Transcript Chapter_06R
LIPIDS: THE CONDENSED
ENERGY
CHAPTER 6
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
Lipids: The Condensed Energy
In 2006, added fats and
oils provided more
calories/day for the
average American than
any other food group
NHANES data find that
only 17% to 20% of
population meets the
guidelines of <30% of
calories from fat
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Classification of Fats
Simple lipids can be
found in foods and in the
body
Triglycerides
Fatty acids
Structural lipids are
produced by the body
Lipoproteins
Phospholipids
From Patton KT, Thibodeau GA: Anatomy & Physiology, ed
8. St. Louis: Mosby, 2013.
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Classification of Fats:
Simple Lipids
Simple lipids
Saturated fatty acids (SFAs)
Primarily in animal products (meat and dairy)
Implicated in causing in total and LDL
cholesterol, causing an risk for CVD
Barbara Cousins. In Thibodeau GA, Patton
KT (eds): Anatomy & Physiology, ed 6. St.
Louis: Mosby, 2007.
Monounsaturated fatty acids (MUFAs)
Primarily in plant foods (olive oil, canola oil,
peanuts, pecans, almonds, avocados)
HDL cholesterol, which has a protective effect
for CVD
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Classification of Fats:
Simple Lipids
Trans fatty acid
Found in meats, dairy, stick margarine,
shortening, salty snacks, high-fat baked
goods, commercial frying fats
High intakes result in elevated total and
LDL cholesterol
FDA requires food labels to declare the
amounts of trans fat on nutrition labels
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Classification of Fats:
Simple Lipids
Polyunsaturated fatty acids (PUFAs)
Essential fatty acids (EFAs)
Linoleic acid (omega-6 FA)—coldwater marine
fish, soybean and canola oils, leafy vegetables
Involved in development and function of retina and
cerebral cortex
HDL is protective for CVD
Linolenic acid (omega-3 FA)—vegetable oils
like corn, safflower, soybean, sunflower
Barbara Cousins. In Patton KT, Thibodeau
GA: Anatomy & Physiology, ed 8. St. Louis:
Mosby, 2013.
Functions in growth, reproduction, and maintenance of
skin integrity
May risk of CVD
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Classification of Fats:
Compound Lipids
Phospholipids make up 40% of cell membrane
(e.g., enamel and dentin)
Synthesized in the body or obtained from the diet
Lipoproteins transport insoluble
fats in the blood
High-density lipoproteins (HDLs)
Low-density lipoproteins (LDLs)
Very-low-density lipoproteins (VLDLs)
Chylomicrons
Cholesterol
Precursor for hormones and structural
component
From Patton KT, Thibodeau GA: Anatomy &
Physiology, ed 8. St. Louis: Mosby, 2013.
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Physiological Roles
Concentrated source of energy
Spares protein
Satiety value
Palatability
Aids absorption of fat-soluble vitamins
Provides EFAs
Adipose tissue serves as an energy reserve
Cushions vital organs
Provides insulation and maintains body temperature
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Dietary Fats and Dental Health
Decreased incidence of caries through the
following:
Inhibits streptococcal growth
May reduce dissolution of hydroxyapatite by acids
Fat may act as a protective layer and prevent
adherence of retentive CHOs or enhance clearance
May delay gastric emptying, enhancing
fluoride absorption
From Darby ML, Walsh MM: Dental
Hygiene: Theory and Practice, ed 3. St.
Louis: Saunders, 2015.
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Dietary Fats and Dental Health
Periodontal disease
Studies using 3000 mg of n-6 PUFA and n-3
PUFA
n-6 PUFA
gingival inflammation (significant at
p <0.016 level)
in levels of prostaglandins, arachidonic acid,
and leukotrienes
in pocket depth with n-3 (fish oil) and n-6
(borage oil)
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Dietary Requirements
AMDR for total fat 20% to 35% of
energy intake
Keep intake of saturated fat, trans
fat, and dietary cholesterol as low as
possible while still consuming a
nutritionally adequate diet
AI for alpha-linolenic acid = 1.1 to
1.6 g/day
AI for linoleic acid = 12 to 17 g/day
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Sources
Principal sources of fat in US
diet
Fats and oils
Red meats, poultry, and fish
Dairy products
Combined these sources
account for about 90% of
total fat intake
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Overconsumption and
Health-Related Problems
Obesity
Excessive fat stores is a common disorder
Blood lipid levels (hyperlipidemia)
Strongest dietary determinant of the blood
cholesterol level is dietary saturated fat
Trans fats increase risk of CVD twofold to 10-fold
Cancer
Possible link to high-fat diet, but research continues
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Underconsumption and
Health-Related Problems
EFA deficiency
Symptoms include dry, scaly, skin; hair loss; impaired
wound healing; visual impairment; and impaired
reproductive ability
People at risk
People w/fatty malabsorption syndromes
(e.g., cystic fibrosis)
Premature babies
Very low-fat diets (<10% of calories from fat)
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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Fat Replacers
Method to reduce fat intake
National survey found 88% of US population
consumes low-fat, reduced-fat, or fat-free foods
and beverages
Types of fat replacers
Fat “substitutes” or “analogs”
Contain less energy than fat
“Fat mimetics”
Mimic properties of fat
Fat “barriers”
Reduce absorption of fats during frying
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Fat Replacers: Classifications
Carbohydrated~Plant polysaccharides
Protein-based~Simplesse
Fat-based~Olean
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Nutrition Considerations
Wise choices of dietary fats
When selecting and preparing meat, poultry, dry
beans, and milk or milk products, choose lean, low-fat,
or fat-free
Limit intake of fats and oils high in saturated and/or
trans fatty acids; choose products low in these
If solid fat is added in cooking, this counts
as part of discretionary calorie allowance
Select fish rich in omega-3 fatty acids,
such as salmon, trout, and herring
Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
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HEALTH APPLICATION
Hyperlipidemia
Discuss major health risks associated with
hyperlipidemia
Consider optimum levels of
LDL/HDL/triglycerides and patient actions for
achieving them
What dietary recommendations might a health
provider make for patient’s reduction of
hyperlidipemia?
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