The Lipids: Fats & Oils
Chapter 5
A Primer on Fats
The functions of fats in the body
 The functions of fats in foods
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A Closer View of Fats
Saturated vs. unsaturated fats
 The essential fatty acids
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Linoleic acid & linolenic acid
Omega-6 vs. omega-3 fatty acids
Characteristics of Fats in Foods
Firmness/melting properties
 Preventing spoilage
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Hydrogenation
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Increases degree of saturation
Antioxidant additives
 Emulsifier additives
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The Other Members of the Lipid
Family: Phospholipids & Sterols
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Phospholipids
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Lecithin
Sterols
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Cholesterol
How the Body Handles Fat
Digestion
 Absorption
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Chylomicrons - type of lipoprotein
Lipoproteins
Low-density lipoproteins (LDL)
 High-density lipoproteins (HDL)
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“Good” vs. “Bad” Cholesterol

Atherosclerosis
Narrowing of arteries due to cholesterolcontaining plaque build-up
 Oxidized LDL-cholesterol (o-LDL)
 Foam cells
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LDL = bad
 HDL = good
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Fat in the Diet
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DGA: total fat - 20%-35% of calories
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Replace saturated fat with
monounsaturated
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Saturated fat - <10% of calories
But control total energy intake
Visible vs. invisible fat
Oh, Nuts! You Mean Fat Can Be
Healthy?
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When more fat might be better
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What’s so special about olive oil?
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Mediterranean diet = 30%-35% of calories
from fat
High in monounsaturated oleic acid
Something’s fishy here!
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Oily fish are high in omega-3 fats
Oh, Nuts! You Mean Fat Can Be
Healthy?
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Nuts to you!
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Omega-3 sources: soybeans, pecans,
walnuts, & flaxseed
What’s your meal mentality?

Slower-paced meals in pleasant
environment
The Trans Fatty Acid Controversy-Is Butter Better?
Trans fats raise LDL & lower HDL
 Hydrogenation results in trans fats
 Trans fats must be listed on food labels
as of January 2006
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“Trans fat free” = <0.5 g/serving
Butter is not better
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You should avoid sat. & trans fats
Understanding Fat Substitutes

Fat-reduction ingredients
Egg whites, nonfat milk
 Starches, gums, & gels
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Fat substitutes
Simplesse
 Olestra
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Choosing Fats Sensibly
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Use nonstick sprays  Prepare lean cuts of
meat & trim visible
 Reduce fat in recipes
fat
gradually
 Use herbs, spices, &
 Reduce oils used for
other seasonings
sautéing
 Use fruit jams or
 Refrigerate broths to
whipped spreads
skim off fat
Nourish the Heart
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Become a savvy supermarket shopper
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Read food labels
Nourish the Heart

Keep blood cholesterol at or below the
recommended levels
Replace saturated fats with
monounsaturated & polyunsaturated
 Replace sat. & trans fats with unsaturated
from healthful foods
 Add fiber
 Increase fruit & vegetable intake
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Nourish the Heart

Balance energy intake with energy
needs
Maintain healthy body weight
 Keep physically fit
 At least 30 minutes of moderate exercise
per day
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Diet & Heart Disease
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No one is free of atherosclerosis
Increases blood pressure
 Restricts blood flow
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Risk factors for atherosclerosis
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Modifiable vs. non-modifiable
High LDL/low HDL = strong correlation
with heart disease
Diet & Heart Disease
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To reduce total & LDL-cholesterol:
Reduce saturated & trans fat intakes
 Plant stanols or sterols
 Cholesterol: <300 mg/day
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HDL increased by:
Female gender
 Not smoking
 Regular exercise
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Diet & Heart Disease
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Homocysteine
Product of protein breakdown
 High levels linked to heart disease & strokes
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Moderate alcohol intake protective
 Garlic may be beneficial
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Evidence is conflicting