Contemporary Nutrition Chapter 5 Lecture Outline

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Chapter 5
Lipids
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Fats are organic -structure similar to CHO and
Protein (C, H, O) -Carbon bonds are more
energetic making them twice as
calorically dense Fat in food can be
visible or invisible
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Fatty Acid

• Simplest form
• Composed of a chain of carbons

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Food Sources (Fig 5-3)

• Fig. 5-3

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Properties of Lipids

• Do not readily dissolve in water
• Fats are solid at room temperature
• Tend to be of animal origin
• Oils are liquid at room temperature
• Tend to be of plant origin
• Triglycerides are the main form of lipids in food
  and body (storage)
• Energy dense (9 kcal /gm)

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Functions of Lipids

• Provide energy/Efficient storage of energy
• Insulation/Protection
• Supply Essential Fatty Acids
• Transport fat-soluble vitamins
• Formation of Cell Membranes and Prostaglandins
• Satiety
• Flavor and mouth feel

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• Three Classes of Lipids
• Triglycerides
• Phospholipids
• Sterols

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Triglycerides

• Most commonly found form of fats, oils, body
• Glycerol backbone

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Triglycerides
H O H--C--O--C--
O H--C--O--C-- O H--C--O--C--
H
Fatty Acid Fatty Acid Fatty Acid
H O H--C--O--C--
O H--C--O--C-- O H--C--O--C--
H
Fatty Acid

Fatty Acid
Fatty Acid
(Ester
bond) Glycerol 3 FAs
Triglyceride 3 H20
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Functions of Phospholipids(Fig. 5-2 lecithin)

• Makes up cell membrane
• Emulsifier

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Sterols

• A multi-ringed structure
• Does not have a glycerol backbone
• Does not readily dissolve in water

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Cholesterol is a Sterol (Fig. 5-2)

• Fig. 5-2 cholesterol

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Function of Cholesterol

• Essential component of cell membrane
• Produced by the liver
• Found only in animal products
• Forms important hormones
• Precursor to bile acids
• Incr. Cholesterol incr bile gall stones

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Dietary intake of Cholesterol lt300
mg/daySerum Cholesterol 200mg/dclHigh
Cholesterol gt240mg/dcl
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Fatty Acid Structure (Fig. 5-1-A)
H H H H H H H H H H H H H H
H H H O H-C--C--C--C--C--C--C--C--C--C--C--C--C
--C--C--C--C--C-OH H H H H H H H H
H H H H H H H H H
omega end alpha end
degree of saturation
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Three Ways to Identify Fats
Length of Chain Degree of Saturation Omega
Number
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Saturated Fatty Acid Structure (Fig. 5-1-A)
H H H H H H H H H H H H H H
H H H O H-C--C--C--C--C--C--C--C--C--C--C--C--C
--C--C--C--C--C-OH H H H H H H H H
H H H H H H H H H
omega end alpha end degree of
saturation single carbon bond
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Monounsaturated Fatty Acid Structure (Fig. 5-1-B)
H H H H H H H H H H H
H H H H O H-C--C--C--C--C--C--C--C--CC--C--C
--C--C--C--C--C--C-OH H H H H H H H
H H H H H H H H H H
omega end alpha end
One double bond
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Polyunsaturated Fatty Acid Structure (Fig. 5-1-C)
H H H H H H H H
H H H H H O H-C--C--C--C--C--CC--C--CC--C
--C--C--C--C--C--C--C-OH H H H H H H
H H H H H H H H H H H
omega end alpha end gt 2
double bonds
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Omega Number Linolenic Acid Omega 3
FA Linoleic Acid Omega 6 FA
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Essential Fatty Acids

• Body cant make it
• Needed for immune function, vision, cell
  membrane, and production of hormone-like compounds

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Essential Fatty Acid- Omega-3 (alpha-linolenic
acid)
H H H H H H H H H H H H H H
H H H O H-C--C--CC--C--C C--C--CC--C--C--C--C
--C--C--C--C-OH H H H
H H H H H H H H
omega end alpha end 1st double bond
is located on the 3rd carbon from the omega end
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Omega-3 Fatty Acid

• Primarily from fish oil
• Also found in canola or soybean oil (MUS)
• Eicosapentaenoic acid (EPA) and docosahexaenoic
  acid (DHA) are related
• Metabolized to form eicosanoids
• Recommended to eat fish 2 x per week
• Decreases blood clot formation
• Lowers risk of heart disease

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Essential Fatty Acid- Omega-6 (alpha-linoleic
acid)
H H H H H H H H
H H H H H O H-C--C--C--C-- C--C
C--C--CC--C--C--C--C--C--C--C--C-OH H H
H H H H H H H H H H H H H H H
omega end alpha end 1st double bond
is located on the 6th carbon from the omega end
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Omega-6 Fatty Acid

• Found in vegetable oils
• Only need 1 tablespoon a day
• Increase blood clot
• Increase inflammatory responses

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Comparison of Dietary Fats(Fig. 5-4)

• Fig. 5-4

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Oil kcal Fat MUS PUS Sat P/S Rating SAT _______
__________________________________________________
___ Butter 102 11.5 3.3 0.4 7.2 0.06
63 Palm oil 120 13.6 5.0 1.3
6.7 0.19 Coconut 117 13.6 0.8 0.2 11.8 0.02
87 Corn oil 1 20 13.6 3.3 8.0
1.7 4.71 Canola 124 14.0 8.2 4.1
1.0 4.10 Marg. TUB 102 12.0 3.0 6.0 3.0 2.0
25 Olive Oil 119 14.0 10 1.0 2.0 0.5
14 ______________________________________________
_____________ Per tablespoon
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Hydrogenation of fatty acids (Fig. 5-9)
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Hydrogenation

• Process used to solidify an oil
• Addition of H to CC double bonds
• Formation of trans fatty acid

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Rancidity

• Decomposed oils
• Breakdown of the CC double bonds by ultraviolet
  rays, O2
• Yields unpleasant odor and flavor
• PUFA more susceptible
• Limits shelf life

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Prevention of Rancidity

• Hydrogenation
• Addition of vitamin E
• Addition of Butylated hydroxyanisol (BHA) and
  Butylated hydroxytolune (BHT)
• Synthetic antioxidants that prevent rancidity

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Cis and Trans Fatty Acid (Fig.5-10)
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Health Dangers of Excessive Trans Fatty Acid

• Raises LDL
• Lowers HDL
• Increases risk for heart disease

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Minimize Intake of Trans Fatty Acid

• Limit use of hydrogenated fats
• Limit deep-fried foods
• Limit high fat baked goods
• Limit use of non-dairy creamers

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American Heart Associations Recommendations

• No RDA for fat but lt 30 of total energy intake
  (TEI) from all fats
• Eliminate smoking
• 8 -10 of TEI from saturated fat
• lt 10 of TEI from PUFA
• lt 15 of TEI from MUFA
• lt 300 mg dietary cholesterol/day
• lt 2400 mg sodium/day
• These guidelines are not recommended for children
  under 2 years of age

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Heart Disease

• Symptoms take years to develop
• Plaque build-up can begin in childhood
• Myocardial infarction (heart attack)
• Stroke

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Atherosclerosis--Hardening of the Arteries (Fig.
5-12)

• (Fig. 5-12)

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Transportation of Fat in the Bloodstream

• Water (blood) and oil (fat) are incompatible
• Unique system of fat transportation is needed

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Lipoprotein

• Chylomicrons
• Fat absorbed from small ilntestine transported
  dietary fat
• VLDL
• Way to transport lipids made by the liver broken
  down into LDL
• LDL
• carries cholesterol to tissues Clogs arteries
• HDL
• helps remove cholesterol prevents blockage

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High Density Lipoprotein (HDL)

• Synthesized by liver and intestine
• High proportion of protein
• Pick up cholesterol from dying cells and other
  sources
• Transfer cholesterol to other lipoprotein for
  transport to the liver for excretion
• HDL can also transfer directly back to the liver

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Benefits of (a high) HDL (level)

• Remove cholesterol from the blood stream
• HDL may block oxidation of LDL
• Reduce risk of heart disease
• Pre-menopausal women have higher HDL
• HDL should be gt35 post menopausal should have
  HDLgt45

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Low Density Lipoprotein

• Carries fat in blood stream allowing it to be
  deposited on arterial walls

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Signs of a Heart Attack

• Intense, prolong chest pain
• Shortness of breath
• Sweating
• Nausea and vomiting
• Dizziness
• Weakness
• Jaw, neck, shoulder pain
• Irregular heartbeat

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Reducing Your Risks--Primary Prevention

• Reduce dietary saturated fat and cholesterol
• Increase MUFA and PUFA to recommended amounts
• Increase dietary fiber
• Increase activity develop a exercise routine 20
  minutes 3 X week in THR!
• Adequate caloric intake to maintain healthy weight

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Lowering LDLs

• See your doctor to assess for other conditions
• Reduce dietary saturated fat and cholesterol
• Increase MUFA and PUFA
• Increase dietary fiber (soluble)

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Lowering Blood TG

• Is the most diet-responsive blood lipid
• Overeating
• Limit alcohol (hard)
• Limit simple sugars
• Small frequent meals
• Include fish in the diet

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Raise the HDL

• Physical activity
• IDEAL at least 45 min./day, 4 days a week
• Avoid smoking
• Eat regularly
• Eat less total fat
• Moderate (?) intake of alcohol increases HDL

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Food kcal fat SAT (gm) sf
Red Lobster Admiral's Feast 2000 97 48 49
(Coronary from the sea) Long John Silver's Fish
and 1270 58 27 46 BK Fish Sandwich 830
31 8 25 KFC Chicken Pot Pie
830 31 17 55 KFC Original Dinner 1160 52 19 36
Boston Market Pot Pie 750 25 11 44
McDonalds Large FF 470 19 8 42
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1.      Limit the consumption of baked goods  
Product total fat artery clogging SAT
Pillsbury Grands Buttermilk Biscuit 11 gm 7
gm KFC Biscuit 11 7 Starbucks
Cholesterol-free Scone 15 7 Dunkin
Donut 19 10 _________________________________
_________________________________
 
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Type kcal Fat (gm) Sat (gm)
Regular (16 fat) 143 7 5 Ice milk
93 3 2 Sherbet 137 2 1 Ben Jerry
(vanilla) 230 17 10 BJ (Chunky
Monkey) 280 18 10 Haagen-Dazs
(vanilla) 270 18 11 H-D (butter pecan)
320 24 11 Healthy Choice 100 2 1 DQ
soft serve 133 7 5 Baskin Robbins  (butter
pecan) 230 17 10 Fruit Bar 77 0 0 Dove
Bar 330 24 14 H-D Chocolate Bar 400 27 18 H-D
Ice cream sandwich 260 13
8 Popsicle 50 0 0 Creamsicle 110 3
2 Colombo Vanilla Yogurt (8 oz) 220 3
2 Colombo Fat Free 220 0 0 Ben Jerry
Frozen Yogurt (½ c) 170 3 2 B J Frozen FF
Yogurt 150 0 0
Colombo Frozen FF Yogurt 110 0 0
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Fat Free Does Not Mean All You Can Eat

• When fat is removed, sugar is usually put in its
  place
• Same or higher kcal level as non-fat-free foods
• Choose wisely

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Fat Substitutes

• Water (diet margarine)
• Simplesse egg white, frozen foods
• Fiber cellulose (Oatrim)
• Olestra (links fatty acid to sucrose)
• not digested
• fat-soluble vitamins issue