Fats.pdf

The Lipids Triglycerides, Phospholipids, and Sterols Dr. Khadija Hassan Objectives: Understand functions of fats. Recognize the types of fat. Identify the food sources of fats. Understand the daily requirement of fat. Discuss about cholesterol. Definition of Lipids Subst...

The Lipids Triglycerides, Phospholipids, and Sterols Dr. Khadija Hassan Objectives: Understand functions of fats. Recognize the types of fat. Identify the food sources of fats. Understand the daily requirement of fat. Discuss about cholesterol. Definition of Lipids Substance which are insoluble in water but soluble in organic solvents such as ether, chloroform and benzene.  N.B. the terms “oil", "fat", and “lipids" are often confused. "Oil" normally refers to a fat with short or unsaturated fatty acid chains that is liquid at room temperature, while "fat" may specifically refer to fats that are solids at room temperature. Lipids are fatty, waxy, or oily compounds that are soluble in organic solvents and insoluble in polar solvents such as water. Function of Fat Storing and providing energy. Chemical messengers. Cholesterol formation. Regulating body temperature. Formation of Prostaglandin and its role in inflammation. Membrane lipid layer formation. Problems Associated with excess Fat Fat is often associated with cholesterol and health problems. Excessive amounts of fat taken with meals interfere with digestion and, of course, if persisted in, will result in obesity. Being overweight is the cause of many troubles in the body, besides much inconvenience. Types of Fat Fatty Acids are the basic chemical units or organic acids which make up fat. All fat is one of three types of fatty acid. 1. Saturated 2. Unsaturated  Polyunsaturated  Monounsaturated 1-Saturated oRaise LDL or bad cholesterol. oAnimal sources: o Milk, cream, cheese, butter, meat, and poultry. oPlant sources o Coconut and palm oil. oCholesterol levels in the blood are related to the amount of saturated fat eaten. Polyunsaturated Better than saturated fats. - They are found in vegetable oils and fish. - Seem to help lower cholesterol levels.  Monounsaturated - The best type of fat. - It is found in olives, avocados, nuts, and olive, canola and peanut oils. - Most margarines and hydrogenated vegetable oils are highly monounsaturated. - These seem to lower LDL and raise HDL levels. - All three types of fats have the same number of calories. Lipid Classification: 1. Triglycerides (Neutral fats) 2. Phospholipids: Contain phosphate 3. Sphingolipids: Contain sphingosine. 4. Glycolipids: Contain carbohydrate 5. Steroids: Are high molecular weight compounds include cholesterol. 6. Waxes: Are esters of fatty acids with alcohol. Age group Normal range of cholesterol in blood 1-20year 120-230mg\100ml 21-30 year 120-240mg\100ml 31-40year 140-260mg\100ml 41-50year 150-290mg\100ml 51-60year 160-300mg\100ml Recommended amount of Fat For 2,000 calorie: Recommends 6 teaspoons of oil per day. 10% of total calories should come from fat, About 22 grams of fat/day. Important Sources of Fat 1) Animal fats : They are obtained from: Animal foods: Full cream milk, cheese, egg yolk and fatty meats of animals, poultry and fish Prepared Fat : Cream, butter, and cooking fat ghee 2) Vegetable oils Plant foods: Sesame, olives, peanuts and nuts Prepared Oils: Prepared from variety of plant seeds as olives and corn Comparison of dietary fats CHOLESTEROL A fat-like substance made by the body which is manufactured by the liver from the fatty foods we eat and plays a vital part in allowing the body to function normally. Useful effects of cholesterol Build the structure of cell membranes. Make hormones like Estrogen, testosterone and adrenal hormones. Help your metabolism work efficiently, cholesterol is essential for your body to produce vitamin D. Produce bile acids, Digest fat and absorb important nutrients. A high cholesterol and saturated fat diet Elevate the "blood cholesterol level" Plaque can build up in the arteries (atherosclerosis) Heart attack and stroke. CHOLESTEROL The body produces all the cholesterol it needs, Sources: All animal products, such as Meat, dairy, egg yolks, and parts of animals that walk, swim, or fly (like chicken legs, fish, or wings) Cholesterol is not found in foods of plant origin. Types of CHOLESTEROL “Good” and “Bad” cholesterol. 1. LDL or low-density lipoprotein takes cholesterol from the liver to wherever it is needed. Excess amounts of LDL can build up on artery walls and increase risk for heart disease. LDL is the “bad” cholesterol. 2. HDL or high-density lipoprotein, the “good” cholesterol, picks up excess cholesterol and takes it back to the liver for excretion. (Food for Life)  Normal range 3.6 – 7.8 mmol / liter. Level above 6mmol/liter is considered as high. Risk factor for arterial disease.  Recommended target ≤ 5 mmol/ liter. Enjoy low- fat foods for good heart health. Cholesterol in selected foods  “Cholesterol” and Disease A Desirable Blood Lipid Profile Total Cholesterol: < 200 mg / 100 mL LDL Cholesterol: < 130 mg / 100 mL HDL Cholesterol: > 35 mg / 100 mL Triglycerides: < 200 mg / 100 mL Atherosclerosis and Cardiovascular Disease  Coronary Disease and Heart Attack Fats on food labels  Alternatives to Fat Why do processors use fat replacers? Students activities Carbohydrate: i.e. guar gum, carrageenan, maltodextrin Protein: i.e. protein from soy, milk, egg white  Energy Nutrients Assume a 2000 kcal / day diet % Carbs: ? % Lipids: ? % Proteins: ?  Energy Nutrients Assume a 2000 kcal / day diet % Carbs: 55% x 2000 kcal = 1100 kcal % Lipids: 30% x 2000 kcal = 600 kcal % Proteins: 15% x 2000 kcal = 300 kcal 275 g Carbs, 67 g Lipids, 75 g Protein Free Dieting Calorie Calculator for Macronutrients CARB PROTEIN FAT grams per 225g 150g 55g day grams per 45g 30g 11g meal calories per 900 cals 600 cals 500 cals day calories per 180 cals 120 cals 100 cals meal