63 391 Basic Human Nutrition Food Choices Human

63 -391: Basic Human Nutrition Food Choices & Human Health Lecture 1 Elisabeth Strachan

Nutrition in Your Life n Nutrition n n Food n n n The science of foods and the substances they contain Derived from plant or animal sources Provide energy and nutrients Diet n The food one consumes 2

Food Choices n n n Personal preference Habit Ethnic heritage or tradition Social interactions Availability, convenience, economy 3

Food Choices n n Positive and negative associations Emotional comfort Values Body weight and image 4

Nutrients in Foods n There are 6 classes of nutrients: n n n Water, Carbohydrate, Protein, Fat (lipids), Vitamins and Minerals These nutrients are essential to health Non-nutrients 5

Energy-Yielding Nutrients n Kilocalories and kilojoules 6 Copyright 2005 Wadsworth Group, a division of

Energy-Yielding Nutrients n n Energy in the body n Energy for activity n Stored energy Other roles of energy-yielding nutrients 7

Vitamins n n n Organic Not energy-yielding Essential Water-soluble vs. fat-soluble Vulnerable to destruction 8

Minerals n n Inorganic Not energy-yielding Essential Indestructible 9

Water n n n Inorganic Not energy-yielding Essential 10 Copyright 2005 Wadsworth Group, a

Non-nutrients in Foods n Phytochemicals e. g, Beta Carotene, Lycopene, etc. , are non-nutrients in foods. n n Appears to give food its taste, aroma, colour and other characteristics May play a role in disease prevention. 11

Dietary Reference Intakes n n A set of scientifically based nutrient reference values for healthy populations. Used by governments and non-government organizations in: n n n the assessment of nutrient intakes of individuals and groups, planning of diets, development of nutrition education materials, the fortification of foods, and the formulation of supplements and special dietary foods. 12

DRI’s consist of 4 values n n Estimated average requirements Recommended dietary allowances Adequate

Estimated Average Requirement (EAR) n n n The median usual intake value that is estimated to meet the requirement of half the healthy individuals in a lifestage or gender group. Used to determine nutrient adequacy to reduce risk of chronic disease or other disorders. Used to calculate the RDA’s. 14

DRI 15 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Recommended Dietary Allowance (RDA’s) n n The average daily dietary intake level that is sufficient to meet the nutrient requirement of nearly all (> 97 -98%) healthy individuals in a life-stage and gender group. RDA = EAR + 2 SDREQ 16

Adequate Intakes (A. I. ) n n A recommended nutrient intake level based on observed or experimentally determined approximations or estimates of a group (or groups) of healthy people that are assumed to be adequate. Used only when and RDA cannot be determined. 17

DRI 18 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Tolerable Upper Intake Level (UL) n n n The highest level of daily nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects increases. No UL means no data, not no risk. 19

DRI 20 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Energy Recommendations n n Estimated Energy Requirement Acceptable Macronutrient Distribution Ranges n Carbohydrate: 45% - 65% n Fat: 20% - 35% n Protein: 10% - 35% 21 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Energy Recommendations 22 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Using Nutrient Recommendations n n n Estimates of energy & nutrient intakes apply to healthy people Recommendations are NOT minimum requirements Recommendations are NOT optimal for all people 23

Using Nutrient Recommendations n n n Recommendations should be met by consuming a varied diet Recommendations apply to average daily intakes Each DRI category serves a unique purpose 24

Health is affected by: n n n Genetic inheritance Diet choices Lifestyle choices 25

A nutritious diet has 5 characteristics n n n Adequacy: foods provide enough of each nutrient, fibre, & energy Balance: not choosing one food/nutrient over another Calorie control: eating enough to maintain a healthy weight 26

Nutritious diet continued n n Moderation: Foods high in fat, salt, or sugar can be eaten as part of a healthy diet if not eaten to excess. Variety: necessary in order to get all the nutrients one requires. 27 Copyright 2005 Wadsworth Group, a division of Thomson Learning

How do we determine what we should eat? n n n Government agencies provide us with nutrition recommendations and guidelines. Recommendations based on scientific research. These recommendations are translated into food groups & serving sizes of foods, e. g. , Canada’s Food Guide To Healthy Eating 28

A World Tour 29 Copyright 2005 Wadsworth Group, a division of Thomson Learning

A World Tour 30 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Canada’s Guidelines To Healthy Eating n n n Enjoy a variety of food 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 physical activity and healthy eating Limit salt, alcohol and caffeine. 31

Canada’s Food Guide To Healthy Eating 32

“Other” foods n n Includes food and beverages that are not part of any food group but are often used in making meals or consumed as snacks. E. g. , foods that are mostly fats and oils (butter and margarine), sugar ( honey, jam, candies), high-fat and/or high salt snack foods (chips, chocolate bars, cakes, cookies), beverages (tea, coffee, water, soft drinks), and condiments (pickles, ketchup). 33

Limitations of Food Guide How to interpret: n Miscellaneous foods n Mixtures of foods n Ethnic foods that do not appear in the Food Guide 34

Other limitations Understanding: n Nutrient density n Recommended servings n Serving sizes 35 Copyright

36 Copyright 2005 Wadsworth Group, a division of Thomson Learning

Nutrition Recommendations for Canadians n n n The Canadian diet should provide energy consistent with the maintenance of body weight within the recommended range. The Canadian diet should include essential nutrients in amounts recommended. The Canadian diet should include no more than 30% of energy as fat (33 g/1000 calories) and no more than 10% as saturated fat (11 g/1000 calories). 37

Nutrition Recommendations Continued n n n The Canadian diet should provide 55% of energy as carbohydrate (138 g/1000 calories) from a variety of sources. The sodium content of the Canadian diet should be reduced. The Canadian diet should include no more than 5% of total energy as alcohol, or two drinks daily whichever is less. 38

Nutrition Recommendations continued n n n The Canadian diet should contain no more caffeine than the equivalent of four regular cups of coffee per day. Community water supplies containing less than 1 milligram per liter should be fluoridated to that level. These recommendations were established in 1990. 39

Food Labels n Ingredient list n Serving sizes n Nutrition facts n Daily Values

New Nutrition Label Easy to find, easy to read and on more foods 41

Nutrition claims • Regulated statements made when a food meets certain criteria • Optional, so may be found only on some food products • Often on the front of food packages • A quick and easy way to get information about a food 42

Nutrition Claims -examples “A healthy diet low in saturated and trans fats may reduce the risk of heart disease. ” “A healthy diet rich in a variety of vegetables and fruit may help reduce the risk of some type of cancer. ” 43

Serving size • the specific amount of food listed under the “Nutrition Facts” title • all nutrient information is based on this amount of food 44

% Daily Value • can make it easier to compare foods • helps you see if a food has a lot or a little of a nutrient • provides a context to the actual amount of a nutrient 45

% Daily Value continued The actual numbers can be confusing, for example: • 2 mg of iron seems small but it is 15 % of the Daily Value for iron • 110 mg of sodium seems large but it is only 5 % of the Daily Value for sodium % Daily Value makes it easy to see if there is a lot or a little of a nutrient without having to do any math. 46

Key Messages . ü Nutrition Facts: easy to find, easy to read, and on more foods ü Use Nutrition Facts, the list of ingredients and nutrition claims to make informed food choices. ü Nutrition Facts are based on a specific amount of food - compare this to the amount you eat. ü Use % Daily Value to see if a food has a lot or a little of a nutrient. 47

Who speaks on Nutrition? n Main sources of nutrition information: n n n n Product labels (ranked 1 st) Radio/TV (ranked 2 nd) Friends/Relatives/Colleagues (ranked 3 rd) Magazines (ranked 4 th) Physicians (ranked 8 th) Dietitian/Nutritionist (ranked 14 th) Internet (ranked last (6%) 48

Nutrition Information and Misinformation n Dietitians of Canada (DC) Registered dietitian (RD) Dietetic technician,

Nutrition Information and Misinformation n Identifying misinformation 50 Copyright 2005 Wadsworth Group, a division

Fads, Frauds and Quackery n n Food Faddism is defined as the adoption of an unusual pattern of food behaviour. Quackery is defined as the promotion for profit of a medical scheme or remedy that is unproven or known to be false. 51

Who Falls Victim to Quackery? n n n People who are: Unsuspecting. If it appears in the media, it’s true Believe in magic, i. e. , believe there is an easy solution Desperate; i. e. , those with serious health problems. Alienated, i. e. , have a deep distrust of governments, medical profession, food companies, etc. 52

Misleading Claims n n n Our food supply is inadequate Vitamin and mineral deficiencies are common. Most health problems can be cured by nutritional methods. Canadians are being poisoned by food additives and pesticide residues. Personal experience is the best way to tell whether a health related action is effective. 53

Dubious Credentials n n n Many promoters of nutrition quackery claim degrees and titles of Dr. , Ph. D. , consultant or medical nutritionist, etc. , which are false and do not exist. Title of Registered Dietitian is protected in both Canada and the USA. Title, Nutritionist is not. 54

Cost of Nutrition Quackery n n Economic loss from a few dollars to thousands of dollars for seriously ill people, e. g. , Laetrile for cancer. Death or disability from unproven and harmful remedies, e. g. , Ma Huang (ephedra) for weight loss, potassium for treating colic in babies. 55

Credible sources of Nutrition Information n n Professional health associations like the Dietitians of Canada, American Dietetic Association Government organizations like Health Canada Volunteer agencies like Canadian Cancer Society, Heart & Stroke Foundation, Canadian Diabetes Association Reputable consumer groups like National Council Against Health Fraud 56

Internet Site Reliable? n n n Who is responsible for the site? Do the names and credentials of information providers appear? Are links with other reliable information sites provided? Is the site regularly updated? Is the site selling a product or service? Does the site charge a fee to gain access to it? 57

Reliable websites n n n http: //www. navigator. tufts. edu/ http: //www. quackwatch. org/ http: //www. supplementwatch. com/supatoz/ http: //www. lesliebeck. com/index. php http: //www. dietitians. ca/ http: //www. eatright. org/Public/ 58