CHAPTER 5 LIPIDS: THE CONDENSED ENERGY Copyright © 2010, 2005, 1998 by Saunders, an imprint of...

CHAPTER 5CHAPTER 5

LIPIDS: THE CONDENSED LIPIDS: THE CONDENSED ENERGYENERGY

Copyright © 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.

Copyright © 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.Copyright © 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 2

Lipids: The Condensed EnergyLipids: The Condensed Energy

In 2006, added fats and In 2006, added fats and oils provided more oils provided more calories/day for the calories/day for the average American than average American than any other food groupany other food group

NHANES data find that NHANES data find that only 17%only 17%––20% of 20% of population meets the population meets the guidelines of <30% of guidelines of <30% of calories from fatcalories from fat


Classification of FatsClassification of Fats

Simple lipids can be Simple lipids can be found in foods and in the found in foods and in the bodybodyTriglyceridesTriglyceridesFatty acidsFatty acids

Structural lipids are Structural lipids are produced by the bodyproduced by the bodyLipoproteinsLipoproteinsPhospholipidsPhospholipids

From Thibodeau GA, Patton KT: Anatomy & Physiology, ed From Thibodeau GA, Patton KT: Anatomy & Physiology, ed 6. St. Louis, Mosby, 2007.6. St. Louis, Mosby, 2007.


Classification of Fats: Classification of Fats: Simple LipidsSimple Lipids

Simple lipidsSimple lipidsSaturated fatty acids (SFAs)Saturated fatty acids (SFAs)

Primarily in animal products (meat and dairy)Primarily in animal products (meat and dairy) Implicated in causing Implicated in causing in total and LDL in total and LDL

cholesterol causing an cholesterol causing an risk for CVD risk for CVD

Monounsaturated fatty acids (MUFAs)Monounsaturated fatty acids (MUFAs) Primarily in plant foods (olive oil, canola oil, Primarily in plant foods (olive oil, canola oil,

peanuts, pecans, almonds, avocados)peanuts, pecans, almonds, avocados) HDL cholesterol, which has a protective HDL cholesterol, which has a protective

effect for CVDeffect for CVD

Barbara Cousins. In Thibodeau GA, Patton Barbara Cousins. In Thibodeau GA, Patton KT (eds): Anatomy & Physiology, ed 6. St. KT (eds): Anatomy & Physiology, ed 6. St.

Louis: Mosby, 2007.Louis: Mosby, 2007.



TransTrans fatty acid fatty acid Found in meats, dairy, stick margarine, Found in meats, dairy, stick margarine,

shortening, salty snacks, high-fat baked shortening, salty snacks, high-fat baked goods, commercial frying fatsgoods, commercial frying fats

High intakes result in elevated total and High intakes result in elevated total and LDL cholesterolLDL cholesterol

Effective January 1, 2006, FDA required Effective January 1, 2006, FDA required food labels to declare the amounts of food labels to declare the amounts of transtrans fat on nutrition labels fat on nutrition labels



Polyunsaturated fatty acids (PUFAs)Polyunsaturated fatty acids (PUFAs)Essential fatty acids (EFAs)Essential fatty acids (EFAs)Linoleic acid (omega-6 FA)—coldwater marine Linoleic acid (omega-6 FA)—coldwater marine

fish, soybean and canola oils, leafy vegetablesfish, soybean and canola oils, leafy vegetables Involved in development and function of retina and Involved in development and function of retina and

cerebral cortexcerebral cortex HDL is protective for CVDHDL is protective for CVD

Linolenic acid (omega-3 FA)—vegetable oils Linolenic acid (omega-3 FA)—vegetable oils like corn, safflower, soybean, sunflowerlike corn, safflower, soybean, sunflower Functions in growth, reproduction, and maintenance of Functions in growth, reproduction, and maintenance of

skin integrityskin integrity May May risk of CVD risk of CVD

Barbara Cousins. In Thibodeau GA, Patton KT (eds): Anatomy & Physiology, ed 6. St. Louis: Mosby, 2007.


Classification of Fats: Classification of Fats: Compound LipidsCompound Lipids

Phospholipids make up 40% of cell membrane Phospholipids make up 40% of cell membrane (e.g., enamel and dentin)(e.g., enamel and dentin)Synthesized in the body or obtained from the dietSynthesized in the body or obtained from the diet

Lipoproteins transport insolubleLipoproteins transport insolublefats in the bloodfats in the bloodHigh-density lipoproteins (HDLs)High-density lipoproteins (HDLs)Low-density lipoproteins (LDLs)Low-density lipoproteins (LDLs)Very low-density lipoproteins (VLDLs)Very low-density lipoproteins (VLDLs)ChylomicronsChylomicrons

CholesterolCholesterolPrecursor for hormones and structuralPrecursor for hormones and structural

componentcomponentFrom Thibodeau GA, Patton KT: Anatomy & From Thibodeau GA, Patton KT: Anatomy &

Physiology, ed 6. St. Louis: Mosby, 2007.Physiology, ed 6. St. Louis: Mosby, 2007.


Physiological RolesPhysiological Roles

Concentrated source of energyConcentrated source of energySpares proteinSpares proteinSatiety valueSatiety valuePalatabilityPalatabilityAids absorption of fat-soluble vitaminsAids absorption of fat-soluble vitaminsProvides EFAsProvides EFAsAdipose tissue serves as an energy reserveAdipose tissue serves as an energy reserveCushions vital organsCushions vital organsProvides insulation and maintains body temperatureProvides insulation and maintains body temperature


Dietary Fats and Dental HealthDietary Fats and Dental HealthDecreased incidence of caries through the Decreased incidence of caries through the

following:following:Inhibits streptococcal growthInhibits streptococcal growthMay reduce dissolution of hydroxyapatite by acidsMay reduce dissolution of hydroxyapatite by acidsFat may act as a protective layer and prevent Fat may act as a protective layer and prevent

adherence of retentive CHOs or enhance clearanceadherence of retentive CHOs or enhance clearanceMay delay gastric emptying, enhancingMay delay gastric emptying, enhancing

fluoride absorptionfluoride absorption

From Darby ML, Walsh MM: Dental From Darby ML, Walsh MM: Dental Hygiene: Theory and Practice, ed 2. St. Hygiene: Theory and Practice, ed 2. St.

Louis: Saunders, 2003.Louis: Saunders, 2003.


Dietary Fats and Dental HealthDietary Fats and Dental Health

Periodontal diseasePeriodontal diseaseStudies using 3000 mg of n-6 PUFA and n-3 Studies using 3000 mg of n-6 PUFA and n-3

PUFAPUFAn-6 PUFAn-6 PUFA

gingival inflammation (significant atgingival inflammation (significant at

pp <0.016 level) <0.016 level) in levels of prostaglandins, arachidonic acid, in levels of prostaglandins, arachidonic acid,

and leukotrienesand leukotrienes

in pocket depth with n-3 (fish oil) and n-6 in pocket depth with n-3 (fish oil) and n-6 (borage oil)(borage oil)


Dietary RequirementsDietary Requirements

AMDR for total fat 20%-35% of AMDR for total fat 20%-35% of energy intakeenergy intakeKeep intake of saturated fat, Keep intake of saturated fat, transtrans

fat, and dietary cholesterol as low as fat, and dietary cholesterol as low as possible while still consuming a possible while still consuming a nutritionally adequate dietnutritionally adequate diet

AI for alpha-linolenic acid = 1.1 to AI for alpha-linolenic acid = 1.1 to 1.6 g/day1.6 g/day

AI for linoleic acid = 12-17 g/dayAI for linoleic acid = 12-17 g/day


SourcesSources

Principal sources of fat in US Principal sources of fat in US dietdietFats and oilsFats and oilsRed meats, poultry, and fishRed meats, poultry, and fishDairy products Dairy products

Combined they account for Combined they account for about 90% of total fat intakeabout 90% of total fat intake


Overconsumption andOverconsumption and Health-Related Problems Health-Related Problems

Obesity Obesity Excessive fat stores is a common disorderExcessive fat stores is a common disorder

Blood lipid levels (hyperlipidemia)Blood lipid levels (hyperlipidemia)Strongest dietary determinant of the blood Strongest dietary determinant of the blood

cholesterol level is dietary saturated fat cholesterol level is dietary saturated fat TransTrans fats increase risk of CVD 2- to 10-fold fats increase risk of CVD 2- to 10-fold

CancerCancerPossible link to high-fat diet, but research continuesPossible link to high-fat diet, but research continues


Underconsumption and Underconsumption and Health-Related ProblemsHealth-Related Problems

EFA deficiencyEFA deficiencySymptoms include dry, scaly, skin, hair loss, impaired Symptoms include dry, scaly, skin, hair loss, impaired

wound healing, visual impairment and impaired wound healing, visual impairment and impaired reproductive abilityreproductive ability

People at riskPeople at risk People w/fatty malabsorption syndromesPeople w/fatty malabsorption syndromes

(e.g., cystic fibrosis)(e.g., cystic fibrosis) Premature babiesPremature babies Very low-fat diets (<10% of calories from fat)Very low-fat diets (<10% of calories from fat)


Fat ReplacersFat ReplacersMethod to reduce fat intakeMethod to reduce fat intake

National survey found 88% of US population National survey found 88% of US population consumes low-fat, reduced-fat, or fat-free foods consumes low-fat, reduced-fat, or fat-free foods and beveragesand beverages

Types of fat replacersTypes of fat replacersFat “substitutes” or “analogs”Fat “substitutes” or “analogs”

Contain less energy than fatContain less energy than fat““Fat mimetics”Fat mimetics”

Mimic properties of fatMimic properties of fatFat “barriers”Fat “barriers”

Reduce absorption of fats during fryingReduce absorption of fats during frying


Fat Replacers: ClassificationsFat Replacers: ClassificationsCarbohydratedCarbohydrated

Plant polysaccharides; include cellulose, gums, Plant polysaccharides; include cellulose, gums, dextrins, fiber, maltodextrins, starches, and dextrins, fiber, maltodextrins, starches, and polydextrosepolydextrose Thicken and add bulk, thereby producing a mouth feel similar Thicken and add bulk, thereby producing a mouth feel similar

to fatto fat Provide from 1 to 4 kcal/g Provide from 1 to 4 kcal/g Withstand heat used in fryingWithstand heat used in frying


Fat Replacers: ClassificationsFat Replacers: ClassificationsProtein-basedProtein-based

Form gels that provide structure and functionality Form gels that provide structure and functionality similar to that of fatsimilar to that of fat

Can’t be used at high temperatures—the protein Can’t be used at high temperatures—the protein coagulatescoagulates

Provide 1.3 to 4 kcal/g and have biological value of Provide 1.3 to 4 kcal/g and have biological value of the component amino acidsthe component amino acids

Example: Simplesse made from whey (milk protein) Example: Simplesse made from whey (milk protein) and egg whiteand egg white


Fat Replacers: ClassificationsFat Replacers: Classifications

Fat-basedFat-based Sucrose polyester olestra (Olean)Sucrose polyester olestra (Olean)

Fatty acids to nontraditional backbones (e.g., sugar) so Fatty acids to nontraditional backbones (e.g., sugar) so enzymes in gut are not able to cleave the fatty acidsenzymes in gut are not able to cleave the fatty acids

Heat-stable and retain their functional properties in baked and Heat-stable and retain their functional properties in baked and fried foodsfried foods

Pose a risk for GI distress (intestinal discomfort, cramps, and Pose a risk for GI distress (intestinal discomfort, cramps, and diarrhea) and reduce absorption of fat-soluble nutrients diarrhea) and reduce absorption of fat-soluble nutrients


Nutrition ConsiderationsNutrition Considerations

Wise choices of dietary fatsWise choices of dietary fatsWhen selecting and preparing meat, poultry, dry When selecting and preparing meat, poultry, dry

beans, and milk or milk products, choose lean, low-fat, beans, and milk or milk products, choose lean, low-fat, or fat-free or fat-free

Limit intake of fats and oils high in saturated and/or Limit intake of fats and oils high in saturated and/or trans trans fatty acids; choose products low in thesefatty acids; choose products low in these

If solid fat is added in cooking this countsIf solid fat is added in cooking this counts

as part of discretionary calorie allowanceas part of discretionary calorie allowanceSelect fish rich in omega-3 fatty acids,Select fish rich in omega-3 fatty acids,

such as salmon, trout, and herringsuch as salmon, trout, and herring

CHAPTER 5 LIPIDS: THE CONDENSED ENERGY Copyright © 2010, 2005, 1998 by Saunders, an imprint of...

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