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Chp 5 -Nutrition: Concepts & Controversies, 12e Sizer/Whitney
HUN 4296 Nutrition & Health Issues Week 2 Day 1 Part 3 The Lipids: Fats, Oils, Phospholipids, and Sterols Chp 5 -Nutrition: Concepts & Controversies, 12e Sizer/Whitney
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Introduction Diet moderate in fats Three classes of lipids
Lipids are necessary and valuable Lipids can harm health Three classes of lipids Triglycerides Phospholipids Sterols
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Usefulness 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
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A Fat Cell
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Usefulness of Fats in Food
People naturally like high-fat foods Aromas Flavors Tenderness Satiety
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Triglycerides: Fatty Acids and Glycerol
Glycerol backbone Three fatty acids Fatty acid differences Chain length Saturation Animal species make triglycerides
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Saturated Versus Unsaturated Fatty Acids
Saturation Hydrogen atoms Levels of saturation Saturated Unsaturated Polyunsaturated Monounsaturated
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Three Types of Fatty Acids
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Saturated Versus Unsaturated Fatty Acids
Melting point More unsaturated, more liquid Fat hardness Softer generally is healthier Sources of fatty acids Heart disease
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Fatty Acid Composition of Common Food Fats
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Phospholipids and Sterols
Glycerol, two fatty acids, and a phosphorus molecule Soluble in water and fat Emulsifier Sterols Roles in the body Plant sterols
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Digestion and Absorption of Fats
Stomach Small intestine Bile Pancreas
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Digestion and Absorption of Fats
Fatty acids split from glycerol Fatty acids, phospholipids, and monoglycerides Bile shuttles lipids across mucus layer Efficiency of absorption process Speed of digestion
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The Process of Lipid Digestion and Absorption
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Transport of Fats Glycerol and shorter-chain fatty acids Larger lipids
Bloodstream Larger lipids Protein carriers Released into lymph Chylomicrons
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Storing 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…
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Glucose to Fat
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Dietary Fat, Cholesterol, and Health
Heart and artery disease Saturated and trans fats Beneficial fats Cancer Diet high in saturated fats Obesity Overconsumption of calories
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Recommendations for Lipid Intakes
Some fat in the diet is essential Healthy range of fat intakes DRI 20 to 35 percent of daily energy Fats to keep low Essential fatty acids
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Lipoproteins and Heart Disease Risk
Lipoprotein movement in the body Liver Types of lipoproteins Chylomicrons Very-low-density lipoproteins (VLDL) Low-density lipoproteins (LDL) High-density lipoproteins (HDL)
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Lipoproteins
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Lipoproteins and Heart Disease Risk
LDL and HDL difference Size and density Delivery and scavenging Inflammation Heart attack risk Oxidation of LDL Phytochemicals
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Food Cholesterol and Blood Cholesterol
Saturated and trans fats CVD risk indicators Dietary cholesterol Genetic inheritance Moderation is key
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Recommendations Applied
Heart disease Leading cause of death among Americans Lower LDL Dietary tactics Trim saturated and trans fats from diet Raise HDL Physical activity Benefits for heart health
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Food Fat, Saturated Fat, and Calories
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Top Contributors of Saturated Fats to the U.S. Diet
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The Need for Essential Fatty Acids
Linoleic acid and linolenic acid Functions Eicosanoids DRI recommendations Deficiencies
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Omega-6 and Omega-3 Fatty Acid Families
Linoleic Omega-6 fatty acid Arachidonic acid Linolenic acid Omega-3 fatty acid DHA and EPA Heart disease Brain function and vision Inflammation
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Fish Oil Intakes and Cardiovascular Death Rates
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Recommendations for Omega-3 Fatty 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
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Food Sources of Omega-6 and Omega-3 Fatty Acids
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Seafood Safety – Balancing Risks and Benefits
Safe consumption levels Mercury Methylmercury Damage to the body Cooking methods of fish Benefits outweigh risks
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Mercury in Fish Species
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Effects of Processing on Unsaturated Fats
Hydrogenation Effects on fats Oxidation of unsaturated oils Hydrogenation of oils Benefits of hydrogenation Nutrient losses Alternatives to hydrogenation
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Hydrogenation Yields Both Saturated and Trans-Fatty Acids
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Effects of Processing on Unsaturated Fats
Trans-fatty acids Polyunsaturated fats Change in chemical structure Health effects LDL and HDL cholesterol Similarities with saturated fat Trans fat in foods
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Fat in the Diet Essential fat Visible vs. invisible fat Added fats
20% of calories from unsaturated fats Visible vs. invisible fat Added fats Majority are invisible fats
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Fat 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
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Calories, Fat, and Saturated Fat in Cooked Ground Meat Patties
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Lipids in Milk, Yogurt, and Cheese
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Lipids in Bread, Cereal, Rice, and Pasta
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Substitute Ingredients to Lower Saturated Fat Intakes
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Good Fats and Bad Fats – Which are Which?
Controversy 5
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Objectives to “Low-Fat” Guidelines
Problems with low-fat diets Groups who benefit from low-fat diets Mediterranean-type diets New guidelines Up to 35 percent of total calories
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High-Fat Foods and Heart Health
Olive oil Potential health benefits Darker the better (extra virgin) Canola oil
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High-Fat Foods and Heart Health
Mediterranean diet Whole foods Dietary focus Fish Nuts Walnuts Almonds Potential benefits
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High-Fat Foods and Heart Health
Butter or margarine Read labels Low saturated fat and trans fat levels Plant-enriched margarines Drawbacks Fats to avoid Choose carefully among high-fat foods
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Impact of Change in Saturated Fatty Acid Intake on Blood LDL Cholesterol and Heart Disease Risk
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