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Kinesiology 110. Human Nutrition : Current Issues Instructor : Ryan Dill email ryand@sfu.ca 778-782-7851 (Vancouver) Office HC 2622 (ring doorbell at 2600) Office hours : Mondays 3-4 pm Also by appointment through email. Course Tools. Course Web Site www.sfu.ca/~ryand/kin110.htm
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Kinesiology 110 Human Nutrition : Current Issues Instructor : Ryan Dill email ryand@sfu.ca 778-782-7851 (Vancouver) Office HC 2622 (ring doorbell at 2600) Office hours : Mondays 3-4 pm Also by appointment through email
Course Tools • Course Web Site • www.sfu.ca/~ryand/kin110.htm • Course outline • Grading system • Download Assignments • Lecture Schedule • Download Course notes • Link to web site for Text book • Multiple choice quizzes • Nutrition Crossword puzzles • Animation tools
Nutrients and Nourishment Chapter 1 Chapter 2 p 31-72 Appendix D
Lecture Outline • Why do we eat the way we do? • Overview of the Study of Nutrition • Nutrients and their roles in the body • Scientific process in Nutrition
Why do we eat the way we do? • Sensory • Flavour (taste and smell), texture, appearance • Cognitive • Learned food habits (early experiences with food) • Social factors - time crunch versus relaxing experience • emotional needs • Nutrition and health beliefs • advertising • Environmental • Economic, lifestyle, cultural factors, religious beliefs • Health • Physical restrictions due to disease • Declining taste sensitivity • Age and gender
What drives us to eat? • A complexity of factors influence eating • Hunger - physiological drive to find and eat food • Appetite - primarily psychological influences encouraging us to find and eat food - often in absence of hunger • Satiety - state in which there is no longer a desire to eat; a feeling of satisfaction • Hypothalamus - portion of brain that regulates satiety - influenced by • blood glucose, bulk of meal, composition of meal, hormones
What is Nutrition ? • Nutrition defined as: • Science of foods • and their components (nutrients and other substances), • including the relationships to health and disease (actions, interactions and balances); • processes within the body (ingestion, digestion, absorption, transport, functions and disposal of end products); and the social, economic, cultural and psychological implications of eating.
Nutrients and Nourishment • Nutrients - any substance in food that the body can use to obtain energy, build tissues, or regulate functions • Essential nutrients - substances that must be obtained in the diet because the body either cannot make them or cannot make adequate amounts of them
Six Classes of Nutrients • Organic • Carbohydrates • Proteins • Lipids • Vitamins • Inorganic • Minerals • Water • Diet must supply about 45 Essential Nutrients
General Functions of Nutrients • Fig 1.9 • Regulate Body Process • proteins, lipids, vitamins, minerals, water • Contribute to cell and body structure • Growth and development of bone, muscle and other cells • proteins, lipids, vitamins, minerals, water • Provide Energy • carbohydrates, proteins, lipids • calorie - heat energy needed to raise one gram of water by one degree Celsius. (1 kcal = 1000 cal). • Food labels use cal in place of kcal
Carbohydrates • Major source of fuel (4 kcal/gram) • Carbon, Hydrogen and Oxygen • Simple sugars - glucose • Sucrose (glucose-fructose) • Complex sugars • storage forms - links between simple sugars • Eg, glucose-glucose-glucose-glucose-glucose-glucose-glucose • Starch (potatoes, rice) • Dietary Fiber (un-digestible - bran, apple skin)
Lipids • Concentrated fuel (9 kcal / g) • Fats (solid) and Oils (liquid) at room temperature • Do not dissolve in water • Triglycerides are major form of lipid • Fatty acids are the basic structural unit • Saturated - generally solid, animal derived • Unsaturated - generally liquid, plant derived • Some Fatty acids are essential nutrients - vital for cell synthesis and repair • one table spoon of vegetable oil supplies our daily requirements • omega 3 and omega 6 - healthy fish oils
Proteins • Major component of Body Structure • muscle, bone, enzymes, hormones • Energy (4 kcal / g) • Amino Acid is structural unit • 20 types, 9 are essential • Typical consumption is 1.5 to 2 times dietary need • excess is used for energy or stored as carbohydrate or FAT
Vitamins and Minerals • Needed in small amounts • not a direct source of energy • high potential for toxicity • balanced diet can easily supply all vitamins and minerals • should not rely on supplements
Vitamins • Essential - carbon containing substances (Organic) • Enable many chemical reactions to occur in body • 13 kinds • 4 fat soluble A, D, E and K • potential for toxic build up • 9 water soluble • easily excreted, but can be destroyed by cooking
Minerals • Inorganic ions • Not a source of energy • Role in facilitating metabolism • Iron in oxygen transport • Sodium in nerve conduction • Calcium in muscle contraction • Make up structure of body and components of blood stream • eg. Calcium in bones • Two groups - Major minerals and Trace minerals - categorization based on dietary needs
Water • Nourishes the body in many vital ways • dissolves substances (solvent) • lubricates joints • provides a means of transport for nutrients and waste • Medium for temperature regulation and chemical processes • body is ~ 60% water, need almost 2 L per day • not a source of energy
Are you what you eat? • The amount of nutrients your body needs varies widely from one nutrient to another. • .5 Kg of energy food • 2.5 Kg of water • mg of vitamins and minerals • Your structure is determined by genetic blueprint, you are not what you eat, but your food is the raw materials.
Energy for Body Function • Energy - capacity to do work • Chemical energy from food converted to mechanical, electrical and heat energy • Carbohydrates, Fats, and Protein • Alcohol is also an energy source • Not an essential nutrient • Typically a contributor to excess energy intake in the diet • energy is in Carbon-Hydrogen bonds • Harnessed by Plants from Suns energy • Used to: - Build compounds • Perform muscular movements • promote nerve transmission • maintain ion balance in cells
Energy in foods • Measured in kilocalories (kcal)
Energy Intake • calorie - energy it takes to raise temperature of 1 gram of water 1 degree Celsius • Nutrition - use kilocalories (1000 calories) - same as common Calorie • Typical diet (% of total calories) • Protein 16%, Carbohydrates 50% Fats 33% • Recommend • P(15%), C(50-60%), F(25-35%) • Use Food labels - fig 2.11- Canadian p D12 • Common Dietary Problems • reduced activity, increased caloric intake • obesity, health risks • low vegetable and fruit intake • Missing major sources of vitamins and minerals
One bagel plus 1.5 ounces of cream cheese contains 39 grams of carbohydrate 10 grams of protein 16 grams of fat 39 g carbohydrate x 4 kcal/g = 156 kcal 10 g protein x 4 kcal/g = 40 kcal 16 g fat x 9 kcal/g = 144 kcal Total = 340 kcal Calculating Energy in Foods
Applying the Scientific Process to Nutrition • Scientific method • Types of studies • Epidemiological • Animal • Cell culture • Human • Case control • Clinical trial
Finding Scientific Information Versus Misinformation • As scientific information is made accessible to more and more people, less detail is provided and more opinion and sensationalism are introduced. • Sources include professional journals, scientific magazines, generalist magazines and newspapers, nightly news bites, unattributed Internet sites.
Evaluating Information on the Internet: Red Flags of Junk Science • Recommendations that offer a quick fix • Dire warnings of danger from a single product or regimen • Claims that sound too good to be true • Simplistic conclusions drawn from a single study • Dramatic statements that are refuted by reputable scientific organizations • Evidence vs hype
Kin 110 Chapter 2 Nutritional Guidelines and Assessment
Overview of Lecture • Chapter 2 • Tools for diet design • Food Guide and its uses • Dietary Guidelines • Recommended Nutrient Intakes • Food Labeling • Nutrient Density and the Exchange System • Nutritional Assessment
Dietary Planning Principles Six dietary planning principles form the foundation of all health diets. Adequacy • provides sufficient energy and enough of all of the nutrients to meet the needs of healthy people Balance • provides an appropriate distribution of nutrients
Dietary Planning Principles - kiloCalorie Control • management of food energy intake (avoids over consumption of energy) • Nutrient Density - nutrients obtained in relation to overall kilocalories - aim to maximize • Energy Density - energy obtained per gram of food - aim to minimize Example of nutrient density 1 cup skim milk 301 mg Calcium 85 kcal 1 cup whole milk 290 mg Calcium 150 kcal
Dietary Planning Principles cont. Moderation • avoiding extremes of energy or nutrient consumption • Keeping serving sizes reasonable Variety • consuming a wide selection of different foods • why is variety important?
Canada’s Guidelines for Healthy Eating • Enjoy a VARIETY of foods • Emphasize cereals, breads, other grain products, vegetables, and fruits • Choose lower fat dairy products, leaner meats, and foods prepared with little or no fat • Achieve and maintain a healthy body weight by enjoying regular exercise and healthy eating • Limit salt, alcohol, and caffeine
Eating Well with Canada’s Food Guide • group foods according to the primary nutrients they contain & similarity in origin • used to assess the diet for adequacy & assist in diet planning • many foods can contribute to more than one food group • a balanced diet means choosing foods from each group • a varied diet means choosing different foods form within each food group
How much from each food group should I consume? Female (Age 19-50) Male (Age 19-50) Create your own food guide
Estimating Serving Sizes • 3 oz meat ≈ a deck of cards • 1.5 oz of cheese ≈ 3 dominoes • 1 cup ≈ a baseball • 1 tsp ≈ tip of thumb • 1 medium fruit ≈ 1 tennis ball • 2 tablespoons ≈ golf ball or shot glass • 2 once bagel ~ 1 hockey puck • 1/2 cup cooked rice or pasta~ tennis ball
Recommendations for Nutrient Intake • Dietary Reference Intakes (DRIs) • Recommendations for nutrient intake • Developed by the Food and Nutrition Board • Apply to healthy people in the United States and Canada • Four basic elements
Dietary Reference Intakes (DRIs) • Estimated Average Requirement (EAR) • Amount that meets the nutrient requirements of 50% of people in a life stage/gender group • Based on functional indicator of optimal health • Recommended Dietary Allowance (RDA) • Amount that meets the needs of most people (97-98%) in a life stage/gender group
Dietary Reference Intakes (DRIs) • Adequate Intake (AI) • Amount thought to be adequate for most people • AI used when EAR and RDA can’t be determined • Tolerable Upper Intake Level (UL) • Intake above the UL can be harmful
Dietary Reference Intakes (DRIs) • Using the DRIs • Population groups • Assess adequacy of intake • Plan diets • Set policy and guidelines • Individuals • Use RDA and AI as target levels for intake • Avoid intake above the UL
Food Labels • Mandatory information on food labels • Statement of identity • Net contents of the package • Name and address of manufacturer, packer, distributor • List of ingredients • Listed in descending order by weight • Nutrition information
Canadian Nutrition Food Labeling(p D12) Nutrition Facts Box Daily values based on recommendations for healthy eating. Provide context for the amount of nutrient. Nutrient information based on a specified amount of food for easy comparisons allows calculation of the percent energy derived from each of the energy yielding nutrients allow for quick evaluation of contribution to daily needs, comparison between products and estimation of nutrient density