Chapter 5Chapter 5
The Lipids: Fats, Oils, The Lipids: Fats, Oils, Phospholipids, and SterolsPhospholipids, and Sterols
Nutrition: Concepts & Controversies, 12e Nutrition: Concepts & Controversies, 12e Sizer/WhitneySizer/Whitney
Learning ObjectivesLearning Objectives
Describe how and where dietary lipids are broken down and absorbed during digestion and how they are transported throughout the body.
Describe the significance of the blood tests for HDL and LDL cholesterol.
Describe the roles of omega-3 and omega-6 fatty acids in the body, and discuss which may be too low in some people’s diets and how they can increase their intakes.
Learning ObjectivesLearning Objectives
Develop a diet plan that provides enough of the right kinds of fats within calorie limits.
Discuss evidence for the benefits and drawbacks of specific dietary fats in terms of their potential effects on human health.
Introduction Introduction
Diet moderate in fats Lipids are necessary and valuable Lipids can harm health
Three classes of lipids Triglycerides Phospholipids Sterols
Usefulness of Fats in the BodyUsefulness of Fats in the Body
Chief storage form of energy Provides most energy for body’s work
Adipose tissue Secretes hormones
Purposes of fat Shock absorbers, insulation, cell
membranes Fat-soluble substances
A Fat CellA Fat Cell
Triglycerides: Fatty Acids and Triglycerides: Fatty Acids and GlycerolGlycerol
Triglycerides Glycerol backbone Three fatty acids
Fatty acid differences Chain length Saturation
Animal species make triglycerides
Saturated Versus Unsaturated Saturated Versus Unsaturated Fatty AcidsFatty Acids
Saturation Hydrogen atoms
Levels of saturation Saturated Unsaturated
PolyunsaturatedMonounsaturated
Three Types of Fatty AcidsThree Types of Fatty Acids
Phospholipids and SterolsPhospholipids and Sterols
Phospholipids Glycerol, two fatty acids, and a phosphorus
moleculeSoluble in water and fat
Emulsifier Sterols
Roles in the body Plant sterols
Digestion and Absorption of FatsDigestion and Absorption of Fats
Digestion Stomach Small intestine
Bile Pancreas
The Process of Lipid Digestion The Process of Lipid Digestion and Absorptionand Absorption
Storing and Using the Body’s FatStoring and Using the Body’s Fat
Body conserves fat molecules Fat depots Excess carbohydrate
Call for energy Dismantle stored triglycerides
Release fatty acids into blood Carbohydrate’s role
How to use more fat for energy…
Dietary Fat, Cholesterol, and Dietary Fat, Cholesterol, and HealthHealth
Heart and artery disease Saturated and trans fats Beneficial fats
Cancer Diet high in saturated fats
Obesity Overconsumption of calories
Lipoproteins and Heart Disease Lipoproteins and Heart Disease RiskRisk
Lipoprotein movement in the body Liver
Types of lipoproteins Chylomicrons Very-low-density lipoproteins (VLDL) Low-density lipoproteins (LDL) High-density lipoproteins (HDL)
LipoproteinsLipoproteins
Lipoproteins and Heart Disease Lipoproteins and Heart Disease RiskRisk
LDL and HDL difference Size and density Delivery and
scavenging Inflammation Heart attack risk
Oxidation of LDL Phytochemicals
Food Fat, Saturated Fat, and Food Fat, Saturated Fat, and CaloriesCalories
Top Contributors of Saturated Top Contributors of Saturated Fats to the U.S. DietFats to the U.S. Diet
The Need for Essential Fatty The Need for Essential Fatty AcidsAcids
Essential fatty acids Linoleic acid and
linolenic acid Functions
Eicosanoids
DRI recommendations Deficiencies
Omega-6 and Omega-3 Fatty Omega-6 and Omega-3 Fatty Acid FamiliesAcid Families
Linoleic Omega-6 fatty acid Arachidonic acid
Linolenic acid Omega-3 fatty acid DHA and EPA
Heart diseaseBrain function and vision Inflammation
Fish Oil Intakes and Fish Oil Intakes and Cardiovascular Death Rates Cardiovascular Death Rates
Recommendations for Omega-3 Recommendations for Omega-3 Fatty Acid IntakeFatty Acid Intake
Competition for metabolic enzymes Consumption levels
Lacking omega-3 fatty acids Fish oil supplements
Health concerns with fish oil supplements Omega-3 enriched foods Flaxseed
Mercury in Fish SpeciesMercury in Fish Species
Effects of Processing on Effects of Processing on Unsaturated FatsUnsaturated Fats
Hydrogenation Effects on fats
Oxidation of unsaturated oils Hydrogenation of oils
Benefits of hydrogenation Nutrient losses Alternatives to hydrogenation
Hydrogenation Yields Both Hydrogenation Yields Both Saturated and Trans-Fatty AcidsSaturated and Trans-Fatty Acids
Effects of Processing on Effects of Processing on Unsaturated FatsUnsaturated Fats
Trans-fatty acids Polyunsaturated fats
Change in chemical structure
Health effects LDL and HDL cholesterol Similarities with saturated fat
Trans fat in foods
Fat in the DietFat in the Diet
Meat, poultry, fish, dried peas & beans, eggs, & nuts Four categories for meat Limit intake to 5 to 7 ounces per day Choosing low-fat meats
Ground turkey or chicken vs. beef
Milk, yogurt, and cheese Foods not included in this category
Grains
Calories, Fat, and Saturated Fat Calories, Fat, and Saturated Fat in Cooked Ground Meat Pattiesin Cooked Ground Meat Patties
Lipids in Milk, Yogurt, and CheeseLipids in Milk, Yogurt, and Cheese
Lipids in Bread, Cereal, Rice, and Lipids in Bread, Cereal, Rice, and PastaPasta