Nutrients that provide energy Carbs fats and oils proteins Study Guide Kcal value macronutrients Carbs 4 kcals per gram Protein 4 kcals per gram Fat 9 kcals Alcohol 7 kcals AMDR S of macronutrients Carbs 45 65 AMDR Fat 20 35 AMDR Protein 10 35 Difference between nutrient density calorie density Nutrient density comparison of nutrient content and can be macro or micronutrient Calorie Density Compares ONLY the calories per serving of a food i e 1 regular bagel vs 1 voodoo donut FDA requirements of Food Labels 1 A statement of identity 2 Net contents of the package 3 4 Manufacturer s name and address 5 Nutrition Information Ingredient list Problems with current Labels misleading calories and serving sizes and lack of info about type of sugars Key micronutrients not emphasized Hunger physiological sensation to eat Appetite psychological desire to eat Satiety the feeling of being full Anorexia physiologic need for food yet have no appetite Food goes through three processes 1 Digestion 2 Absorption 3 Elimination Nerve receptors send signals to hypothalamus feeding center of the brain to indicate if the stomach is full or empty Blood Glucose Levels trigger the release of hormones insulin and glucagon Digestion break down carbs proteins fats and vitamins to smaller molecules so the body can absorb them Mechanical digestion physical breakdown of food Occurs when peristaltic waves mix contents of stomach Chemical digestion enzymatic reactions that break down large food molecules GI tract stomach and intestines Sphincters muscles that control the passage of material from one organ to the next Salivary amylase enzyme produced by salivary glands begins chemical breakdown of carbs Minimal digestion happens in the mouth Pepsin initiates protein digestion Gastric Lipase initiates lipid digestion Proteins highest satiety value Carbs lower satiety value than fats Digestion in the stomach mechanical digestion to mix food with gastric juice and chemical digestion of proteins and fats Absorption process of taking molecules across a cell membrane and into cells of the body small amount of absorption occurs in the stomach Villi folds in the lining that are in close contact with nutrient molecules Brush border composed of microvilli that greatly increase the surface area Water soluble nutrients carb protein minerals and some vitamins portal vein transports these to the liver Fat soluble nutrients lipids and vitamins enter the lymphatic vessels that transport the nutrients to the bloodstream Peptic ulcers regions of the GI tract that have been eroded by HCL and pepsin Helicobacter pylori bacterium that contributes to the production of gastric and duodenal ulcers Carbs macronutrient Energy source especially for nerve cells Carbon hydrogen oxygen Glucose most abundant carb produced by plants component of disaccharides and complex carbs found in blood Monosaccharide one molecule Glucose fructose galactose Disaccharide 2 molecules Lactose maltose sucrose Complex carbs polysaccharides starch glycogen most fibers starch plants store glucose in form of starch glycogen stored in the liver and muscles not found in food therefore not a source of dietary carb Fiber Dietary fiber soluble fiber non digestible part of plants Functional fiber carb with known health affects which is extracted from plants and added to foods Total fiber dietary functional fiber Carbs energy Red blood cells rely only on glucose for energy Most chemical digestion of carbs occurs in the small intestine Pancreatic amylase enzyme secreted in the small intestine Monosaccharide s converted to glucose by the liver Humans do not have the enzymes necessary to digest fiber and mostly remains undigested and is eliminated with feces Level of glucose in the blood 80 120 mg Insulin and glucagon control level of glucose in the blood Gluconeogenesis the production of new glucose from amino acids Glycemix index a measure of a foods ability to raise blood glucose levels Recommended Dietary Allowance RDA 130 g day to supply the brain with glucose 45 65 of daily calorie intake should be in form of carbs AI of fiber is 14 grams per 1 000 kcal in the diet daily Proteins large complex molecules composed of amino acids Contains carbon hydrogen oxygen nitrogen Why do we need proteins Cell growth repair and maintenance Hormones enzymes fluid and electrolyte balance pH balance antibodies to protect against disease energy source 20 different amino acids are used to make 100 000 different proteins Essential amino acids 9 of 20 are essential Nonessential amino acids can be made by our bodies Proteins amino acids joined by peptide bonds Structure 1 Primary structure sequential order of amino acids 2 Secondary structure spiral shape due to chemical bonding between the amino acids 3 tertiary and quaternary structure further holding into a unique three dimensional shape that may be globular or fibrous Denaturation losing shape Results in an irreversible loss in protein function Incomplete protein doesn t contain all essential amino acids in sufficient quantities lowquality Complete protein contains sufficient amounts of all 9 essential amino acids high quality Mutual supplementation combining two incomplete proteins to make a complete protein Complementary proteins two protein sources that together supply all nine essential amino acids Digestion of proteins in stomach hydrochloric acid breaks down protein structure and activates pepsin Mouth stomach small intestine liver Protein energy malnutrition a disorder caused by inadequate intake of protein and energy Two forms Marasmus Kwashiorkor Marasmus disease resulting from severely inadequate intakes of protein energy and other nutrients Kwashiorkor disease resulting from extremely low protein intake Seen in children in other countries Lipids diverse group of molecules that are insoluble in water Three types of lipids 1 triglycerides fatty acids are classified by Carbon chain length saturation level saturated monosaturated polysaturated and shape 2 Phospholipids glycerol backbone 2 fatty acids phosphate Soluble in water transport fat in the bloodstream 3 Sterols contain multiple rings of carbon atoms block the absorption of dietary cholesterol Fats the lipid content of diets and foods AMDR for fat 20 35 of calories Cholesterol less than 300 mg per day Hydrogenation hydrogenated vs partially hydrogenated Body Mass Index BMI ratio of person s weight to the square of his her height BMI weight kg height m Limitations BMI below