CHAPTER ONEI. What is nutrition?A. overview1. definition: the science of the nutrients in foods and their actions within the body; can include the study of human behaviors related to food and eating a. ingestion/digestionb. absorption c. transportd. metabolism: how the body uses food e. excretion 1.1. FOOD CHOICES A. activity 1. for the health benefitsa. functional foods (designer foods and nutraceuticals)- foods that contain bioactive components that provide health benefits beyond their nutrient contributions - ex: whole foods (natural and familiar), modified foods (modified to provide health benefits, such as lowering fat content) and fortified food (by adding nutrients or phytochemicals)b. phytochemicals - nonnutrient compounds found in plants. Some phytochemicals have biological activity in body (fight cancer, infections, reduce inflammation).phyto = plant 2. food choices ** influence health, the balance of choices selected over time can make important difference to health, think “nutrition” when making choices**a. preferencesb. habit (always have cereal for breakfast..)c. ethnic heritage and regional cuisines d. social interactionse. availability, convenience, and economyf. positive and negative associationsg. emotionsh. values (religion, vegetarian)i. body weight and imagej. nutrients and health benefits1.2 NUTRIENTS A. nutrients and food in the body1. obtained from food and used in body to:a. for energyb. structural materialsc. regulating agents (hormones and enzymes)d. support growth, maintenance, and repairs of the body’s tissuese. also reduce the risks of some diseasesB. six nutrients1. organic (a substance or molecule containing carbon-carbon bonds or carbon-hydrogen bonds. This definition excludes coal, diamonds, and a few carbon-containingcompounds that contain only a single carbon and no hydrogen, (ex: carbon dioxide); all contain carbon, hydrogen, and oxygen)a. carbohydrates (COH)b. proteins (COH and nitrogen) c. lipids (COH)d. vitamins (COH)2. inorganic (not containing carbon or pertaining to living things)a. water (hydrogen and oxygen)b. minerals (simplest nutrient)-simplest of the nutrients are the minerals- a chemical element; atoms are all alike; identity never changesC. nutrient composition of the body1. 60-70% of us is water – depending on stature D. macronutrients vs micronutrients1. macronutrients – body requires them in large amounts (grams/day)a. needs more macro then microb. CHO, PRO, FAT2. micronutrients- required in small amounrs (mg/d)a. vitamins/mineralsE. essential nutrients (indispensable)1. body cannot make them2. makes insufficient quanitities to meet needs3. must be obtained from foods4. about 40 knownF. energy yielding nutrients: carbs, fat, and protein 1. overviewa. amount of energy/calories in food- depends on macronutrient compositionb. using nutrients for fuel (energy)- supports every activity c. These nutrients will give your body calories/energyd. only way we can get calories: CHO, PRO, and fats (and alcohol which is not a nutrient)2. energy-yielding nutrients *****KNOW NUMBERS*****a. provides kcalories (energy)- carbohydrates = 4 kcal/one gram- protein = 4 kcal/one gram- fat = 9 kcal/one gramb. alcohol- not a nutrient- yields energy 7 kcal/gc. kcal for one thing / total kcal = % of energy3. activity a. 1 slice of bread w/ 1 T. peanut butterb. contains 16g CHO, 7g PRO, and 9g FAT- calculate energy available- calculate % for kcal fat contributes to total16g CHO x 4 kcal/g from CHO = 64 kcal7g PRO x 4kcal/g from PRO = 28 kcal9g FAT x 9kcal/g from FAT = 81 kcalTotal = 173 kcal To find % of kcal from energy nutrients: kcal/total kcal x 10081 fat kcal/ 173 kcal = .468 (round .47).47 x 100 = 47%G. energy density1. example – which is more dense?a. calories/weight = energy density!b. lower energy density means its more healthy; fills you up more; more food for the calories c. higher energy density: weighs less; more dense ** non-energy yielding nutrients (no calories = no energy) : vitamins, minerals, and water H. the vitamins1. thirteen organic vitaminsa. water soluble vitaminsb. fat-soluble vitamins2. facilitate energy release from CHO, PRO, FATa. DO NOT PROVIDE ENERGYb. almost every bodily action requires assistance from vitamins3. vulnerable to destruction from heat, light, chemicals4. Basically calorie free5. Helps get the energy out of CHO PRO and FATI. the minerals and water1. mineralsa. DO NOT PROVIDE ENERGYb. sixteen essential vitaminsc. indestructible, inorganic- can be lost during refining or cooking- bound to substances that interfere with body’s ability to absorb them2. water ***a. medium for nearly all body activities b. DOES NOT PROVIDE ENERGY (1.3) THE SCIENCE OF NUTRITION A. overview1. the study of nutrients and other substances in food and the body’s handling of them2. foundation in several other sciences a. biology, biochemistry, physiology 3. where do consumers get nutritional information?a. personal experience, reports from friendsb. not acceptable, reliable scientific information= anecdoteB. types of research1. epidemiological studiesa. determine incidence and distribution of disease in a population - b. Studies of large populationsc. i.e. = mediterranenans have a lower incidence of heart disease due to high intake of MUFAd. incidence – measure of the risk of developing some condition within a specificperiod of time 2. experimental studiesa. explorer effects of specific variable on a tissue, cell, or molecule b. Test something; c. Ex: effect of creatine supplementation on muscle mass of collegiate wrestlersd. how we determine nutritional science C. research1. termsa. control groupb. dependent variablec. randomizationd. sample sizee. placebosf. double-blind or blind experimentsg. experimental grouph. independent variable 2. analyzing research findings- correlationsa. only prove associationb. no cause/effect relationshipc. cautious interpretations and conclusionsd. “may” “some”- accumulation of evidence = gain confidence in making recommendations3. types of correlationsa. positive correlation (more OJ consumed, more colds; both variable change in the same direction; not necessarily a desired outcomeb. negative correlation (less OJ consumed, more colds; variables change in opposite directions)c. no correlation (no change; regardless amount of vitamin C = cold stayed same)4. publishing researcha. peer review- research has validity b. findings are preliminary when published- not meaningful by
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