Introduction to Basic Nutrition Concepts

Introduction to Basic Nutrition Concepts

Nutrients—Essential vs Nonessential • Nutrient: Chemical substance in food that contributes to health • Essential nutrient: Needed by the body and must come from diet because of absent or inadequate synthesis • When left out of the diet, results in poor health • Examples: Vitamin A, iron, tryptophan, linoleic acid • Nonessential nutrient: No specific dietary requirement • Examples: Cholesterol, beta-carotene (pre-vitamin A), alanine, palmitic acid • May have physiological functions in the body, but dietary supply is not needed because of the body’s ability to synthesize sufficient amounts • In the case of vitamin A, beta-carotene is not required if there is retinol (already formed vitamin A) in the diet • Conditional essentiality: Nutrient may be essential in the diet under certain circumstances • Example: Vitamin D in those without adequate sun exposure

The 6 Major Classes of Nutrients • Water • Carbohydrate • Fats/lipids • Protein • Vitamins • Minerals • Macronutrients provide energy (kcals, or nutritional/food calories), but micronutrients do not • Note: Ethanol provides energy, but is not considered a nutrient Macronutrients (needed in larger amounts) Micronutrients (needed in smaller amounts) Abbreviation: kcal, kilocalorie (1 food or nutritional calorie = 1,000 energy or scientific calories).

Dietary Carbohydrates • Sugars • Monosaccharides (glucose, galactose, fructose) • Disaccharides • Sucrose: glucose + fructose • Lactose: glucose + galactose • Maltose: glucose + glucose • Starches (polymer, or chain, of many glucose units) • Dietary fibers

Glycogen • Glycogen is carbohydrate stored as glucose polymers in muscle • Average, well-nourished 80-kg man stores ~500 g of carbohydrate in the body • 90 to 110 g as glycogen in the liver (can be broken down to glucose for use as fuel throughout the body) • 400 g as glycogen in muscles (for use as fuel only by muscles) • 2 to 3 g as circulating blood glucose • Glycogen stores can be modified with diet and exercise (eg, carbohydrate loading, tapering of training) Abbreviations: g, grams; kg, kilograms.

Dietary Lipids (Fats) • Triglycerides (glycerol + fatty acids) • Fatty acids • Saturated • Monounsaturated • Polyunsaturated (essential fatty acids, linoleic and linolenic acids) • Omega-3, omega-6 • Trans • Main fatty acids in diet are typically 12 carbon atoms or longer • Medium-chain triglycerides contain fatty acids primarily in the 8 to 10 carbon atom range • Cholesterol • Phospholipids

Protein • Proteins are chains of amino acids (~20 total in food) • 9 essential amino acids in human nutrition • Other amino acids (eg, alanine) can be made in the body • Sometimes an amino acid can become conditionally essential, depending on disease or stress to the body

Vitamins • Fat-soluble • Vitamins A, D, E, and K • Water-soluble

Minerals

Measurement Units in Nutrition • 1 kcal = heat energy needed to raise the temperature of 1 kg of water by 1 degree Celsius (bomb calorimeter) • Nutritional calorie (Calorie), or kcal, is equivalent to 1,000 scientific (energy) calories • Note difference between capital and small letter c • When we casually say a slice of bread has 70 Calories, we really mean 70 kcal, or 70 nutritional calories Abbreviations: cm, centimeter; dL, deciliter; fl, fluid; g, gram; kcal, kilocalories (1 food or nutritional calorie = 1,000 energy or scientific calories); kg, kilogram; kjoule, kilojoule; L, liter; lb, pound; µg, microgram; mg, milligram; mL, milliliter; oz, ounce; T, tablespoon; tsp, teaspoon.

Energy Constants for Macronutrients • Carbohydrate (general): 4 kcal/g • Dietary fibers typically between 0 to 2 kcal/g (depends on fermentability by gut bacteria) • Protein (general): 4 kcal/g • Fat (general): 9 kcal/g • Medium-chain triglyceride oil: 8.3 to 8.5 kcal/g • Ethanol: 7 kcal/g Abbreviations: g, gram; kcal, kilocalorie (1 food or nutritional calorie = 1,000 energy or scientific calories).

Calculating Kilocalories for a Granola Bar Abbreviations: g, gram; kcal, kilocalorie (1 food or nutritional calorie = 1,000 energy or scientific calories).

General Nutrition Guidelines

U.S. Institute of Medicine Dietary Reference Intakes • Estimated Average Requirement (EAR) • Level of nutrient intake at which 50% of population would be deficient • Recommended Dietary Allowance (RDA) • Level of intake that would meet the nutrient needs of practically all healthy persons • Adequate Intake (AI) • Similar to RDA, but for nutrients for which there is not specific enough information to determine an RDA • Tolerable Upper Intake Level (UL) • Level of intake which, if exceeded on a chronic basis, increases the risk of toxicity or adverse health effects • Acceptable Macronutrient Distribution Range (AMDR) • Guidelines for healthy percentages of kcals from carbohydrates, proteins, and fats in the diet • See supplementary slides for Dietary Reference Intake (DRI) tables for each nutrient

Daily Values for Food Labels • Food labels list the nutrient content as a percentage of the Daily Value • Two categories of Daily Values • Reference Daily Intake • For vitamins and minerals • Based on RDAs from 1968 • Daily Reference Values • For nutrients such as cholesterol or fiber that did not have RDAs in 1968 • Based on recommendations from various health organizations or a certain percentage of energy on a 2,000 or 2,500 kcal diet Abbreviations: kcal, kilocalorie (1 food or nutritional calorie = 1,000 energy or scientific calories); RDA, recommended dietary allowance; RDI, reference daily intake.

Nutrition Facts Reprinted from Center for Young Women’s Health, Children’s Hospital Boston: http://www.youngwomenshealth.org/nutrition_label.html.

USDA My Plate Reprinted from US Department of Agriculture at: http://www.ChooseMyPlate.gov.

Tools at ChooseMyPlate.gov • Descriptions of each of the food groups • Brochure on getting started with My Plate • Images of My Plate • Individual food group plan based on your personal height, weight, age, and activity level • 10 Tips Nutrition Education Series • Information for specific populations • General population • Pregnancy and breastfeading • Preschoolers • Kids • Weight loss • Other information associated with My Pyramid can be found there (e.g., sample 2000 kcal meal plans, images, etc.) Abbreviations: kcal, kilocalorie (1 food or nutritional calorie = 1,000 energy or scientific calories).

Regulation of Dietetic Practice in the US

Understanding the Scope of the Practice of Dietetics • The American Dietetic Association is the professional organization for dietitians • Commission on Dietetic Registration regulates the term Registered Dietitian (RD) • “Nutritionist” is a generally unregulated term • 44 states plus the District of Columbia and Puerto Rico require licensure/certification/registration of dietitians or nutritionists • Licensure is the most stringent of these requirements • In a state with licensure, one cannot practice dietetics without a license from the state board • In states with licensure, most Licensed Dietitians (LD) are RDs • Be aware of the laws in your state (http://www.cdrnet.org) • Web site has links to state licensure boards/agencies • From state to state, there are differences in what constitutes the practice of dietetics

Appropriate Counseling and Referral • Be aware of potential nutrition issues (eg, eating disorders) • Maintain access to a qualified RD for nutritional issues that might require higher level of nutritional or medical expertise • To find a sports-oriented RD, go to • http://www.eatright.org • http://www.scandpg.org Abbreviation: RD, Registered Dietician.

Supplementary Slides

Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Vitamins Food and Nutrition Board, Institute of Medicine, National Academies NOTE: This table (taken from the DRI reports, see www.nap.edu) presents Recommended Daily Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type followed by an asterisk (*). RDAs and AIS may both be used as goals for individual intake. RDAs are set to meet the needs of almost all (97 to 98 percent) individuals in a group. The AI for life stage and gender groups is believed to cover needs of all individuals in the group, but lack of data or uncertainty in the data prevent being able to specify with confidence the percentage of individuals covered by this intake. a As retinol activity equivalents (RAEs). 1 RAE = 1 µg retinol, 12 µg b-carotene, 24 µg a-carotene, or 24 µg b-cryptoxanthin. The RAE for dietary provitamin A carotenoids is twofold greater than retinol equivalents (RE), whereas the RAE for preformed vitamin A is the same as RE. b As cholecalciferol, 1 µg cholecalciferol = 40 IU vitamin D. c In the absence of adequate exposure to sunlight. d As a-tocopherol. a-Tocopherol includes RRR-a-tocopherol, the only form of a-tocopherol that occurs naturally in foods, and the 2R-sterioisomeric form of a-tocopherol (RRR-, RSR-, RRS-, and RSS-a-tocopherol) that occur in fortified foods and supplements. It does not include the 2S-stereoisomeric forms of a-tocopherol (SRR-, SSR-, SRS-, and SSS-a-tocopherol), also found in fortified foods and supplements. e As niacin equivalents (NE). 1 mg of niacin = 60 mg of tryptophan; 0-6 months = preformed niacin (not NE). f As dietary folate equivalents (DFE). 1 DFE = 1 µg food folate = 0.6 µg of folic acid from fortified food or as a supplement consumed with food = 0.5 µg of a supplement taken on an empty stomach. g Although AIs have been set for choline, there are few data to assess whether a dietary supply of choline is needed at all stages of the life cycle, and it may be that the choline requirement can be met by endogenous synthesis at some of these stages. h Because 10 to 30 percent of older people may malabsorb food-bound B12, it is advisable for those older than 50 years to meet their RDA mainly by consuming foods fortified with B12 or a supplement containing B12. Adapted from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:532-533.

Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Vitamins (continued) Food and Nutrition Board, Institute of Medicine, National Academies NOTE: This table (taken from the DRI reports, see www.nap.edu) presents Recommended Daily Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type followed by an asterisk (*). RDAs and AIS may both be used as goals for individual intake. RDAs are set to meet the needs of almost all (97 to 98 percent) individuals in a group. The AI for life stage and gender groups is believed to cover needs of all individuals in the group, but lack of data or uncertainty in the data prevent being able to specify with confidence the percentage of individuals covered by this intake. a As retinol activity equivalents (RAEs). 1 RAE = 1 µg retinol, 12 µg b-carotene, 24 µg a-carotene, or 24 µg b-cryptoxanthin. The RAE for dietary provitamin A carotenoids is twofold greater than retinol equivalents (RE), whereas the RAE for preformed vitamin A is the same as RE. b As cholecalciferol, 1 µg cholecalciferol = 40 IU vitamin D. c In the absence of adequate exposure to sunlight. d As a-tocopherol. a-Tocopherol includes RRR-a-tocopherol, the only form of a-tocopherol that occurs naturally in foods, and the 2R-sterioisomeric form of a-tocopherol (RRR-, RSR-, RRS-, and RSS-a-tocopherol) that occur in fortified foods and supplements. It does not include the 2S-stereoisomeric forms of a-tocopherol (SRR-, SSR-, SRS-, and SSS-a-tocopherol), also found in fortified foods and supplements. e As niacin equivalents (NE). 1 mg of niacin = 60 mg of tryptophan; 0-6 months = preformed niacin (not NE). f As dietary folate equivalents (DFE). 1 DFE = 1 µg food folate = 0.6 µg of folic acid from fortified food or as a supplement consumed with food = 0.5 µg of a supplement taken on an empty stomach. g Although AIs have been set for choline, there are few data to assess whether a dietary supply of choline is needed at all stages of the life cycle, and it may be that the choline requirement can be met by endogenous synthesis at some of these stages. h Because 10 to 30 percent of older people may malabsorb food-bound B12, it is advisable for those older than 50 years to meet their RDA mainly by consuming foods fortified with B12 or a supplement containing B12. i In view of evidence linking folate intake with neural tube defects in the fetus, it is recommended that all women capable of becoming pregnant consume 400 µg from supplements or fortified foods in addition to intake of food folate from a varied diet. j It is assumed that women will continue consuming 400 µg from supplements or fortified food until their pregnancy is confirmed and they enter prenatal care, which ordinarily occurs after the end of the periconceptional period—the critical time for formation of the neural tube. Adapted from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:532-533.

Dietary Reference Intakes (DRIs):Tolerable Upper Intake Levels (ULa), Vitamins a UL = The maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. Unless otherwise specified, the UL represents total intake from food, water, and supplements. In the absence of ULs, extra caution may be warranted in consuming levels above recommended intakes. b As preformed vitamin A only. c As α-tocopherol; applies to any form of supplemental α-tocopherol. d The ULs for vitamin E, niacin, and folate apply to synthetic forms obtained from supplements, fortified foods, or a combination of the two. SOURCES: Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride (1997); Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998); Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000); and Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. (2001). These reports may be accessed via http://www.nap.edu. Adapted from Manore M, et al. Sport Nutrition for Health and Performance, 2nd ed. Champaign IL: Human Kinetics, 2009. With permission from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:538-539.

Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Elements Food and Nutrition Board, Institute of Medicine, National Academies NOTE: This table presents Recommended Daily Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type followed by an asterisk (*). RDAs and AIs may both be used as goals for individual intake. RDAs are set to meet the needs of almost all (97 to 98 percent) individuals in a group. The AI for life stage and gender groups is believed to cover needs of all individuals in the group, but lack of data or uncertainty in the data prevent being able to specify with confidence the percentage of individuals covered by this intake. SOURCES: Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride (1997); Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998); Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000); Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. (2001); and Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2004). These reports may be accessed via http://www.nap.edu. Adapted from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:534-535.

Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Elements (continued) Food and Nutrition Board, Institute of Medicine, National Academies NOTE: This table presents Recommended Daily Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type followed by an asterisk (*). RDAs and AIs may both be used as goals for individual intake. RDAs are set to meet the needs of almost all (97 to 98 percent) individuals in a group. The AI for life stage and gender groups is believed to cover needs of all individuals in the group, but lack of data or uncertainty in the data prevent being able to specify with confidence the percentage of individuals covered by this intake. SOURCES: Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride (1997); Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998); Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000); Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. (2001); and Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2004). These reports may be accessed via http://www.nap.edu. Adapted from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:534-535.

Dietary Reference Intakes (DRIs):Tolerable Upper Intake Levels (ULa), Elements a UL = The maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. Unless otherwise specified, the UL represents total intake from food, water, and supplements. In the absence of ULs, extra caution may be warranted in consuming levels above recommended intakes. b The ULs for magnesium represent intake from a pharmacological agent only and do not include intake from food and water. SOURCES: Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride (1997); Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998); Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000); and Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. (2001); and Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2004). These reports may be accessed via http://www.nap.edu. Adapted from Manore M, et al. Sport Nutrition for Health and Performance, 2nd ed. Champaign IL: Human Kinetics, 2009. With permission from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:540-541.

Acceptable Macronutrient Distribution Range a Approximately 10% of the total can come from longer-chain n-3 or n-6 fatty acids. Abbreviations: y, years of age.Adapted from Institute of Medicine of the National Academies. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC; National Academies Press; 2006:537.

Introduction to Basic Nutrition Concepts