soluble vitamins, such as A, D, E, and K, would not be able to enter the cell wall and we would never receive their benefit.

 Fat also:

  • Regulates body temperature (insulation)
  • Insulates and protects organs
  • Protects nerve fibers and helps relay nerve impulses
  • Fuel for energy & energy reserves
  • Carrier for the fat-soluble vitamins A, D, E, and K & aids in their absorption
  • Supplies the essential fatty acids, linoleic (omega-6) & linolenic (omega-3)
    • Necessary for:
      • The formation of healthy cell membranes
      • Forms the fatty center of cell walls helping to carry nutrients across the cell membrane
      • Protects the integrity of the cell membrane
      • The proper development and functioning of the brain and nervous system
      • The production of hormones (Supply cholesterol for hormonal regulation)

Oh yeah!  Fat gives food that irresistible flavor, aroma, and texture that we love!  And it also promotes a feeling of fullness, or satiety after a meal.

 

The Role of Essential Fatty Acids

There are two main kinds of fatty acids:

  • Omega-3 (Linolenic)
  • Omega-6 (Linoleic)

Effects on the body:

  • Omega-6s are pro-inflammatory
  • Omega-3s have an anti-inflammatory effect

We need approximately equal amounts of omega-3 and omega-6 in our bodies.  But because of feeding our livestock corn and soy instead of grass; we are consuming huge portions of omega-6 and very little omega-3.  Consuming high levels of omega-6 raises our bad cholesterol, and keeps our good cholesterol low.

Consuming equal amounts of omega-3’s and Omega-6s raises good cholesterol and lowers bad cholesterol.