CHAPTER 1 THE SCIENCE OF NUTRITION

WHAT IS NUTRITION? Nutrition is the “science of food, the nutrients and substances therein; their action, interaction, and balance in relation to health and disease; and the process by which the organism (human) ingests, digests, absorbs, transports, utilizes, and excretes food substances.” 2

NUTRIENTS Macronutrients Carbohydrates Proteins Lipids Water Micronutrients Vitamins Minerals 3

FUNCTIONAL CATEGORIES OF NUTRIENTS 4

CARBOHYDRATES Composed of the elements Carbon, Hydrogen and Oxygen Simple carbohydrates Fruit, Sugar, Glucose Complex carbohydrates Grains, Glycogen Provides 4 kcal/gram 5

LIPIDS Composed of the elements Carbon, Hydrogen and Oxygen Triglycerides-major form of fat in food Saturated fatty acids Unsaturated fatty acids Trans fatty acids Essential fatty acids Linoleic acid Alpha-linolenic acid Provide 9 kcal/gram (fewer oxygen atoms) 6

PROTEIN Composed of the elements Carbon, hydrogen, oxygen and nitrogen Functions Component of bone, muscle, enzymes, immune function, blood and cell membranes Formed by combining amino acids Provides 4 kcal/gram 7

VITAMINS ENABLE CHEMICAL REACTIONS Water soluble Vitamins C and B complex More easily excreted from the body Easily destroyed by cooking Fat soluble Vitamins A, D, E and K More easily stored in the body Greater risk for toxicity 8

MINERALS ORGANIC COMPOUNDS REQUIRED FOR BODY FUNCTIONS Major Minerals Required in gram amounts Sodium, Potassium, Chloride, Calcium and Phosphorus Trace Minerals Required less than 100 mg daily Iron, Zinc, Copper and Selenium 9

WATER Macronutrient required in largest quantity Sources Beverages, foods and metabolism Functions Lubricant, solvent, transportation medium and regulates body temperature 10

PHYTOCHEMICALS AND ZOOCHEMICALS Physiologically active compounds that provide benefits but are not essential nutrients Phytochemicals Plant (flavonoids) Zoochemicals Animal (omega 3 fatty acid) 11

SUPPLEMENT VS. FOOD Glucoraphanin, gluconasturtiian, and glucobrassicin-activates, neutralizes, and eliminates contaminants Isothiocyanates -detox-regulating molecules Kaempferol - anti-inflammatory Protein, Vitamin E, Thiamin, Riboflavin, Pantothenic Acid, Calcium, Iron, Magnesium, Phosphorus and Selenium, Fiber, Vitamin A, Vitamin C, Vitamin K, Vitamin B6, Folate, Potassium and Manganese 12

ENERGY SOURCES Kilocalorie is the amount of heat energy it takes to raise temperature of 1000 grams of water 1° C Carbohydrates 4 kcal/gram Protein 4 kcal/gram Lipids 9 kcal/gram Alcohol 7 kcal/gram 13

14 WHY DO WE EAT?

WHAT DOES THE AVERAGE AMERICAN EAT? 15

16 Sugar Starch Animal fat Plant fat Animal PRO Plant PRO WHAT DOES THE AVERAGE AMERICAN EAT?

NUTRITIONAL HEALTH STATUS Desirable Nutritional Status Under nutrition Subclinical deficiency Clinical deficiency Over nutrition Toxicities Excesses of energy nutrients-obesity 17

NUTRITIONAL ASSESSMENT Anthropometrics Biochemical Clinical Dietary Environmental 18

GENETICS AND NUTRITION Lifestyle, diet and genetics influence disease risk Genetic mutations increase risk for some diseases Genetic testing 19

20

NUTRITIONAL SUPPLEMENTS 1994 DSHEA (Dietary Supplement Health and Education Act) Supplements do not require FDA approval Do not need to be proven safe 21

REAL OR QUACK?

EVALUATING NUTRITION CLAIMS AND PRODUCTS Scientifically sound Dubious nutrition claims Scientific credentials of author Examine the study Beware of hype- if it sounds too good to be true…it is. 23

RELIABLE NUTRITION ADVICE Registered Dietitian (RD)-United States 24