NTDT 200.docx

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Nutrition and Dietetics
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Mary Ann Eastep

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NTDT 200: Nutrition Concepts – Section 15 Maryann Eastep Chapter 1: An Overview of Nutrition Nutrition- the science of nutrients in foods and their actions within the body; the study of human behaviors related to food & eating Foods- products derived from plants/ animals that can be taken into the body to yield energy & nutrients for the maintenance of life & the growth and repair of tissues Chronic Diseases- slow progression/long duration Ex: Diabetes, Cancer Diet- the foods and beverages a person eats/drinks Food Choices: 1. Preferences- sugary, salty, fatty: Genetics/Hormones 2. Habit- familiarity 3. Ethnic Heritage & Regional Cuisine- ethnic foods: associated with culture a. Cultural competence: awareness and acceptance of cultures and our ability to interact with them 4. Social Interactions- hospitality/ socializing with others 5. Availability, Convenience & Economy- low cost of fast food is easier economically yet less nutritious 6. Positive & Negative Associations- certain events & experiences can influence our feelings towards some foods 7. Emotions- response to stimuli 8. Values- Religion, Politics, environmental standards 9. Body Weight & Image- follow different fads of diets or popular foods 10.Nutrition & Health Benefits a. Functional Foods- (Designer foods, nutraceuticals) foods that provide health benefits beyond their nutrient contributions Phytochemicals- non- nutrient compounds found in plant foods that have biological activity in the body; fight cancer/ infections Energy- capacity to do work; energy in food is chemical energy: mechanical, electrical & heat Nutrients- chemical substances obtained form food & used in the body to provide energy, structural materials and regulating agents to support growth, maintenance and repair of body tissues (Ciara Lucas Prefers Very Mature Women) 1. Carbs 2. Lipids 3. Proteins 4. Vitamins- organic, essential nutrients required in small amounts by the body for health; vulnerable to destruction by heat, light & chemicals; do not provide energy 5. Minerals- inorganic, some are essential nutrients required in small amounts by the body for health; do not provide energy 6. Water- medium for transporting vital minerals to cells & carrying waste products away from them; H2O Inorganic- not containing carbon or pertaining to living things Organic- substance/molecule containing carbon-carbon bonds or carbon-hydrogen bonds found in all living things Essential Nutritients- nutrients a person must obtain from food because the body cannot make itself in sufficient quantity to meet its needs Energy-yielding Nutrients- breakdown to yield energy ( Carbs, Fats, Protiens ) Calories- measures energy released from carbs, fats and protiens 1. kCal- 1 kCal is the amount of heat necessary to raise the temperature of 1 kg of water 1 °C Energy Density- a measure of the energy a food provides relative to the weight of the food  1 g Carb  4 kCal energy  1 g Protein  4 kCal energy  1 g Fat  9 kCal energy  1 g alcohol  7 kCal energy Genome- complete set of genetic materal (DNA) in an organism or cell Nutritional Genomics- science of how nutrients affect the activities of genes and how genes affect the interactions btetween diet and disease Anecdote- personal account of an experience/ event; not reliable scientific information Survey Techniques & Terminology: Randomization- subjects are chosen randomly from the same population by some method involving chance Placebo Effect- result of expectations  Placebo- pills of similar appearances & taste containing an inactive ingredient Blind Experiment- extent of belief/unbelief must be the same in both groups (control and experiment) Double-Blind Experiment- when both subjets and researchers do not know which subjects are in which group Positive Correlation- both variables change in the same direction Negative Correlation- two variables change in opposite directions Validity- conclusions to be well supported by evidence Peer Review- findings from a study submitted to a board for review & rigorously evaluate the study to ensure the scientific method was followed Replication- replicate a study to either confirm or disprove findings Dietary Reference Intakes (DRI’s)- a set of nutrient intake values for healthy people in the United States & Canada  EAR- Estimated Average Requirements- average sufficient for each nutrient that appears sufficient for HALF of the population o Used for groups: schools, military  RDA- Recommended Dietary Allowances- Once a nutrient requirement is established, the committee must decide what intake is recommended for everyone (98% of individuals)  AI- Adequate Intakes- average amount of a nutrient that a group of healthy people consume  UL- Tolerable Upper Intake Levels- somewhere beyond the recommended intake is a point beyond which a nutrient is likely to become toxic; Max daily amount safe for most healthy people EER- Estimated Energy Requirement- the average dietary intake that maintains energy balance & good health in a person of a given age, gender, weight & height & physical activity; no upper level: any excess food  gain weight AMDR- Acceptable Macronutrient Distribution Range- ranges of intakes for the energy nutrients that provide adequate energy & nutrients & reduce the risk of chronic diseases  45-65% kCal/ Carb  20-35% kCal/ Fat  10-35% kCal/Protein Malnutrition- any condition cause by excess/ deficient food energy/nutrient intake or by an imbalance of nutrients Undernutrition- deficient energy or nutrients Overnutrition- excess energy or nutrients Nutrition Assessment- analysis of a person’s nutrition status that uses historical info, anthropometric measurements, physical exams & lab tests 1. History- drug use, family history, economic background, diet, ethnicity 2. Anthropometric- physical measures: height, weight, waist, skin fold 3. Physical Exams- hair, eyes, skin, nails 4. Lab tests- blood, urine Overt- easy to observe, physical signs Covert- hidden Primary Deficiency- nutrient deficiency caused by an inadequate dietary intake of a nutrient; diet Secondary Deficiency- deficiency due to disease or drug interaction that reduces absorption, accelerates use, hastens excretion or destroys nutrients; health history Subclinical Deficiency- in early stages before the overt signs have appeared; declining nutrient stores National Surveys/Initiative: “Healthy People”- national public health initiative by US Department of Health & Human Services that identifies the most significant preventable threats to health & tries to eliminate it; set for a goal of 10 years “What We Eat in America”- identifies the kinds and amounts of food people eat “NHANES”- examines people using anthropometrics, biochemistry Macronutrients- body requires them in large amounts; carbs, proteins, fats (g/day) Micronutrients- required in small amounts; vitamins, minerals (mg/day) Risk Factors- condition associated with an elevated frequency of a disease but not proved to be casual; when the factor is present, likelihood of disease increases Chapter 2: Planning a Healthy Diet Eating Pattern- customary intake of foods and beverages over time 6 Basic Diet Planning Principles: 1. Adequacy- providing all the essential nutrients, fiber and energy in amounts sufficient to maintain health 2. Balance- Providing food in proportion to one another and in proportion to the body’s needs; whole grains, veggies, meats, etc. 3. kCal (Energy) Control- management of food energy intake; key is to eat foods with high nutrient density 4. Nutrient Density- deliver most nutrients for the least food energy; ND:mg of nutrient/kCal a. Empty kCal Foods- contribute energy but lack protein, vitamins and minerals b. Nutrient Profiling- ranking foods based on their nutrient composition 5. Moderation- providing enough, but not too much of a substance a. Solid fats- not liquid at room temperature b. Added sugars- kCaloric sweeteners that are added to foods during processing, preparation & at table; not naturally occurring 6. Variety- eating a wide selection of foods within & among the major food groups Dietary Guidelines for Americans: revised every 5 years, 30-60 mins of exercise most days 1. Balance calories to maintain weight 2. Food components to reduce 3. Foods & nutrient to increase 4. Building healthy eating patterns Healthy Eating Index- assesses how well a diet meets the recommendations of the “DGA”^ Food Group Plans- diet planning tools that sorts foods into groups based on nutrient content and then specify that people should eat certain amounts of foods from each group Vegetables: 1. Dark Green- B vitamin folate 2. Red & Orange- Vitamin A 3. Legumes- iron & protein a. Plants of the bean & pea family with seeds that are rich in protein compared with other plan-derived foods 4. Starchy- carb energy 5. Others- others & same Portion Sizes- the quantity of a food served or eaten at one meal or snack; not a standard amount Exchange Lists- diet planning tools that organize foods by their proportions of carbs, fat & protein. Foods on any lists can be used interchangeably Processed Foods- treated to change their physical chemical, microbiological or sensory properties; lost valuable nutrients Fortified- addition of nutrients to foods that were either insignificant or nonexistent; prevent nutrient deficiencies or balances the total nutrient profile of a food;  OJ w/ calcium Grains: Refined- coarse parts of a food are removed  Wheat: refined into flour, the brain, germ & husk are removed, leaving only the endosperm Enriched- added nutrients to a food to replace loses that occur during processing so the food will meet a specific standard  Folates, niacin, b1, b2, iron, Mg Whole Grain- grain that maintains the same relative proportions of starchy endosperm, germ & bran as the original (all but the husk) Vegetables:  “Think variety, think color”  Dark green & leafy, red, orange  Good source of vitamins, minerals & fiber  Vitamin A, C, K, E, Folate, Mg, K & Fiber Fruits:  Vitamins, minerals, fiber & phytochemicals  Folic Acid: Vitamin A,C  Different colors Protein Foods:  Vitamin B, E, iron, zinc & Mg  Meats, eggs, legumes, soy products, nuts & seeds  Textured Veggie Proteins- processed soybean protein used in vegetarian products; soy burgers Milk & Dairy Products: Imitation Foods- substitute and resemble another food but are nutritionally inferior in regards to vitamin, mineral & protein content (cheese products) Food Substitutes- foods that are designed to replace other foods Nutrition Facts Panel: Serving Sizes- creates standards for foods & facilitates comparable shopping Nutrition Quantities: Daily Values- reference values developed by the FDA specifically for use on food labels Percent Daily Value (%DV)- recommendation found in a specified serving of food for key nutrients based ` 1) Total food energy; energy from fat 2) Total fat; saturated fats; trans frat; cholesterol 3) Sodium content 4) Total carbs; dietary fiber 5) Sugars, proteins 6) Vitamin A, C & iron Nutrient Claims: statements that characterize the quantity of a nutrient in a food  “good source of fiber,” “rich in calcium” Health Claims: statements that characterize the relationship between a nutrient or other substance in a food & a disease/ health related condition  diets low in sodium may reduce risk of high blood pressure” Structure-Function Claims: characterize the relationship between a nutrient/ other substance in a food & its role in the body  “Improve memory,” “build strong bones” Discretionary kCalorie Allowance: kCalories remaining in a person's energy allowance after consuming enough nutrient-dense foods Food Labels: Products not required to have a food label:  Those contributing few nutrients  Produced by small businesses  Made & sold in the same establishment Ingredient Lists:  All packaged foods  Listing of all ingredients o Descending order of predominance Serving Size:  FDA- established specificed SS for various foods; ice cream= ½ cup, beverages= 8oz (all labels for given products use same serving size ) Restaurant Menu Labeling:  March 23, 2010: Restaurants & Retail locations with 20+ locations must post nutritional information visibly Chapter 3: Digestion Absorption- majority of absorption happens in the small intestine;  10 feet long & surface area of a tennis court Lumen- inner space within the GI tract Bolus- mouthful of food chewed & swallowed; amount Chyme- bolus grinded into a semiliquid mass Techniques: 1. Simple diffusion- some nutrients are absorbed by simple diffusion, cross into intestinal cells freely 2. Facilitated diffusion- need a specific carrier to transport them from one side of the cell membrane to the other 3. Active transport- move against the concentration gradient Anatomy: 1. Villi- select & regulate nutrients absorbed 2. Microvilli- trap and transport nutrients into cells; enzymes & pumps act on different nutrients (a major site of nutrient absorption) 3. Crypts- Tubular glands, secrete intestinal juices into small intestine 4. Goblet cells- responsible for mucus secretion Transportation: 2 Transport Pathways: 1. Bloodstream: water soluble nutrients and the smaller products of fat digestion go directly to the liver 2. Lymphatic System: larger fats and fat-soluble vitamins and bypass liver at first a. Chylomicrons- large fat & protein Vascular System- blood flows continuously; the heart acts as a pump Blood-  Delivers oxygen and nutrients to tissues  Removes carbon dioxide and wastes  Blood flow: o Special routing for digestive system o Blood comes to digestive system via artery o Leaves digestive system (small intestine) via hepatic portal vein** to liver o Liver blood leaves via hepatic vein to heart Liver- major metabolic organ  Kst position in nutrient transport  1 to receive nutrients absorbed from GI tract (small intestine) **  Prepared absorbed nutrients for use by the body  Defends by detoxifying harmful substances  Prepares waste products for excretions Lymph System-  One-way route for fluid from tissue spaces to enter blood  Circulation between cells; no pump  Entry into bloodstream o Much of lymph collects in thoracic duct which opens into the subclavian vein & into bloodstream  Nutrients- large fats & fat-soluble vitamins  Bypasses liver at first Health and Regulation of GI Tract 4 Factors influencing GI functions 1. Physical immaturity- babies spitting up, sphincter poorly controlled 2. Aging- elderly constipation, wall looses elasticity and strength 3. Illness 4. ___ - gi health depends on adequacy Health of GI tract depends on:  Healthy supply of blood- cells weak, inflamed without adequate blood  Lifestyle factors- sleep, PA, mental status  Types of food eaten- balance moderation, adequacy, variety Gastrointestinal bacteria- 10 trillion “flora”; few in stomach, more in intestines Most are not harmful.  Benefits: Alleviate diarrhea, constipation, IBD, ulcers, allergies, lactose intolerance, protect against colon CA, and enhance immune function  Functions: digestion of fibers (prebiotics: encourage and promote growth of bacteria) & complex proteins; vitamin production (b6 & 12, folate, vitamin k) Factors influencing bacteria presence:  pH  Peristalsis: wavelike muscular contractions of the GI tract that push its contents along  Other microorganisms  Diet- probiotics: living microorganisms found in foods/supplements, beneficial to health (yogurt) Homeostasis- survival depends on body conditions staying the same; if things change too far from the “norm” the body must make changes to bring it back to normal ex: regulation of digestion, temperature, blood pressure  Endocrine System (Hormonal) & Nervous System (nerves)- food in GI tract stimulates and or inhibits digestive via hormones or nerves Feedback Mechanism-  Certain condition demands a response  Response to change condition  Changes then cuts off response (self correcting)  GI hormones- page 85 o Secretin- acidic chyme from stomach  duodenal wall in small intestine secretin (hormone)  pancreas  bicarbonate (neutralizes) o Fat  intestinal wall  CCK(2 jobs)  gall bladder: bile  pancreas: bicarbonate/enzymes o Pancreas: digest in response to diet  Carbohydrases  carbs  Proteases  proteins  Lipases  fat CCK- released in response to fat or PRO in intestine; fat & protein take longer to digest, CCK slows the digestive process of fat & protein Chapter 4: The Carbohydrates: Sugars, Starches & Fibers Carbohydrates- compounds composted of carbon, oxygen, and hydrogen arranged as monosaccharides or multiples of monosaccharaides; most have a ratio of one carbon to one water molecule  Good sources of Carbs: o All plant foods:  Whole grains  Vegetables – “starchy” & non-starchy  Legumes  Fruits o Milk/Milk Products Monosaccharide- carbs of this formula generate a ring; 1 CHO 1. Sugars- simple carbohydrates composed of monosaccharides or disaccharides a. Glucose- a monosaccharide (part of every disaccharide), sometimes known as blood sugar in the body or dextrose in foods; provides nearly all brain energy; glucose & glycogen prove ½ of all energy b. Fructose- a monosaccharide; sometimes known as fruit sugar, found abundantly in fruits, honey and saps; the sweetest of sugars c. Galactose- a monosaccharide; occurs naturally in foods in very small amounts Disaccharides- pairs of monosaccharides linked together 1. Maltose- disaccharide composed of two glucose units  Produced whenever starch breaks down, or during the fermentation process of alcohol 2. Sucrose- disaccharide composed of glucose and fructose; sweetest of disaccharides, accounts for the natural sweetness of fruits, vegetables and grains; table/cane sugar 3. Lactose- combination of galactose and glucose; milk sugar- contributes half the energy provided by fat-free milk 4. Condensation- chemical reaction in which water is released as two molecules combine together to form one larger product  Links two monosaccharides together and forms h2o 5. Hydrolysis- chemical reaction in which one molecule is split into two molecules with H added to one and OH to the other (from h2o) Polysaccharides- many monosaccharides linked together (chains) 1. Glycogen- animal polysaccharide composed of glucose; a storage form of glucose manufactured and stored in the liver and muscles; Not a significant food source of carb & is not counted as a dietary carb in foods a. Storage form of energy in the body 2. Starches- plant polysaccharides composed of many glucose molecules 3. Fibers: Dietary Fibers: in plant foods, the non-starch polysaccharides that are not digested by human digestive enzymes, although some are digested by GI tract bacteria a. Soluble Fibers: non starch poly saccharides that dissolve in water to form a gel; pectin in fruit to thicken jellies i. Found in oats, barley, legumes, citrus fruits ii. Protects against heart diseases & diabetes b. Insoluble Fibers- do not dissolve in water & do not form gels; less fermented (broken down) in GI tract i. Found in whole grains: bran & veggies ii. Promotes regular bowel movements; alleviate constipation iii. Prevents diverticular disease CHO Digestion: Starches (polysaccharides)  Disaccharides (m,s,l)  Monosaccharides (g,f,g)  Liver converts Galactose & Fructose into Glucose Ultimate Goal- breakdown into small molecules; glucose for absorption and use: Begins in: 1. Mouth (small amount) a. Salivary amylase from saliva i. Amylase- an enzyme that hydrolyzes amylose (a form of starch). Amylase is a carbohydrase, an enzyme that breaks down carbohydrates 1. Hydrolyzes starch to shorter polysacch. b. Very little digestion occur here 2. Stomach a. Stomach acid & protein-digesting enzymes inactivates amylase; digestion ceases here b. Juice contain no digestive enzymes to digest CHO c. Role of fiber: i. Lingers, delays gastric emptying (satiety) 3. Small Intestine a. Most carb digestion takes place b. Pancreatic amylase comes through pancreatic duct & breaks down polysacchs to short glucose chains c. Specific disaccharide enzyme (outer membranes of intestinal wall) i. Maltase- maltose to 2 glucose ii. Sucrase- sucrose into 1 glucose & 1 fructose iii. Lactase- lactose into 1 glucose & 1 galactose d. AT THIS POINT, ALL POLYSACH & DISACH  MONOSACH 1-4 hours after a meal, all sugars & most starches have been digested 4. Large Intestine a. Only the fibers are left- attract h2o, softens stools for passing b. Bacteria ferment some fiber  h2o, gas short chain fatty acids c. Short chain fatty acids can be used by colon for energy CHO Absorption: Mainly occurs in the small intestine  Active transport- requires energy & carrier o Glucose & Galactose  Facilitated Diffusion- requires carrier o Fructose  Liver- blood circulates from small intestine o Liver takes up & converts fructose and galactose Lactose Intolerance:  Highest immediately after birth  Declines with age- drops dramatically in childhood, 30% people retain enough lactase Not enough lactase  lactose molecules not digested attracted h2o  bloating, abdominal distention, and diarrhea Causes: damaged intestinal villi due to-  Disease  Medicines  Prolonged diarrhea`  Malnutrition Dietary Changes:  Manage dairy consumption rather than restriction  Many can consume 6 grams lactose (1/2 c. milk) without symptoms  Increase milk products gradually, take with other foods in meals spread out the intake of lactase Fermented milk products- yogurt with live bacteria, kefir (fermented milk) seems to improve lactose intolerance  Why?: GI bacteria- change bacteria in number, type & activity  improves symptoms … NOT reappearance of the missing enzyme CHO Metabolism: Storing glucose as glycogen  Liver storage 1/3 of glycogen o (after meals, blood sugar rises) Condensation links excess glucose into glycogen o (between meals, blood sugar lowers) Hydrolysis (breakdown) of glycogen for release of glucose into bloodstream when needed o Muscle storage 2/3 glycogen  Hoards glycogen for exercise  Fuels most of body’s cells o Preferred source for brain, nerve cells, and developing red blood cells  Cellular breakdown of glucose: 1. Enzymes break glucose in half 2. Small fragments make energy 3. Supplies of glucose lasts ½ a day during rest; only a few hours with activity Depleted Glycogen Stores  Fat cannot be significantly converted to glucose  Making glucose from protein (from liver& skeletal muscle) o Protein has other, more important roles  Gluconeogenesis- conversion of non-carbohydrate source into glucose; “making new glucose”  Protein-sparing action: only adequate dietary CHO intake can prevent PRO use for energy  PS Action of CHO is providing energy that allows protein to be used for main purposes  With less CHO, fat takes alternate pathway  (Fat metabolism shifts breakdown incomplete) o Fat fragments combine forming ketones  Ketone body- compounds produced during the incomplete breakdown of fat when glucose is not available in the cells (Starvation state)  Ketosis- ketone production exceeds its use, accumulated in blood & disturbs acid-base balance o Carbohydrates needed for protein sparing & prevention; 50-100g/ day needed for PRO sparing & prevention of ketosis Excess Glucose 1. Fat conserved- body simply uses more glucose than fat for fuel (uses more CHO in fuel mix) a. If glucose balance is not restored  2. Fat created- liver breaks down extra glucose and turns into fat a. Uses excess glucose to make body fat Constant Supply of Blood Glucose: Steady supply in blood stream  Small intestine- from food  Liver- from glycogen breakdown using hydrolysis or gluconeogenesis Hormones: Glucose from blood into cells when blood sugar is high 1. Insulin (Pancreas)- controls transport of glucose from the bloodstream into the muscle and fat cells Brings glucose out from storage when blood sugar is low 2. Glucagon (pancreas)- elicits release of glucose from liver glycogen stores 3. Epinephrine/stress (adrenal gland)- signals liver to release glucose; Purposes of these is to increase blood sugar levels Balancing within the normal range  Balance meals at regular intervals  Balance of CHO, including fibers, little fat so glucose enters blood gradually  Blood Sugar Ranges: o NORMAL- 70-100 mg/dl o Prediabetes- 120-125 mg/dl o Diabetes- > 126 mg/dl Diabetes-  Chronic disorder of carbohydrate metabolism,  Usually result from insufficient/ineffective insulin  Blood glucose rises after a meal, remains above normal  Incidence has risen dramatically; 7th among leading causes of death o Underlies/contributes to several major diseases; heart disease Type 1: the less common type; pancreas produces little or no insulin  Genetically susceptible; commonly occurs in childhood  Body attacks its own insulin  Autoimmune disorder- body develops antibodies to its insulin & destroys pancreatic cells that produce insulin o Pancreas loses ability to produce insulin  Insulin injections or pump (no oral) Signs/Symptoms: 1. Weight loss 2. Hunger & excessive eating  polyphagia 3. Ketones in blood, urine, breath (from breakdown of protein and fat) 4. Frequent urination  polyuria 5. Excessive thirst  polydipsia Type 2: the more common type; cells fail to respond to insulininsulin resistance  Muscle & adipose cells cannot remove glucose from blood, high levels of blood glucose/ insulin  Hyperinsulineia- high levels of insulin in blood  Insulin Deficiency- amount of insulin is insufficient to compensate for diminished effects in cells  Tends to occur as a consequence of obesity, smoking, aging, lack of exercise, poor diet Signs/Symptoms: 1. Weight gain 2. Hunter & excessive eating  polyphagia 3. Frequent urination  polyuria 4. Excessive thirst  polydipsia Hypoglycemia-  Abnormally low blood glucose concentration  Symptoms: weakness, rapid heartbeat, sweating, anxiety, hunger trembling  Caused by poorly managed diabetes  Prevalence- rare in healthy people  Replace refine CHO in diet  Increase fiber-rich CHO  Adequate protein with means; smaller frequent meals Chronic Complications of Diabetes:  Blurry vision  Poor circulation  Blood vessel & nerve damage  Atherosclerosis- plaque in the artery walls Recommendations for Diabetes: 1. Total CHO intake (g)- consistent intake 2. Carbohydrate sources a. Fibers & sugar 3. Dietary Fat - <200mg cholesterol / <7% Saturated Fat 4. Protein a. Kidney function- watch high PRO intake 5. Alcohol in moderation Glycemic Response- the extent to which a food raises the blood glucose concentration and elicits an insulin response  How quickly glucose is absorbed after meals, how high blood glucose rises, and how quickly it returns to normal  Glycemic Index: a method of classifying foods according to their potential for raising blood glucose; influenced by fiber content, preparation method, other food in meal, individual tolerance o Low Glycemic Index- practical way to improve glucose control  Improve blood lipids  Reduce risk of heart disease  Weigh management Glycemic Index Generalizations: 1. Low- legumes, milk/milk products 2. Moderate- whole grains, fruits 3. High- processed foods, snack foods, ready to eat cereals DRI- Added Sugars No more than 25% of day’s total energy Impact on other food groups- displaces nutrients (2,000 kcal = 500 kcal = 125 g = 30 tsp.) American Heart Association: 100 kcal for women- 6 tsp. 150 kcal for men- 9 tsp. WHO & FAO: Restrict added sugars to 10% of total energy Alternative Sweeteners: 1. Artificial Sweeteners- sugar substitutes that provide negligible energy a. Nonnutritive sweeteners 2. Stevia- herbal sweetener derived from a plant whose leaves have been used by South Americans to sweeten beverages a. GRAS- Generally recognized as safe by FDA 3. Sugar Alcohols- sugarlike compounds that can be derived from fruits or commercially produced from dextrose; “Nutritive Sweeteners”- sweeteners that yield energy, including both sugars and sugar alcohols a. Provide some kcalories b. Absorbed more slowly than other sugars and metabolized differently in the human body c. Not readily utilized by ordinary mouth bacteria Health Effects of Starches and Fibers:  Increase whole grains  Heart disease- increase soluble fibers  Diabetes- increase soluble fibers slow glucose absorption  GI health- ample fluids for increase in fiber  Weight management- maintain healthy weight  Cancer- prevent colon cancer DRI for carbs  45-65% of energy requirement RDA for carbs  130 grams per day Fiber: DV: 11.5 grams per 1000 calories (25 g) DRI: 14 grams per 1000 calories (25-35g) No Upper Limit (UL) Chapter 5: The Lipids: Triglycerides, Phospholipids & Sterols Lipids- family of compounds that includes triglycerides, phospholipids & sterols; characterized by insolubility in water  Triglycerides  Phospholipids  Sterols Fatty Acids- organic compounds composed of a carbon chain with:  Hydrogen’s attached  Acid group at one end (COOH)  Methyl group at other end (CH3)  Normally even number of carbons o 18 carbon fatty acids abundant in food o vary in length  12-24 carbons  long chain fatty acids of meats, fish, & veggie oils are most common  6-10 carbons  medium chain  < 6 carbons  short chains Saturated Fatty Acid- fully loaded with all its hydrogen atoms and contains only single bonds between its carbon atoms Unsaturated Fatty Acid- lacks hydrogen atoms and has at least one double bond between carbons; composed to triglycerides in which most of the fatty acids are unsaturated  Point of Unsaturation- the double bond of a fatty acid, where hydrogen atoms can easily be added to the structure; structure bends  Monounsaturated Fatty Acid- lacks two hydrogen atoms and has one double bond between carbons; composed of triglycerides in which most of the fatty acids are monounsaturated (abundant in olive/canola oil) o 1 double bond; oleic acid in olive/ canola oil o Omega 9 groups (oleic acid)  Polyunsaturated Fatty Acid- lacks four or more hydrogen atoms and has two or more double bonds between carbons; composed of triglycerides in which most of the fatty acids are polyunsaturated o 2 double bonds; linolenic acid o 3 double bonds; lineoleic acid in walnuts, flaxseeds, veggie oils  Essential and body cannot make it: o Lenolenic- omega 3 FA (double bond)  Sources: salmon, nuts, vegetable oils  2 types: DHA 22 c, EPA 20 c  Found in eyes, brain; normal growth, cognitive development o Lenoleic – omega 6 FA (double bond)  Sources:  Deficiency produces deficiency in arachidonic acid- conditionally essential Conditionally Essential- nonesstial nutrient must be supplied by diet in special circumstances (arachidonic acid must be supplied in diet due to linoleic acid deficiency) Triglycerides- glycerol backbone with three fatty acids attached Chief form of fat in: 1. Diet 2. Major storage form of fat in the body Formed via condensation reactions Degree of Unsaturation Influences 1. Firmness at room temperature a. Polyunsaturated fats more liquids b. Saturated Fats more solid c. Exceptions: cocoa butter, palm oil, palm kernel oil, coconut oils  tropical oils & are saturated but act like unsaturated fats d. Length of carbon chain: shorter chains are softer 2. Stability a. Oxidation and spoilage of fats i. Oxidation- process of a substance combining with oxygen, oxidation reactions involve the loss of electrons b. Polyunsaturated fats are most susceptible c. Monounsaturated fats are slightly less susceptible d. Saturated fats, most resistant to oxidation, least likely to become rancid/spoil 3 Ways Manufacturers Protect Fat Foods from Rancidity  Seal in air tight, nonmetallic containers, protected from light & refrigerated  Add antioxidants  Hydrogenation 3. Hydrogenation- Hydrogens are added to monounsaturated/ polyunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated and more resistant to oxidation; points of unsaturation are saturated by adding Hydrogen a. Advantages i. Protects against oxidation, extends shelf life ii. Alters textures of foods, liquid veg. oils more solid, (more spreadable, flaky crusts) iii. Produces trans-fatty acids 4. Trans-fatty Acids- a. Configurations- most double bonds are cis i. Cis  H+ on same side of double bonds b. Trans  H+ are on opposite sides of double bonds i. Man made through hydrogenation, act like saturated fats, increase heart disease risk & blood cholesterol ii. Few naturally occurring in meats, milk; CLA Conjugated Linoleic Acid (may have health benefits) Phospholipids- a compound similar to a triglyceride but having a phosphate (hydrophobic) molecule and choline in place in one of the fatty acids(hydrophilic); soluble in fat & water  Lecithin- best known phospholipid; has one glycerol with 2/3 attachment sites occupied by fatty acids like those in triglycerides; third site is occupied by a phosphate group & choline molecule o Not essential- liver makes all needed- supplements are 9 kcal/gram o Fatty acid part makes phospholipids soluble in fat; phosphate group allows phospholipids to dissolve in water o Food industry uses as an emulsifier to combine water-soluble and fat-soluble ingredients that do not mix (oil & water)  Emulsifier- substance with both water soluble and fat soluble portions that promote mixing of oils and fats in watery solutions  Richest sources: eggs, liver, soybeans, wheat germ & peanuts Roles: 1. Constituent of cell membranes 2. Aid fat-soluble substances to pass in and out of cells o Vitamins and hormones Sterols- compounds containing a four-ring carbon structure with any variety of side chains attached 1. Cholesterol- most common; only sterols from animals contain significant amounts of cholesterol  meat, eggs, seafood, poultry & dairy products a. Liver makes 800-1500 mg/day 2. Naturally found in plants a. Inhibit cholesterol absorption, lower blood cholesterol levels  Roles: o Important body compounds: bile acids, sex hormones, adrenal hormones, Vitamin D & cortisol o Endogenous- cholesterol created in the body o Exogenous- cholesterol from outside the body o Plaque- accumulation of fatty deposits, smooth muscle cells, and fibrous connective tissue that develops in the artery walls in atherosclerosis o Atherosclerosis- type of artery disease characterized by plaques on the inner walls of the arteries Lipid Digestion: Hydrophobic- separate from water fluids of GI tract (water fearing) Digestive enzymes are hydrophilic (water loving) Goal: Dismantle trigylcerides into small molecules: monoglycerides, fatty acids, glycerol 1. Mouth: Fat digestion begins slowly a. Hard fats begin to melt when they reach body temp. b. Lingual Lipase- released by salivary gland at the end of tongue i. Active role in fat digestion in infants ii. Minor role in adults 2. Stomach: a. Muscle contractions propel contents towards pyloric sphincter b. Remaining partially digested food back into stomach c. Churning grinds, mixes, and disperses the solid pieces into small fat droplets i. Help expose fat for attack by gastric lipase enzyme- attacks fat droplets; performs best in acidic ph in the stomach d. Negligible fat digestion 3. Small Intestine: a. Triggers release of CCK i. (CCK) Cholecystokinin- signals gallbladder to release its stores of bile  acts as emulsifier ii. Bile acids pair up with amino acids  hydrophilic and sterol end is hydrophobic 1. Structure causes bile to act as an emulsifier, drawing fat molecules into the surrounding watery fluids a. Fats are fully digested as they encounter lipase enzymes from the pancreas & small intestine b. Pancreatic lipase- fats digested as exposed to lipases from pancreas and small intestine; major fat digesting enzyme 4. Hydrolysis of Triglycerides a. Pancreatic lipase remove 1 fatty acid/time, leaving a monogylceride b. Sometimes all 3 fatty acids are removed  leaving glycerol c. Phospholipids are similarly hydrolyzed d. Sterols absorbed as is Route of Bile: bile is made from cholesterol  Small intestine- emulsifies fat 1. Most of bile is reabsorbed from the small intestine & recycled –OR- 2. Trapped by dietary fibers in the large intestine and excreted a. Cholesterol is needed to create bile  excretion of bile effectively reduces blood cholesterol i. Most effective blood chol. Lowering soluble fibers: fruits, whole grains, legumes Lipids Absorption:  Small molecules can diffuse easily into the intestinal cells; absorbed directly into the bloodstream o Short & medium chain fatty acids & glycerol  Large molecules are emulsified by bile o Forms micelles- tiny spherical complexes of emulsified fats that arise during digestion  Diffuse into intestinal cells where monogylcerides & long chain fatty acids are reassembled into new triglycerides Lipids Transport: Lipoproteins- clusters of lipids associated with proteins that serve as transport vehicles for lipids in the lymph and blood; Solve the body’s challenge of transporting fat through the watery bloodstream 1. Chylomicrons- largest & least dense of the lipoproteins a. Transport diet derived lipids from the small intestine  rest of body b. Cells remove triglycerides, chylomicrons shrink; liver removes remnants from blood 2. VLDL (Very-Low-Density Lipoproteins)- type of lipoprotein made primarily by liver cells to transport lipids to various tissues in the body; composed primarily of triglycerides 3. LDL (Low-Density Lipoprotein)- as chol. Becomes the predominant lipid, VLDL becomes smaller and more dense and becomes LDL a. Circulate throughout the body; make contents available to the cells of all tissues  muscles, fat stores, mammary glands, etc. b. More saturated fat  more LDL cholesterol in blood i. Higher risk for heart attack c. Blood cholesterol linked to heart disease; “Bad cholesterol” 4. HDL(High-Density Lipoproteins)- created by the liver to remove cholesterol from the cells and carry it back to the liver for recycling or disposal  reverse cholesterol transport/ scavenger pathway a. Anti-inflammatory properties (role in controlling plaque) i. Lowers risk of heart disease b. Protective against heart disease; “good cholesterol” DESIRABLE BLOOD LIPID PROFILE: Total cholesterol <200 mg/dl LDL cholesterol <100 mg/dl HDL cholesterol >60 mg/dl Triglycerides < 150 mg/dl Health Effects of Sat Fats, Trans Fats & Cholesterol: Factors that keep LDL low and HDL high 1. Weight control 2. Diets high in MUFA or PUFA (vs. saturated fat) 3. Soluble dietary fibers 4. Phytochemicals 5. Physical activity Blood Lipid Profile- results of blood tests that reveal a person’s total cholesterol, triglycerides, and various lipoproteins Cardiovascular Disease- diseases of the heart/blood vessels throughout the body  Atherosclerosis is the main cause of CVD; when the arteries that carry blood to the heart muscle become blocked, the heart suffers damage known as coronary heart disease (CHD) o Accumulation of fatty streaks along inner arterial walls  Streaks enlarge & harden  Encasement in fibrous connective tissue o Plaques stiffen arteries and narrow passages  Elevated LDL cholesterol creates major risk  Inflammation is initial sign of cardiovascular disease; elicits inflammatory response & immune system sends in macrophages Factors: 1. Family history 2. Lifestyle factors 3. Coronary Heart Disease (CHD) is most common form a. Usually caused by atherosclerosis 4. Dietary factors- high saturated fat is more damaging than high cholesterol Coronary Heart Disease- Risk Factors:  Age, gender, family history  Not modifiable o Atherogenic diet: high in saturated fats & low in vegetables fruits, whole grains  Chol., blood pressure, diabetes, obesity, exercise, smoking  modifiable Cancer-  Links between dietary fats and cancer are weaker than CVD o Dietary fat doesn’t initiate but promotes  Breast Cancer: body fatness contributes to the risk  Colon Cancer: harmful association with foods w/ animal fats Highlight 5: 1. Saturated fat and LDL cholesterol a. Sources of saturated fat in the US i. Meats ii. Whole milk products iii. Tropical oils b. Zero saturated fat is not possible 2. Trans Fat
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