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Lecture Discovering nutrition - Chapter 5: Lipids, not just fat

After studying this chapter you will be able to understand: What are lipids? fatty acids are key building blocks, triglycerides, phospholipids, sterols, lipid digestion and absorption, transportation of lipids in the body, recommendations for fat intake, lipids and health. | Chapter 5 Lipids: Not Just Fat What Are Lipids? Essential nutrients Provide energy Help transport fat-soluble nutrients throughout the body Contribute greatly to the flavor and texture of food Lipids Include Triglycerides (most abundant lipids) In body: stored in adipose tissue In food: “fats and oils” Phospholipids (~2% of dietary lipids) Plant and animal origin Body can make them Soluble in fat and water Sterols (very, very small % of lipids) Most well known: Cholesterol 3 Fatty Acids Are Key Building Blocks Fatty acid Determines whether a fat is solid or liquid at room temperature Basic structure: (-COOH); (-CH3) Fatty Acids Are Key Building Blocks Chain length Fatty acids differ in chain length Lengths vary from 4 to 24 carbons Grouped as short-chain, medium-chain, and long-chain Fatty Acids Are Key Building Blocks Chain Length Shorter fatty acids remain liquid at room temperature and even with refrigeration Shorter fatty acids also are more water-soluble Fatty Acids Are Key Building Blocks Saturation Saturated fatty acids All single bonds between carbons Unsaturated fatty acids One or more carbon bonds is a double bond Monounsaturated fatty acid (MUFA) Polyunsaturated fatty acid (PUFA) Fats with more double bonds are generally more liquidy Fatty Acids Are Key Building Blocks Cis vs. trans Unsaturated fatty acids can vary in shape Cis fatty acids Chain is bent Occur naturally Trans fatty acids Chain is straighter Produced by hydrogenation Hydrogenation: Adds H to unsaturated FA 10 Trans Fat In health, trans fatty acids are known to raise LDL (“bad”) cholesterol, and lower HDL (“good cholesterol”), promote systemic inflammation, and increase triglycerides in your blood. History and how it is made: In Europe (1910): needed a cheaper butter substitute for soldiers In US (1960s): People wanted to eat a “healthier and cheaper butter” food scientists decided to hydrogenate vegetable oil to solidify them Process: steam remove impurities as well as vitamins and | Chapter 5 Lipids: Not Just Fat What Are Lipids? Essential nutrients Provide energy Help transport fat-soluble nutrients throughout the body Contribute greatly to the flavor and texture of food Lipids Include Triglycerides (most abundant lipids) In body: stored in adipose tissue In food: “fats and oils” Phospholipids (~2% of dietary lipids) Plant and animal origin Body can make them Soluble in fat and water Sterols (very, very small % of lipids) Most well known: Cholesterol 3 Fatty Acids Are Key Building Blocks Fatty acid Determines whether a fat is solid or liquid at room temperature Basic structure: (-COOH); (-CH3) Fatty Acids Are Key Building Blocks Chain length Fatty acids differ in chain length Lengths vary from 4 to 24 carbons Grouped as short-chain, medium-chain, and long-chain Fatty Acids Are Key Building Blocks Chain Length Shorter fatty acids remain liquid at room temperature and even with refrigeration Shorter fatty acids also are more water-soluble Fatty Acids Are Key .