1. The Skinny on Fats!! Nutrition 120

2. Why Do We NEED Fat?? ProtectionProtection InsulationInsulation EnergyEnergy Storage (Fat Soluble Vitamins)Storage (Fat Soluble Vitamins) FlavourFlavour Skin and HairSkin and Hair Build nerves and membranesBuild nerves and membranes

3. Fats – Things to Know! Scientists call fats lipidsScientists call fats lipids Fats are lipids if they are solid at room temperature.Fats are lipids if they are solid at room temperature. Lipids that are liquid at room temperature are called oils.Lipids that are liquid at room temperature are called oils. More than 90% of the fats in our foods are called triglycerides = glycerol + 3 fatty acidsMore than 90% of the fats in our foods are called triglycerides = glycerol + 3 fatty acids

4. More “FAT FACTS” 1 lb of fat = 3500 calories1 lb of fat = 3500 calories 30% of your diet should come from fat sources30% of your diet should come from fat sources No more than 10% of fat consumed should be saturated.No more than 10% of fat consumed should be saturated. http://www.myfatstranslator.com/http://www.myfatstranslator.com/http://www.myfatstranslator.com/

5. If WE need it – why is it such a problem?? OVERCONSUMPTION! & TYPEOVERCONSUMPTION! & TYPE

6. Fatty Acids Chains of carbon atoms with hydrogen atoms attached to the, plus an acid groupChains of carbon atoms with hydrogen atoms attached to the, plus an acid group Some fatty acid chains have only a few carbon atoms and others have 20 or moreSome fatty acid chains have only a few carbon atoms and others have 20 or more Short chains are liquid oilsShort chains are liquid oils Long chains are usually solid fats.Long chains are usually solid fats. Babies can digest short chain fatty acids easiest. Therefore, what type of fatty acid chains would be found in milk?Babies can digest short chain fatty acids easiest. Therefore, what type of fatty acid chains would be found in milk?

8. Common Fatty Acids The most common fatty acids in food contain 18 carbon atoms :The most common fatty acids in food contain 18 carbon atoms : 1.Oleic acid – found in olive oil and other plant and animal lipids 2.Stearic acid – main fatty acid in beef 3.Linoleic and linolenic – sometimes called essential fatty acids b/c our bodies cannot make them – we need to get them from foods.

10. 3 Types of Fatty Acids: 1.Saturated 2.Monounsaturated 3.Polyunsaturated The difference is the degree of saturation on hydrogen atoms!The difference is the degree of saturation on hydrogen atoms! Complete Assignment 1 – Textbook Questions on page 91.Complete Assignment 1 – Textbook Questions on page 91.

11. Monday: Look at handout from Friday’s Class:Look at handout from Friday’s Class: MENU SPEAK MENU SPEAK

12. Saturated Saturated fatty acids are full – the carbon atoms in the chain are holding all the hydrogens they can.Saturated fatty acids are full – the carbon atoms in the chain are holding all the hydrogens they can. Has only single bonds throughout chain – these bonds are strong and hard to breakHas only single bonds throughout chain – these bonds are strong and hard to break Mostly found in animal products such as cheese and meat (Exception **Coconut/Palm Oils)Mostly found in animal products such as cheese and meat (Exception **Coconut/Palm Oils) Much less healthy than poly or monounsaturated sources (a diet high in these can lead to heart disease)Much less healthy than poly or monounsaturated sources (a diet high in these can lead to heart disease)

14. Unsaturated Fatty Acids Have at least one double bondHave at least one double bond There are 3 types: monounsaturated and polyunsaturated (good forms)There are 3 types: monounsaturated and polyunsaturated (good forms) Trans unsaturated (VERY bad form)Trans unsaturated (VERY bad form)

15. Monounsaturated Fatty Acids Contains only one double bond – resulting in fewer hydrogen moleculesContains only one double bond – resulting in fewer hydrogen molecules Common in plant fatsCommon in plant fats Examples are olive and peanut oilExamples are olive and peanut oil These fats are liquid at room temperatureThese fats are liquid at room temperature

17. Polyunsaturated Fatty Acids Contains two or more double bonds – resulting in even fewer hydrogen moleculesContains two or more double bonds – resulting in even fewer hydrogen molecules Common in plant fatsCommon in plant fats Examples are: corn, safflower, and soybeanExamples are: corn, safflower, and soybean These fats are liquid at room temperatureThese fats are liquid at room temperature They become rancid quicklyThey become rancid quickly The majority of our fat intake should come from unsaturated sources – the more hydrogen’s missing, the better the choice!!The majority of our fat intake should come from unsaturated sources – the more hydrogen’s missing, the better the choice!!

19. The “UGLY” TRANS unsaturated FATTY ACIDS Trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. Another name for trans fats is “partially hydrogenated oils." Trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. Another name for trans fats is “partially hydrogenated oils." Companies use them because they are inexpensive to produce and last a long time (also give food a desirable taste and texture)Companies use them because they are inexpensive to produce and last a long time (also give food a desirable taste and texture) Trans fats raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels. Trans fats raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels.

20. Summary The GOOD….The GOOD…. The BAD….The BAD…. The UGLY….The UGLY….

21. THE GOOD

22. THE BAD

23. THE UGLY

24. 3 Classes of Lipids 1.Triglycerides – fat found in foods and body (3 fatty acids + glycerol) Ex: polyunsaturated, monounsaturated and saturated fats 2.Phospholipids – contain phosphorus Ex. Lecithin (made by the liver and found in foods such as egg yolks; it is also an emulsifier; part of cell membranes)

25. 3 Classes of Lipids cont…. 3.Sterols – Complex molecule structure Ex: hormones, vitamin D, cholesterol *Cholesterol is a white, waxy lipid made by the body that is part of every cell ; make sex hormones and bile acids (Found only in animals) Your body makes it – so it is ___________

26. Lipid Digestion and Absorption Most fats in foods are TRIGLYCERIDES!! (glycerol + 3 FA)Most fats in foods are TRIGLYCERIDES!! (glycerol + 3 FA) In the stomach fats float to the top of carbs/proteinsIn the stomach fats float to the top of carbs/proteins In the SI, they mix with bile (emulsifier) into dropletsIn the SI, they mix with bile (emulsifier) into droplets Pancreatic enzymes break triglycerides down into single glycerol, fatty acids called monoglycerides.Pancreatic enzymes break triglycerides down into single glycerol, fatty acids called monoglycerides. Absorption takes place in the SIAbsorption takes place in the SI

27. Lipid Digestion & Absorption Lipids travel in the blood to tissues throughout the body.Lipids travel in the blood to tissues throughout the body. Glycerol and short-chain FA’s pass through the intestinal lining directly into the bloodstream Glycerol and short-chain FA’s pass through the intestinal lining directly into the bloodstream Monoglycerides and long chain FA’s are converted back into triglycerides. Monoglycerides and long chain FA’s are converted back into triglycerides. Balls of triglycerides are thinly coated with cholesterol, phospholipids, and proteins, forming chylomicrons.Balls of triglycerides are thinly coated with cholesterol, phospholipids, and proteins, forming chylomicrons.

28. Chylomicrons Type of lipoprotein that help transport fats in the body.Type of lipoprotein that help transport fats in the body. Carry absorbed dietary fat to body cells. They are absorbed into the lymphatic system and move into the blood stream.Carry absorbed dietary fat to body cells. They are absorbed into the lymphatic system and move into the blood stream. They are important in moving fat efficiently through your blood vessels to the tissues where they are needed.They are important in moving fat efficiently through your blood vessels to the tissues where they are needed.

29. More types of Lipoproteins: (things that transport fat in the body) VLDL – carry triglycerides and cholesterol made by the liver to body cells….some triglycerides get broken down and released, causing them to be more dense carrying extra cholesterol. (Bad cholesterol) VLDL – carry triglycerides and cholesterol made by the liver to body cells….some triglycerides get broken down and released, causing them to be more dense carrying extra cholesterol. (Bad cholesterol) LDL – carry cholesterol through the blood to body cells (bad cholesterol) LDL – carry cholesterol through the blood to body cells (bad cholesterol) HDL – pick up cholesterol in the blood and take it to the liver as waste. (good cholesterol)HDL – pick up cholesterol in the blood and take it to the liver as waste. (good cholesterol)

30. Small Intestine Triglycerides are broken down Lipids are absorbed Some are packaged as chylomicrons Liver – cholesterol and triglycerides are packaged into VLDL VLDL lose triglycerides and become LDL, which carry cholesterol and other lipids to body cells Body cells – break down fatty acids for energy or rebuild them into triglycerides for storage HDL carry cholesterol and other lipids from body cells back to liver to be processed as waste See handout

31. READ MY LIPIDS READ MY LIPIDS See PPT #2 Correct Homework