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Nutrition Final1-4
into nutrition
Question | Answer |
---|---|
Nutrition | The science of foods and the substances they contain |
Food | Food is derived from plant or animal sources. Provides energy and nutrients |
Diet | The term “diet” refers to the food and beverages a person eats, drinks, and/or consumes |
Food Factors | Personal preference Taste is # 1 reason for food choices Habit/Social interaction Ethnic heritage/traditions/religion Availability, convenience, economy Positive/negative associations Emotional comfort Body weight/image Nutritional value |
Functional Foods | Provide health benefits beyond their nutrient contributions |
Nutrients | Chemical substances obtained from foods & used by the body to provide energy, structural materials, growth, maintaince/repair of tissue, disease prevention |
Six classes of nutrients | Proteins are energy yielding (4 kcal/gm) Carbohydrates are energy yielding (4 kcal/gm) Lipids are energy yielding (9 kcal/gm) Vitamins, Minerals, Water |
Organic | substances/molecule containing carbon- carbon or carbon-hydrogen bonds |
Inorganic nutrients | minerals, water |
Essential nutrients | Must be obtained from foods |
kilocalorie | the amount of energy needed to raise the temperature of one kilogram of water 1 degree Celcius |
Kilicalorie of protein | 4 kcals/gram |
kilicalories of cholesterol | 4 kcals/gram |
kilicalories of Fats | 9 kcals/gram |
45%-65% | percent total kilicalories per day for carbohydrates |
20%-35% | percent total kilicalories per day for fat |
10%-35% | percent total kilicalories per day for protein |
Energy Density | Measure of the energy a food provides relative to the amount of food (kcals/gm) |
Vitamins | Organic, Not energy-yielding, 13 Essential, Water-soluble vs. fat-soluble Vulnerable to destruction – heat, light, chemicals |
Minerals | Inorganic, Not energy-yielding, 16 Essential Indestructible Binding issues |
Water | Inorganic, Not energy yielding, Essential, Required for metabolic reactions, ~ 60% of an adult’s body weight |
Scientific Method | Define a problem, Formulate a hypothesis, Collect data, Interpret the data, Generalize the findings |
Epidemiological Studies | Cross-sectional study, Case control study, Cohort study |
cross-sectional study | Researchers observe how much/what kinds of foods groups of people eat and how healthy those people are |
Case control study | Researchers compare people who do and do not have a condition/disease, closely matching them for age/gender/key variables so that differences in other factors will stand out |
Cohort Study | Researchers analyze data from a select group of people (cohort) at intervals over a period of time |
Experimental Studies | Laboratory-based animal studies, Laboratory-based in vitro studies, Human intervention/clinical trials |
Laboratory-based animal studies | Researchers feed animals special diets that provide/omit nutrients and then observe health changes |
Laboratory-based in vitro studies | Researchers examine the effects of a variable on tissue, cells, or molecules from living organisms |
Human intervention clinical trials | Researchers ask people to adopt a new behavior (eat almonds, take a fish oil supplement, exercise daily) to determine the effectiveness of such interventions on the development/prevention of disease |
Blind Experiment | an experiment in which the subjects do not know whether they are members of the experimental group or the control group |
Experimental group | a group of individuals similar in all possible respects to the control group except for the treatment. Recieves the real treatment |
Control Group | a group of individuals similar in all possible respects to the experimental group except for the treatment. Ideally a placebo |
Correlation | the simultaneous increase, decrease, or change in two variables |
Double-Blind experiment | an experiment in which neither the subjects nor the researchers know which subjects are members of the experimental group and which are serving as control subjects until the experiment is over |
Peer review | a process in which a panel of scientists rigorously evaluates a research study to assure that the scientific method was followed |
Placebo | an inert, harmless medication given to provide comfort and hope, a sham treatment used in controlled research studies |
Placebo Effect | a change that occurs in response to expectations in the effectiveness of a treatment that actually has no pharmaceutical effect |
Hypothesis | an unproven statement that tentatively explains the relationship between two or more variables |
Replication | repeating an experiment and getting the same results |
Theory | a tentative explanation that integrates many and diverse findings to further the understanding of a defined topic |
Randomization | a process of choosing the members of the experimental and control groups without bias |
Validity | having the quality of being founded on fact or evidence |
Variables | factors that change. May depend on another or be independent |
DRI- Dietary Reference Intake | a set of nutrient intake values for healthy people in the US/Canada … DRIs are used for planning/assessing diets |
EAR | Estimated average requirement |
RDA | recommended dietary allowance |
AI | adequate intake. appears sufficient to maintain a specified criterion based on scientific judgment Used when RDA cannot be set due to lack of scientific evidence |
UL | tolerable upper level intake. of a nutrient that appears safe for most healthy people Beyond UL there is increased health risk |
Malnutrition | any condition caused by deficient or excess food energy or nutrient intake or by a nutrient imbalance |
Undernutrition | deficient energy/nutrients |
Overnutrition | excess energy/nutrients |
Adequacy | Sufficient nutrients, fiber, energy for health |
Balance | Providing foods in right proportions to each other and body’s needs |
Calorie Control | Management of energy intake |
Nutrient Density | Nutrients provided relative to energy provided. More nutrients & fewer kcals = higher nutrient density |
Moderation | Enough but not too much of a substance |
Variety | Eating foods within/ among food groups |
Nutrient Dense | Term used to denote foods with higher quantity of nutrients (nutrient density) relative to the energy (kcals) provided |
Empty Calorie | Popular term used to denote foods that contribute energy but lack protein, vitamins, and minerals |
Aim for fitness | Aim for a healthy weight. Be physically active each day |
overweight | 10 – 20% > target healthy body weight |
underweight | 10 - 20% < target healthy body weight |
severely overweight | 20 - 30% > target healthy body weight |
Severely underweight | 20 - 30% < target healthy body weight |
Obese | >30 % > target healthy body weight |
Build a healthy base | Let the Pyramid guide food choices, Choose a variety of grains daily, especially whole grains 6. Choose a variety of fruits/vegetables daily 7. Keep foods safe to eat |
Choose sensibly | Choose a diet low in saturated fat and cholesterol and moderate in total fat, Choose beverages/foods to moderate sugar intake, Choose/prepare foods with less salt, If you drink alcohol, do so in moderation |
Mypyramid | Allows for an individualized approach to improving diet and lifestyle |
Grain intake | Eat at least 3 oz. of whole grain cereal, bread, crackers, rice, or pasta daily. 6 oz. Make half your grains whole |
Vegetable intake | Vary your veggies. Eat more dark-green veggies like broccoli, spinach, etc. Eat more orange vegetables like carrots and sweet potatoes Eat more dry beans and peas like pinto beans, kidney beans, and lentils. 2 1/2 cups. |
Fruit Intake | Focus on fruits. Eat a variety of fruit Choose fresh, frozen, canned, or dried Go easy on fruit juices. 2 cups |
Milk Intake | Go low/fat-free when choosing milk, yogurt, and other milk products If you don’t or can’t consume milk, choose lactose-free products or calcium fortified foods/beverages. 3 cups. get your calcium rich foods. |
Meat and beans Intake | Choose low-fat/lean meats/poultry Bake it, broil it, or grill it Vary your protein – choose more fish, beans, peas, nuts, and seeds. 5 1/2 oz. Go lean with protein |
Fat intake | Make most fat sources fish/nuts/veg oils Limit solid fats as well as foods that contain these Check the Nutrition Facts label to keep saturated/trans fats, and sodium low Choose food/beverages low in sugars |
Cereal grain | Husk (chaff) – inedible grain part Bran – outer coat, rich in vitamins, minerals, and fiber Endosperm – major portion of grain, rich in starch and protein Germ – seed that grows into plant, rich in vitamins and minerals |
refinement | Process in which intact grains are refined (broken apart) into components |
Wheat to flour | Bran, germ, and husk are removed Endosperm remains, Refinement process results in decrease of nutrients, Only the endosperm remains intact |
Enrichment | Addition of nutrients lost during processing so that food meets a specified standard |
Nutrients enriched in grains | Iron Thiamin Riboflavin Niacin Folate/folic acid |
Fortification | Addition of nutrients that may not have been present in the first place or were present in insignificant amounts |
Whole Grain | A grain ground into flour in its entirety (except the husk) |
Ingrident List | Listed in descending order of predominance by weight |
Serving sizes | Set by FDA/Facilitates comparisons among foods |
Nutrition facts | Total calories & calories from fat Total CHO, starch, sugars, and fiber Trans fat required on labels beginning 2006 |
Daily Values | Based on 2000 kcal diet = (% DV) |
Nutrient claims | Must meet FDA definitions Examples: low cholesterol, high fiber,sugar-free |
Health claims | List of health claims can be used on food label = these “A” list health claims provide an established connection between a nutrient & a diseases or health condition Example: Sodium and reduced risk of hypertension |
Digestion | process by which food is broken down into absorbable units |
Absorption | passage of nutrients from GI tract into blood or lymph |
Gastrointestinal tract | Flexible muscular tube from mouth, thru the esophagus, stomach, small intestine, large intestine, rectum, and anus. |
Mouth | Begins digestive process/chews and mixes food with saliva |
Salivary Glands | secrete saliva Saliva contains starch-digestive enzymes (carbohydrases) |
Epiglottis | protects airway from closing during swallowing |
Esophagus | Passageway for food from mouth to stomach |
Bolus | name for food unit after swallowing |
Upper Esophageal Sphincter | Prevents backflow of food from esophagus back into mouth |
Cardiac/Lower Esophageal Sphincter (LES): | prevents backflow of food from stomach back into esophagus |
sphincter | a circular muscle surrounding and able to close a body opening |
Stomach | Major site of protein digestion Adds acid (HCl), enzymes (proteases), and fluid to bolus |
chyme | bolus is churned, mixed, and ground |
HCL function | keeps pH of stomach acidic (pH<2) … acidic pH necessary for protein digestion |
Mucus | Secreted by goblet cells in stomach to protect stomach from HCl’s acidic pH |
Pyloric sphincter | prevents backflow from small intestine back into stomach |
stomach proteases | Function in acidic () stomach pH (pH<2) |
Small Intestine | Small bowel. Secretes enzymes (carbohydrases, proteases, lipases) that digests all energy-yielding nutrients Major site of nutrient carbohydrate and lipid digestion Major site of nutrient absorption into blood stream and lymphatic system. |
Small Intestine sections | Duodenum, Jejunum, Ileum |
Pancreatic juice | contains enzymes (carbohydrases, proteases, lipases) and bicarbonate (strong base that keeps pH of small intestine basic/alkaline) |
Pancreatic duct | conducts pancreatic juice from pancreas to duodenum of small intestine |
Bile duct | conducts bile (emulsifying agent) from gallbladder to duodenum of small intestine. Bile is made in liver and stored in gallbladder. |
Large Intestine | Colon/large bowel. reabsorbs water & minerals from chyme and leaves semi-solid waste composed of fiber, bacteria, and unabsorbed nutrients Passes waste & unabsorbed nutrients like fiber on to rectum for elimination |
Large Intestine sections | Ascending colon, transverse colon, descending colon |
Ileocecal valve | separates small and large intestine … near appendix |
Anus | final sphincter muscle |
Motility | Movement of food through GI tract |
Peristalsis | Wavelike muscle contractions that push contents through GI tract |
Stomach muscles | thickest walls & strongest muscles of all GI tract organs |
Segmentation | periodic squeezing/ contracting or partitioning of the intestine at intervals along its length |
Purposes of segmentation | mix chyme promote close contact with digestive juices & absorptive cells of intestinal wall before contents move along |
Enzymes | Made of protein Facilitate/catalyze chemical reactions Digestive enzymes catalyze hydrolysis reactions: Reactant is split into 2 products, with the addition of water Molecule is broken into smaller pieces “ase” = enzyme |
Hormones | Usually made of protein Act as chemical messengers Regulate enzyme action |
Digestion Secretion Sites | Salivary glands Stomach Pancreas Liver (via Gallbladder) Small intestine |
Gland | A cell/group of cells that secretes materials |
Exocrine Glands | Secrete materials out of the body (into digestive tract or onto skin) |
Endocrine Glands | Secrete materials inside the body (into the blood) |
Where does most absorption of nutrients take place? | Small Intestine (Duodenum and Jejunum) |
Villi | Fingerlike projections from the folds of the small intestine that surface area |
Microvilli | Tiny,hairlike projections on each villus; trap nutrients & transport them into cells |
crypts | Tubular glands that secrete intestinal juices into the small intestine |
Lymphatic System | Loosely organized system of vessels & ducts Conveys fluids toward thorasic duct and then to the vena cava of the heart |
Lymph | clear yellowish fluid almost identical to blood … but containing no RBCs or platelets. |
Homeostasis | maintenance of constant internal conditions by the body’s control systems… maintenance of: Blood sugar/blood chemistry Body temperature Blood pressure, etc |
Hormones | chemical messengers secreted by a variety of glands in response to altered conditions in the body. Each hormone travels to one or more specific target tissues or organs where it elicits a specific response to maintain homeostasis |
Homeostasis def. | the maintenance of constant internal conditions (such as blood pressure/ blood chemistry/temperature) by body control systems. Homeostatic systems constantly react to external forces to maintain limits set by body needs |
Enterogastrones | usually slow GI motility and include: Gastrin Secretin Cholecystokinin Gastric Inhibitory Peptide |
Gastrin | Secreted by stomach wall cells Gastrin secretion turned on by presence of protein in stomach Gastrin secretion turned off when stomach pH reaches 1.5 |
Secretin | The pyloric sphincter opens … chyme (acidic) is released into duodenum (basic) … presence of chyme in small intestine triggers secretion of secretin Secretin produced in duodenal wall cells |
Action of Secretin | Secretion of bicarbonate-rich (basic) pancreatic juice Bicarbonate travels via pancreatic duct to small intestine to neutralize chyme |
Cholecystokinin | Produced when fat is present in small intestine, produced by intestinal wall cells, turned on by presence of fat in intestine, turned off when fat is emulsified (and no longer present) Fat takes longer to digest than carbs and pro |
Cholecystokinin Actions | CCK causes gallbladder to contract and release bile Bile travels via common bile duct to small intestine to emulsify fat CCK also slows gastric motility |
Gastric Inhibitory Peptide | Produced by intestinal wall cells (like CCK) Secretion turned on by presence of fat in intestines Secretion turned off when no more fat is present in intestines |
Gastric Inhibitory Peptide Actions | Slows GI motility Slows gastric secretions |
Bicarbonate | Bicarbonate secretion turned on by presence of chyme in duodenum Bicarbonate secretion turned off by neutral to basic pH in duodenum (neutralizatin of all chyme) |
Bicarbonate actions | Pyloric sphincter opens to let chyme pass into duodenum Presence of chyme in small intestine closes pyloric sphincter Bicarbonate neutralizes chyme |
proteases,lipases, and carbohydrases | are secreted by both the small intestine (duodenum) and pancreas |
proteases,lipases, and carbohydrases actions | Amounts secreted are still under investigation. Research suggests enzymes are secreted in amounts similar to recent diet needs. |
Simple carbohyrdates | Monosaccharides Disaccharides |
Complex carbohyrates | Polysaccharides (Starch), Fiber, Glycogen |
Monosaccharides | Glucose Fructose Galactose |
Hydrogen bonds | form 1 bond |
Oxygen bonds | form 2 bonds |
Nitrogen bonds | form 3 bonds |
Carbon bonds | form 4 bonds |
Glucose | Not very sweet One of two sugars in all three disaccharides Also known as dextrose or blood sugar Essential energy source (fuel) for all of the body’s functions |
Fructose | Sweetest sugar Is a component of sucrose Also known as levulose or “fruit sugar” … still a hexose Sources: honey, fruits, & high fructose corn syrup |
Galactose | Not sweet Seldom found ‘free’ in nature Usually bound with glucose to form lactose |
Disaccharides | Pairs of monosaccharides Glucose a component all three Formed by condensation reactions Broken apart by hydrolysis reactions |
Disaccharides Types | maltose (glucose + glucose = maltose) sucrose (glucose + fructose = sucrose) lactose (glucose + galactose = lactose) |
Condensation reactions | Reactions in which two reactants combine to form a larger product, Hydroxyl group (-OH) from one monosaccharide combines with hydrogen atom (-H) from another monosaccharide to form a disaccharide, Water (H2O) is formed Synthesis reaction |
Hydrolysis reactions | Reactions when molecule is split in two, are the major in the process of digest, molecule is split, a h atom from water is added to one(monosaccharide)and a hydroxyl group (-OH) is added, opposite of a condensation reaction Water is required |
Sucrose | Glucose + fructose condense to form sucrose Table sugar, powdered sugar, brown sugar, syrups:made from sugarcane & sugar beets Hydrolyzed (broken apart) by sucrase (enzyme) Enzymes usually end in -ase |
Lactose | Galactose + glucose condense to form lactose “Milk sugar” Broken down by lactase |
Lactose Intolerance | does not make lactase and have trouble digesting (hydrolyzing) lactose in dairy foods. |
Lactase defieciency | Lack of lactase enzyme |
Milk allergy | Immune reaction to protein (casein) in milk |
Lactose Intolerance symptoms | lactose in small intestine remains undigested, Undigested disaccharide attracts water. Causes bloating, diarrhea, abdominal discomfort |
Maltose | glucose + glucose condense to form maltose Intermediate product of starch breakdown Found in germinating seeds (bean sprouts/ alfalfa sprouts) and as malt Substrate for fermentation process that yields alcohol in some beverages and breadmaking |
POLYSACCHARIDE | Many glucose units condense together |
POLYSACCHARIDE types | Glycogen Starch Fiber |
Starch | Plant polysaccharide composed of hundreds/thousands of glucose molecules Storage form of energy (glucose) in plants Long branched/unbranched glucose chains Major food energy source in diets throughout the world |
Glycogen | Animal polysaccharide composed of glucose molecules Storage form (finite) of carbohydrate found in muscles & liver (1200-1400 kcals) Not significant food source of CHO Highly branched chains lead to rapid hydrolysis |
Fiber | Found only in plant foods. Polysaccharide not digestible, although some are digested by GI tract bacteria. Includes pectins, cellulose, hemicelluloses,gums,and mucilages. Some fibers are non-polysaccharides. Provide GI and cardiovascular benefits |
Insoluble Fiber | Not water soluble Non-viscous Not readily fermentable by GI bacteria |
Insoluble Fiber benefits | Prevents/alleviates constipation. Increases stool volume/weight. Provides feeling of fullness. Useful in weight management. Reduces risk of diverticulosis,hemorrhoids, appendicitis. Reduces risk of colon cancer |
Insoluble fiber food sources | Wheat bran, whole grains, brown rice, fruits. vegetables |
Phytic Acid | Nonnutrient found in grain husks, legumes, seeds Capable of binding minerals excreted by the body |
Salivary amylase | begins starch digestion in mouth |
Digestion compounds: small intestine | Maltase, sucrase, lactase Hydrolyze disaccharides |
Digestion compounds: Pancreas | Pancreatic amylase Secreted into small intestine; digests remaining starch to individual monosaccharide units (glucose) |
Digestion compounds: Large Intestine | Viscous fibers Fermented into water, gas, short chain FAs Fibers hold water, regulate bowel activity, cause excretion of bound bile, cholesterol, and some minerals |
Gluconeogenesis | Synthesis of glucose from non-carbohydrate sources (protein or fat) |
Gluconeogenic body protein | 50% can be converted to glucose |
Gluconeogenic fat | 5% can be converted to glucose |
Protein sparing action | The action/role of carbohydrate (and fat) in providing energy so that protein is spared for other purposes |
Ketone bodies | The product of the incomplete breakdown of fat that occurs in gluconeogenesis … when glucose is not available in the cells |
ketosis | Fat fragments combine into ketone bodies, accumulate in the blood and cause the blood to become acidic |
Insulin | lowers blood glucose, a hormone secreted by the beta cells of the pancreas, is secreted by the pancreas in response to increased [glucose] Primary role is to control the transport of glucose from the blood stream into muscle and fat cells |
Glucagon | raises blood glucose, a hormone secreted by the alpha cells of the pancreas, is secreted by the pancreas in response to low [glucose] Primary role is to cause the release of glucose from liver glycogen stores |
Epinephrine (adrenaline) | raises blood glucose quickly, fight or flight, When a person experiences stress. acts is released, acts quickly to cause the liver to release glucose from stores into the bloodstream to ensure that all body cells have an energy fuel in emergencies |
emia | Suffix than means … “in the blood” |
uria | Suffix that means … “in the urine” |
hyper | Prefix that means … “an elevated concentration of” |
hypo | Prefix that means … “too low a concentration of” or “an abnormally low concentration of” |
normo | Prefix that means … “a normal concentration of” |
normoglycemia | (fasting) is 70-110 mg/dl glucose |
Type 1 | Insulin Dependent Diabetes Mellitus Juvenile Onset |
Type 2 | Non-insulin Dependent Diabetes Mellitus Adult Onset |
Gestastional | Diabetes during Pregnancy |
Symptoms of diabetes | Hyperglycemia Polydypsia Polyuria Polyphagia Glucosuria Abnormal fasting [glucose] Abnormal GTT Abnormal 2-hour post-prandial [glucose] Elevated glycosylated hemoglobin A1C |
Diabetic diet | 58% carbohydrate < 30% fat 12% protein |
Complications of diabetes | Retinopathy Neuropathy Nephropathy CVD |
glycemic index | Method of classifying foods according to their potential for raising [glucose] |
glycemic effect | The effect of food on [glucose] compared to a standard (glucose) |
glycemic response | The extent to which a food raises [glucose] and elicits an insulin response |
Health effects of sugars | Dental caries (tooth decay) Nutrient deficiencies … by supplying kcals of energy without providing nutrients Sugar is a common food additive and goes by many names |
Health effects of starch and fiber | Decreased risk of heart disease Decreased risk of diabetes GI health Decreased risk of colon cancer Weight management |
Phenylketonuria | Genetically inherited disease. No enzyme is produced, no tyrosine is produced, [phenylalanine] builds up |
Roles of Fat in the body | Chief form of stored energy Especially during periods of fasting/starvation, Provide energy for muscular work, Major component of cell membranes, Protects internal organs against trauma/shock, Provides raw materials for synthesis of many compounds |
Roles of Fat in the diet | Source of concentrated energy, Carrier of fat soluble vitamins & aid in their absorption, Provide essential fatty acids, Contribute to the palatability of foods, Taste & Smell, Slows digestive processes, Contributes satiety |
Fatty Acids | Organic compounds, Composed of C chains with - H attached, Acid group (carboxyl group) (COOH) attached at one end of the C chain, Methyl group (-CH3) attached at the other end of the C chain |
Chemical Structure of Lipids | Fatty Acids |
Stearic Acid | 18-carbon, saturated |
Oleic Acid | 18-carbon, monounsaturated |
Linoleic Acid | 18 C polyunsaturated FA |
Omega Nomenclature | it is possible to identify the position of the first C=C relative to the methyl end of the FA |
omega carbon atom | carbon atom in the methyl group (-CH3) at one end of the FA |
omega number | the position of the first C=C (carbon to carbon double bond) relative to the methyl end |
Why are carbons in even numbers? | FAs are hydrolyzed in digestion, they are boken apart into 2-C segments |
Long-Chain Fatty Acids | 12-24 C Meat & fish Olive oil |
Medium Chain Fatty Acids | 6-10 C Cocoa butter & palm oil |
Short Chain Fatty Acids | <6 C Dairy products |
Saturated Fatty Acids | Fully loaded with H No C=C Butter, lard, & palm & coconut oils |
Polyunsaturated Fatty Acids | 2 or more C=C Linoleic acid (18 C w/2 C=C) Linolenic acid (18 C w/3 C=C) Vegetable oils |
monounsaturated fatty acids | 1 C=C Oleic acid (18 C w/1 C=C) Olive/olive oil, canola oil & peanuts/peanut oils |
Point of unsaturation | double bonds |
Amount triglycerides in foods | 95% in lipids |
Amount triglycerides in body | 99% in lipids |
Triglyceride | Condensation of Glycerol & Fatty Acids H from glycerol molecule and hydroxyl group (-OH) from FA H2O (by-product) |
Hydrogenation | a chemical process by which hydrogens are added to monounsaturated or polyunsaturated FAs to reduce the number of double bonds, making the fat more saturated (solid) and more resistant to oxidation (protecting against rancidity) |
Advantages of hydrogenation | Protect against oxidation (extend shelf life) Change texture |
Disadvantages of hydrog |