The science of foods and the nutrients and other substances they contain and of their actions within the body

Transcription

1 HLTH 1050 Week 1

2 The science of foods and the nutrients and other substances they contain and of their actions within the body Including ingestion, digestion, absorption, transport, metabolism and excretion. A broader definition includes the social, economic, cultural, and psychological implications of food and eating. Source: Understanding Normal and Clinical Nutrition. S.R. Rolfes, K. Pinna, and E. Whitney. Thomson Wadworth Publishers, 2009, Eighth Edition

3 Chemical substances obtained from food and used in the body to Provide energy, structural materials, and regulating agents to support growth, maintenance, and repair of the body s tissues. Nutrients may also reduce the risks of some diseases

4 Nutrients a person must obtain from food because the body cannot make them for itself in sufficient quantity to meet physiologic needs. Source: Understanding Normal and Clinical Nutrition. S.R. Rolfes, K. Pinna, and E. Whitney. Thomson Wadworth Publishers, 2009, Eighth Edition

5 Nutrients for which specific biological functions have been identified and which the body cannot synthesize in sufficient quantities to meet our biological needs. Essential nutrients must be provided through the diet. Thompson JL, Manore MM, Vaughan LA. The Science of Nutrition. Pearson Education, Inc

6 Energy-Yielding (Macronutrients) (organic) Carbohydrates Lipids (Fats) Protein Non-Energy- Yielding (Micronutrient) Vitamins (organic) Minerals (inorganic) Fluid Water (inorganic)

7 Macronutrients: nutrients needed by the body in large amounts (grams) Carbohydrates, protein, lipids Micronutrients: nutrients needed by the body in small amounts (milligrams or micrograms) Vitamins and minerals Organic nutrients: contain carbon-to-carbon or carbon-to-hydrogen bonds Carbohydrates, protein, lipids, vitamins Inorganic nutrients: do not contain carbon minerals 2010 U.S. Dietary Guidelines

8 Calories are the units by which energy is measured, however, A calorie is a very small unit of energy. Most foods contain tens of thousands of them. To ease calculations, energy is expressed in metric units known as kilocalories or kcal. When popular books, magazines or food labels state that a food provides 100 calories, it actually means 100 kcalories.

9 Also known as kcalorie or kcal One kilocalorie is the amount of heat necessary to raise the temperature of 1 kilogram (kg) of water 1 C. The scientific use of the term kcalorie is the same as the popular use of the term calorie.

10 A measure of energy that food provides relative to the amount (weight) of food Kcalories per gram of food Examples Green beans (cooked from frozen) provide 0.26 kcal/gram French fries (typical fast food serving) provide 3.19 kcal/gram

11 2010 U.S. Dietary Guidelines

12 A measure of the nutrients a food provides relative to the energy it provides. The more nutrients and the fewer calories, the higher the nutrient density. Low nutrient dense foods supply calories but relatively small amounts of micronutrients, sometimes none at all.

13 Nutrient-dense or "nutritionally rich" foods include: Brightly colored fruits and 100% fruit juices Vibrant colored vegetables and potatoes Whole, fortified and fiber-rich grain foods Low-fat and fat-free milk, cheese and yogurt Lean meat, poultry, fish, eggs, beans and nuts

14 Estimated Average Requirements Recommended Dietary Allowances Adequate Intakes Tolerable Upper Limits Estimated Energy Requirements Acceptable Macronutrient Distribution Range

15 Establishing Nutrient Recommendations Estimated Average Requirement (EAR) defines the requirement of a nutrient that supports a specific function in the body for half of the healthy population. Used to set the RDA. Recommended Dietary Allowances (RDA) use the EAR as a base and include sufficient daily amounts of nutrients to meet the known nutrient needs of practically all healthy populations. This recommendation considers deficiencies.

16 Establishing Nutrient Recommendations Adequate Intakes (AI) reflect the average daily amount of a nutrient consumed by healthy people that appears to be sufficient. More tentative than an RDA because scientific evidence is lacking. Tolerable Upper Intake Level (UL) is a maximum daily amount of a nutrient that appears safe for most healthy people and beyond which there is an increased risk of adverse health effects.

17 Estimates of energy & nutrient intakes apply to healthy people Recommendations are NOT minimum requirements Recommendations are NOT optimal for all people

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

19 DRI s for vitamins & minerals (RDA & AI) provide a generous margin of safety and are established to meet the needs of almost all healthy people.

20 2010 U.S. Dietary Guidelines

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22 DRIs for energy (EER) do not provide this margin of safety. Because obesity is such a public health concern, the standards are set at the average for the population group.

23 Estimated Energy Requirement (EER) Represents average daily energy intake to maintain energy balance and good health for population groups. Excess energy cannot be excreted, it is stored as fat

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25 EER (kcal/day) Different EER formulas for age, gender PA = physical activity factor Adult EER Formula: Men age 19 and older EER = [662 (9.53 x age)] + PA x [(15.91 x wt) + (539.6 x ht) (± 200 kcal for most men) Women age 19 and older EER = [354 (6.91 x age)] + PA x [(9.36 x wt) + (726 x ht)] (± 160 kcal for most women)

26 Interactive DRI for Healthcare Professionals Enter gender Females enter pregnancy status Enter age You have to check either years or months Enter height, weight, & select an activity level Check Body mass index, Daily Calorie Needs and anything else you are interested in Click Submit to get a personal report

27 DRIs for carbohydrate and protein (RDA) are established to prevent deficiencies of these two macronutrients. DRIs for energy nutrients (AMDRs) are set to provide a balance of energy from macronutrients that will reduce the risk of chronic disease

28 The AMDR for carbohydrate is set to ensure appropriate balance between carbohydrate and fat to reduce risks for coronary heart disease and obesity The RDA for protein for adults represents about 10% of energy intake; the AMDR for protein was set at 10-35% of energy intake to complement the AMDRs for carbohydrate and fat and to ensure a nutritionally adequate diet.

29 Acceptable Macronutrient Distribution Range (AMDR) range of intakes for energy nutrients that provide adequate energy and nutrients and reduce risk of chronic disease. Macronutrient Carbohydrate 45-65% Fat 20-35% Protein 10-35% Recommended % of total kcal

30 First published in 1980 Shared responsibility United States Department of Agriculture (USDA) United States Department of Health and Human Services Since 1990, the government is required, by law, to review and update the Guidelines every 5 years Dietary Guidelines for Americans 2010 were issues January 31, U.S. Dietary Guidelines

31 The Guidelines provide authoritative advice for people two years and older about how good dietary habits can promote health and reduce risk for major chronic diseases. They serve as the basis for Federal food and nutrition education programs U.S. Dietary Guidelines

32 Two overarching concepts 1. Maintain calorie balance over time to achieve and maintain a healthy weight 2. Focus on consuming nutrient-dense foods and beverages U.S. Dietary Guidelines

33 Balancing calories to manage weight Prevent and/or reduce overweight and obesity through improved eating and physical activity behaviors Control total calorie intake to manage body weight. For people who are overweight or obese, this will mean consuming fewer calories from food and beverages Increase physical activity and reduce time spent in sedentary activities Maintain appropriate calorie balance during each stage of life childhood, adolescence, adulthood, pregnancy and breastfeeding, and older age U.S. Dietary Guidelines

34 Food and Food Components to Reduce Reduce daily sodium intake to less than 2,300 milligrams (mg) and further reduce intake to 1,500 mg among persons who are 51 and older and those of any age who are African American or have hypertension, diabetes, or chronic kidney disease. The 1,500 mg recommendation applies to about half of the U.S. population, including children, and the majority of adults U.S. Dietary Guidelines

35 Foods and Food Components to Reduce Consume less than 10 percent of calories from saturated fatty acids by replacing them with monounsaturated and polyunsaturated fatty acids Consume less than 300 mg per day of dietary cholesterol Keep trans fatty acid consumption as low as possible by limiting foods that contain synthetic sources of trans fats, such as partially hydrogenated oils, and limiting other solid fats 2010 U.S. Dietary Guidelines

36 Foods and Food Components to Reduce Reduce the intake of calories from solid fats and added sugars (SoFAS). Limit the consumption of foods that contain refined grains, especially refined grain foods that contain solid fats, added sugars, and sodium If alcohol is consumed, it should be consumed in moderation up to one drink per day for women and two drinks per day for men and only by adults of legal drinking age 2010 U.S. Dietary Guidelines

37 Food and Nutrients to Increase Increase vegetable and fruit intake Eat a variety of vegetables, especially dark green and red and orange vegetables and beans and peas Consume at least half of all grains as whole grains. Increase whole-grain intake by replacing refined grains with whole grains Increase intake of fat-free or low-fat mik and milk products, such as milk, yogurt, cheese, or fortified soy beverages 2010 U.S. Dietary Guidelines

38 Foods and Nutrients to Increase Choose a variety of protein foods, which include seafood, lean meat and poultry, eggs, beans and peas, soy products, and unsalted nuts and seeds Increase the amount and variety of seafood consumed by choosing seafood in place of some meat and poultry Replace protein foods that are higher in solid fats with choices that are lower in solid fats and calories and/or are sources of oils 2010 U.S. Dietary Guidelines

39 Foods and Nutrients to Increase Use oils to replace solid fats where possible Choose foods that provide more potassium, dietary fiber, calcium and vitamin D, which are nutrients of concern in American diets. These foods include vegetables, fruits, whole grains, and milk and milk products U.S. Dietary Guidelines

40 Building Healthy Eating Patterns Select an eating pattern that meets nutrients needs over time at an appropriate calorie level Account for all foods and beverages consumed and assess how they fit within a total healthy eating pattern Follow food safety recommendations when preparing and eating foods to reduce the risk of foodborne illnesses 2010 U.S. Dietary Guidelines

41 Combination of foods & beverages that constitute an individual s complete dietary intake over time, e.g., a description of a customary way of eating A combination of foods recommended for eating, e.g. USDA Food Patterns Dietary Approaches to Stop Hypertension (DASH) Mediterranean diet Vegetarian and vegan patterns Dietary Guidelines for Americans U.S. Dietary Guidelines

42 Adequacy Variety Balance Moderation 2010 U.S. Dietary Guidelines

43 Adequacy Obtaining enough energy, vitamins, minerals, fiber, and fluid to maintain a person s health Balance Consuming a combination of foods that provide the proper proportions of nutrients Moderation Eating the right amount of food to maintain a healthy weight and optimize the body s metabolic processes Variety Eating many different foods from different foods groups on a regular basis 2010 U.S. Dietary Guidelines

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45 Tested in clinical trials - shown to lower blood pressure, improve blood lipids, and reduce cardiovascular risk compared to typical US diets Emphasizes vegetables, fruits, & low-fat milk & milk products Includes whole grains, poultry, seafood & nuts Lower in sodium, red & processed meats, sweets & sugar-containing beverages than typical US diets Dietary Guidelines for Americans 2010

46 Traditional eating patterns throughout the Mediterranean region, especially in Crete during the 1960 s, are associated with a low risk of cardiovascular diseases. No one eating pattern and no single set of criteria for what constitutes a traditional Mediterranean eating pattern Generally, it emphasizes vegetables, fruits & nuts, olive oil & whole grains. It includes only small amounts of meats and full fat milk & milk products. It often includes wine with meals and has a high mono-unsaturated fat to saturated fat ratio Dietary Guidelines for Americans 2010

47 Vary widely Vegan diets contain no animal products Lacto-ovo-vegetarian diets no meat, fish or poultry but do contain milk, milk products, and eggs Some vegetarian diets contain mostly plant foods with small amounts of meat, fish and/or poultry Associated with improved health outcomes Lower levels of obesity Reduced risk of cardiovascular diseases Lower total mortality Dietary Guidelines for Americans 2010

48 Make Your Calories Count - Use the Nutrition Facts Label for Healthy Weight Management: Preface

49 The Ingredient List All ingredients listed Descending order of predominance by weight Example A can of Beef Stew: Ingredients: Ingredients: Beef Gravy (Water, Beef, Tomatoes [Water, Tomato Paste], Corn Flour, Salt, Modified Cornstarch, Caramel Color, Sugar, Flavoring), Potatoes, Beef, Carrots. The ingredient present in the largest amount by weight is beef gravy. The ingredient present in almost the least amount by weight is beef. (Only carrots are present in a smaller amount.

50 Serving Sizes Facilitate comparisons among foods Do not necessarily match the USDA Food Guide Established by FDA for some foods, e.g, ice cream (1/2 cup); beverages (8 fluid ounces) Need to compare to quantity of food actually eaten

51 Nutrition Facts panel Listed by quantity and percentage of standards per serving, called Daily Values Daily Values (DV) reference values developed by the FDA specifically for use on food labels

52 Calories* listed as total calories and calories from fat Fat listed by total fat, saturated fat, and trans fat Cholesterol Sodium Carbohydrate listed by total carbohydrate, starch, sugars, and fiber Protein Vitamin A, vitamin C, iron, and calcium & other micronutrients are listed in % DV only. *Remember calories are actually kcalories!

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54 The Daily Values (DV) Estimate of an individual food s contribution to a total diet Based on 2000-kcalorie diet Help consumers compare foods Special Note: The DV on most food labels is for individuals 4 years of age and older. There is also a DV for infants and children younger than 4 years which is used for foods specifically intended for infants and very young children.

55 Three types of claims allowed on a food label Nutrient claims statements that characterize the quantity of a nutrient in a food; FDA regulations place some restrictions on how these claims can be made to prevent confusion for or intentional misleading of consumers Health claims statements that characterize the relationship between a nutrient or other substance in a food and a disease or health-related condition; FDA requires label disclaimers when evidence for the claim is limited or not conclusive. Manufacturers won the right to make these claims, with the disclaimers, in court decisions upholding their right to free speech.

56 Nutrient Claims Must meet FDA definitions and include conditions of use No implied claims E.g., claims that a product contains no oil which implies it is fat free, can only be made for a product that is truly fat free. Energy terms include kcalorie-free ( < 5 kcal/serving) low kcalorie (40 kcal or less/serving) reduced kcalorie (25% fewer kcal/serving than the comparison food)

57 Nutrient Claims General terms include free (synonyms include: without, no, zero ) good source of (10-19% of DV for a given nutrient/serving healthy (low in fat, saturate fat, cholesterol & sodium, and contains at least 10% DV/serving for Vitamin A, Vitamin C, iron, calcium, protein, or fiber, high (20% or more of DV for a given nutrient/serving; synonyms: rich in, excellent source of )

58 Nutrient Claims less (at least 25% less of a given nutrient or kcalories than the comparison food; synonyms include fewer and reduced ) light or lite (1/3 fewer kcalories OR 50% or less of the fat or sodium of the comparison product. Any other use must define what it refers to, e.g., light in color, lite in texture. low (synonyms few, low source of ) more (at least 10% more of the DV for a given nutrient than the comparison product) organic (95% of food s ingredients grown & processed according to USDA regulations for organic labeling).

59 Health Claims A List Heath Claims Significant scientific agreement- these claims do not require disclaimers B List Health Claims There is evidence supporting the claim but the evidence is not conclusive C List Health Claims Evidence is limited and not conclusive D List Health Claims there is little scientific evidence supporting the claim

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61 Structure-Function Claims Claims made without FDA approval Cannot make statements about diseases May be confusing or deceptively similar to health claims

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63 Food Allergen Labeling and Consumer Protection Act (FALCPA) Went into effect January 2006 Requires food manufactures to Declare the top 8 food allergens Declare allergens in colors, flavors & spices Describe allergens in simple terms (milk vs casein) List specific food products (i.e., almonds, cod or shrimp vs nuts or fish)

64 Eight top allergens required to be declared on food labels Milk Eggs Peanuts Tree nuts Fish Shellfish Wheat Soy

65 FALCPA Requirement You may see the following on a food label Ammonium caseinate (milk), semolina (wheat), stone ground corn, maltodextrin OR Ammonium caseinate, semolina, stone ground corn, maltodextrin. Contains milk and wheat.

66 Voluntary Information You may see the following on a food label May contain traces of Manufactured on shared equipment with. Manufactured on a line that produces products Manufactured in a facility that uses.

67 Statements such as may contain are voluntary. There are no laws, regulations or guidelines for the use of these statements. Some manufacturers provide this information to alert you to possible allergens in a product; do not ignore them. Information adapted from: Food Allergy News, April-May, 2007, pg 4 Published by the Food Allergy & Anaphylaxis Network (FAAN) Web site:

68 Enrichment: adding nutrients to a food that were lost during processing so that the food will meet a specified standard. Fortification: adding nutrients to a food that were not originally present or were present in insignificant amounts. Can be used to prevent a widespread nutrient deficiency or to balance the total nutrient profile of a food.

69 In the early 1900 s, refining & milling of grains & removing the bran & germ caused a loss of many nutrients. Nutrient deficiency diseases such as beriberi and pellegra (Chapter 10) were prevalent in many areas. In the1940 s the US government mandated enrichment of bread & cereal products made from milled grains that crossed state lines thiamine, riboflavin & niacin were added; iron was also added.

70 In 1998, the FDA required all enriched bread, flour, corn meal, pasta, rice and other grain products must be fortified with folic acid as well. This was done to prevent neural tube defects (a birth defect). Legislation passed in 1996 Fortification mandated in 1998

71 Production of highly refined grain products also removes fiber, Vitamin B6, magnesium and zinc. Enrichment does not replace these nutrients. For this reason, whole grains are still a vital part of a healthy diet.