Macronutrients and their roles in maintenance of health I_ppt.pdf

GEN N105BF Food for Shape 營養 ∙ 養型 School of Nursing and Health Studies Macronutrients and their roles in maintenance of health (I) Prepared by Dr. Queenie Law Today’s lecture 1. Recognize the classification, functions and food sources of different macronutrients 2. Calculate the calories of food...

GEN N105BF Food for Shape 營養 ∙ 養型 School of Nursing and Health Studies Macronutrients and their roles in maintenance of health (I) Prepared by Dr. Queenie Law Today’s lecture 1. Recognize the classification, functions and food sources of different macronutrients 2. Calculate the calories of food and calorie requirement per day of different people What is Energy? “Calorie is an energy measurement unit” (Centre for Food Safety, 2015) 1 calorie of heat energy = ↑ 1 gram of H2O by 1 ºC 1,000 calories = 1 kilocalorie (kcal), commonly used in measuring food energy Estimation of energy requirements for healthy individuals: How much calories do we need per day? Activity Level Overweight / Obese Light activity: housework or office work Moderate activity: heavy housework and very little sitting High activity: active in physical sports or a labor-intensive occupation such as construction work The calorie required per kilogram of body weight (calories/kg) 20 30 35 40 (Hong Kong East Cluster Nutrition Information Web, 2013) Energy scale for food Carbohydrates: 4 Calories per gram Protein: 4 Calories per gram Fats: 9 Calories per gram (Dudek, 2014) Carbohydrates Major energy source in an diet, preferred fuel Three main types: monosaccharides, disaccharides and polysaccharides (complex carbohydrate) Contributes 55% - 75% of daily energy intake Food sources Monosaccharides Sugar, Syrup, Honey, and disaccharides: Molasses Complex carbohydrate: Cereal, grains and their products, starchy vegetables (Centre for Food Safety, 2015) Carbohydrates classifications Carbohydrates Simple Sugars Monosaccharides Complex Carbohydrates Polysaccharides - Starch - Glycogen Disaccharides - Fiber (Dudek, 2014) Protein For growth and body repair Used as body fuel (only when there is an insufficient intake of energy) Contributes 10% - 15% of daily energy intake Food sources Protein Meat, milk, eggs and legumes (Centre for Food Safety, 2015) Fats As a concentrated energy source Carries fat-soluble vitamins Prevents heat loss and protects organs against shock Contributes 20% - 35% of daily energy intake Food sources Fat Butter, salad dressing, deep frying foods (Centre for Food Safety, 2015) Fat classifications Fats Saturated Fat Mono-unsaturated Poly-unsaturated Fat Fat Omega-3 Fatty Acids Omega-6 (Dudek, 2014) Fatty Acids Trans Fat Saturated Fats Tend to be solid at room temperature Known as a “bad” fat, it raises blood cholesterol As the intake of saturated fat increases, so does the level of total and low-density lipoprotein (LDL) cholesterol (Dudek, 2014) Contributes not more than 10% of daily energy intake Food sources Saturated Animal fats – the fat in meat, whole-milk dairy Fats products and egg yolks Vegetable fats – palm oil, palm kernel oil and coconut oil (Centre for Food Safety, 2015) Unsaturated Fats (Centre for Food Safety, 2015) Further divided to mono- and poly-unsaturated fats Liquid at room temperature Known as a “good” fat Lower LDL cholesterol and raise high-density lipoprotein (HDL) cholesterol (Dudek, 2014) Unsaturated Fats Food sources Mono-unsaturated Fats Olives, olive oil, canola oil, peanut oil, avocado, cashews and most other nuts Omega-6 polyunsaturated fatty Acid Abundant in plant oils such safflower, sunflower, corn and soy-bean oils Omega-3 polyunsaturated fatty Acid Flaxseed, canola, soybean, walnut oils and in nuts, especially walnuts Fish oils, especially salmon, anchovy, sardines, herring and mackerel Trans Fats A specific type of fat formed when liquid oils are made into solid fats, a process known as “hydrogenation” Known as a “bad” fat Raise LDL cholesterol and serum triglyceride levels lower high-density lipoprotein (HDL) cholesterol (Dudek, 2014) Contributes not more than 1% of daily energy intake Food sources Trans Fat Hydrogenated vegetable oil, margarine, shortening, foods using partially hydrogenated vegetable oils as ingredients e.g. pastry (Centre for Food Safety, 2015) Cholesterol = Lipids? Cholesterol Cholesterol is one of the sterols. Sterol is a class of lipids. Found exclusively in animal Involves in the formation of vitamin D, bile and some hormones Cholesterol in the blood and tissues is derived from two sources: diet and endogenous synthesis. Endogenous synthesis: all body cells are capable of making enough cholesterol to meet their needs, cholesterol is not an essential nutrient Food sources Cholesterol Egg yolk, squids, cuttlefish, lard, animal fat (Centre for Food Safety, 2015) Nutrition label in Hong Kong https://www.cfs.gov.hk/english/programme/programme_nifl /files/UNDERSTAND_E.pdf Nutrition label in Hong Kong Nutrition label in Hong Kong Nutrition label (FDA) Any difference? Understand serving size By law, serving sizes must be based on the amount of food people typically consume rather than how much they should consume Reflect the amount people typically eat and drink today Exercise 1 How many cookies are in a serving? How many servings are in a package? How many calories per serving size are in this product? Exercise 1 How many cookies are in a serving? How many servings are in a package? How many calories per serving size are in this product? What Are Total Sugars? include sugars naturally present in foods and beverages, + any added sugars There is no Daily Value* for total sugars no recommendation has been made for the total amount to eat in a day What Are Added Sugars? include sugars that are added during processing of foods (such as sucrose or dextrose) foods packaged as sweeteners (such as table sugar) sugars from syrups and honey sugars from concentrated fruit or vegetable juices What Are Added Sugars? do not include naturally occurring sugars that are found in milk, fruits, and vegetables The Daily Value for added sugars is 50 grams per day based on a 2,000 calorie daily diet. Nutrients Old one New one Nutrients Vitamin D and potassium: Americans do not always get the recommended amounts Vitamins A and C: no longer required since deficiencies The actual amount (in milligrams or micrograms) in addition to the %DV must be listed for vitamin D, calcium, iron, and potassium. The Daily Values are reference amounts of nutrients to consume or not to exceed each day and are used to calculate the %DV References Centre for Food Safety. (2017). Nutrients Definition and Functions. Retrieved from https://www.cfs.gov.hk/english/nutrient/nutrient.php Dudek, S. G. (2014). Nutrition Essentials for Nursing Practice (7th ed.). New York: Lippincott Williams & Wilkins.