Fats

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LIPIDS
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What are lipids?
FAT CELL

• main component in every living cell.
• Organic
• have carbon chains with attached hydrogen atoms
  and a carboxyl group at one end.

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Made up of C, H, O, just like carbs

• So whats the difference?
• STRUCTURE!

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Use of lipids in the body

• 1. Energy- 2 x energy of Carbs
• 2. Fat storage energy for later use
• 3. Shock absorbers for the vital organs

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4. Satiety value makes us feel full longer
5. converted to other compounds- hormones, bile,
Vitamin D
6. Insulates a fat blanket under the skin
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Three categories of Lipids

• Triglycerides fats oils
• Phospholipids emulsifiers, component of cell
  membrane
• Sterols bile, hormones, cholesterol

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Triglycerides
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Forms of Triglycerides

• Animal sources
• Butter
• Lard
• Eating different types of triglycerides can have
  different effects on the body.

• Plant sources
• Margarine
• Oils
• shortening

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Fat per day

• 30 of your calorie
• intake or less
• 9 calorie per gram

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• Women 19-49yrs 65 gms 16 tsp
• Men 19-49 90 gms 22 tsp
• 50 60 gms 15
• 1 tsp 4 gms fat

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• Fats and oils are made from glycerol and fatty
  acids.
• Each glycerol is attached to 3 fatty acids.
• They contain carbon , hydrogen and oxygen

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Carboxyl group -COOH
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• Each fatty acid consists of a hydrocarbon chain
  with a carboxyl group at one end.
• The glycerol molecule has three hydroxyl groups
  (OH), each able to interact with the carboxyl
  group of a fatty acid.

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Essential Fatty Acids

• Those the body must get through food.
• Can not make these in our bodies.

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Saturated fats

• Animal sources
• Fatty acids are saturated-hold all the hydrogen
  atoms they can.
• Solid at room temperature
• We make our own.

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Sources

• Animal products

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Unsaturated fats

• Most of the fatty acids are unsaturated
• have one or more double bonds between their
  carbon atoms.
• 2 carbon atoms missing a hydrogen bond join
  together
• unsaturated because they could hold more hydrogen
  atoms than they do.

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• Monounsaturated - lacks 2 hydrogen- has one
  double bond

• Polyunsaturated- lacks more than 2 hydrogen- 2 or
  more double bonds

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Monounsaturated fat
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Polyunsaturated fat
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• This prevents the fatty acids from packing close
  together and as a result, unsaturated fats have a
  lower melting point than do saturated fats. (they
  are healthier for you!)

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Trans fatty acids
Unsaturated fatty acids - one of two
shapes  "cis" and "trans." refers to physical
positioning of hydrogen atoms around carbon
chain. cis form is more common found in small
amounts in various animal products such as beef,
pork, lamb and the butterfat in butter and milk.
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Omega fatty acids

• unsaturated fatty acids
• first double bond counting from the opposite end
  from the carboxyl group.
• terminal carbon atom (shown here in blue) is
  called the omega carbon atom.
• monounsaturated fatty acid with its single double
  bond after carbon 3 (counting from and including
  the omega carbon) is called an omega-3 fatty
  acid.
• But so is a polyunsaturated fatty acid, such as
  linolenic acid (shown here), if its first double
  bond is in that position.

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Some studies have suggested that omega-3 fatty
acids help protect against cardiovascular
disease. This is known as Good Fat
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Omega-6 Fatty acids

• Omega-6 fatty acids belong to a group of "good"
  fats called polyunsaturated fatty acids.
• Help with immune system
• Relax

Good dietary sources of omega-3 fatty acids
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Hydrogenated Vegetable oil

• In hydrogenation, plant oils are exposed to
  hydrogen at a high temperature and in the
  presence of a catalyst, and turned from liquid
  into solid!

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• Occur when hydrogenation is done the unsaturated
  fats become saturated
• Hardened margarines

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• Good- Makes them resistant to oxidation- become
  rancid more slowly
• Good- makes them more stable
• Bad- makes them more saturated

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Functions of Triglycerides in Food

• Flavor make foods taste better
• Tenderize
• Emulsifiers
• Aeration traps air in bubbles

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Rancidity

• Oxidation of fat
• Fatty acids combine with oxygen and lose hydrogen
• Unsaturated fats with more double bonds are more
  prone to oxidation
• heat, light and oxygen speeds up oxidation

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• Rancid is the term that describes the unpleasant
  flavors that develop as fats oxidize
• Different chemical changes occur for different
  types of fats
• Rancid nuts, meats and potato chips all taste
  different

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Phospholipids

• Can dissolve in both fat and water
• Used as emulsifiers
• Found in eggs and peanuts
• Main component of cell membranes

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Sterols

• A fatty alcohol made from glucose or saturated
  fatty acids

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• strengthens cell membrane
• precursor of other steroids, including sex
  hormones.
• Vital for producing Vitamin D
• Used to make bile

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• Your liver produces all the cholesterol you need.
• Cholesterol in foods is useless
• It can make plaque which builds up on the walls
  of blood vessels

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LDL low density lipoprotein(bad)

• Carries cholesterol to to the body tissues to
  deposit there
• When elevated forecast heart and artery disease
• Oxidation of LDL causes damage to arteries

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Antioxidants

• Slows oxidation of LDL
• Vitamin C, Vitamin E, selenium are antioxidants

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HDL high density lipoprotein(good)

• HDL cholesterol- carries cholesterol away from
  tissue

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Olestra- artificial fat

• Remains undigested
• Passes through the digestive tract intact
• Causes diahrea and digestive upset
• Does not allow vitamins to be absorbed by the body