Nutrition: Basic Terms. Nutrition: Basic Terms. Nutrition: Basic Terms. Nutrition: Basic Terms. The Nutrients. Nutrition is the science of:

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1 Nutrition: Basic Terms (Otherwise known as Chapter 1) Nutrition is the science of: Food Diet Nutrients Nutrition: Basic Terms Food Derived from plant or animal sources Provides nutrients and other substances Usually consumed by eating & drinking Also: tube feedings, vein feedings Nutrition: Basic Terms The food that one consumes is their DIET How do people choose what they eat? Diet quality (and the substances it contains) affects the risk of chronic disease Nutrition: Basic Terms Nutrients Substances from food used by body for: Energy Structural Materials Regulation functions So the body can grow, maintain, and repair its tissues Also: Some roles not completely defined yet! The Nutrients Essential nutrients Must be obtained from external source because body can t manufacture enough to meet needs Non-essential nutrients Needed by the body BUT can make enough e.g. cholesterol Non-nutrients Additives, preservatives, alcohol, fiber, phytochemicals (biologically-active compounds,but not in nutrient roles) 1

2 The Nutrients Macronutrients Needed in larger amounts (grams--g) Micronutrients Needed in smaller amounts (milligrams--mg, micrograms--mcg or µg) Macronutrients All of the Macronutrients are also Organic nutrients, i.e., they contain Carbon Carbohydrates (CHO) Energy!!!!! Lipids (aka Fats) Energy Structure (adipose, cell membranes) Regulation (some hormones) Proteins Structure (muscle, cell membranes) Regulation (enzymes, some hormones) Energy (not its best role!) Macronutrients Most foods are a blend of all of the macronutrients except for Pure sugar (pure CHO) Oils (pure lipid) Energy: the capacity to do work calories = chemists Kilocalories= Kcalories=Kcal What we refer to with food (aka calorie in popular press) Energy Density What happens to excess energy? Changes roles: Structure Storage form of energy is fat! How many kcal there are relative to amount (grams) of food 2

3 Micronutrients Vitamins: also organic compounds And, thus, are fragile, so can be destroyed with poor cooking/handling techniques They DO NOT provide energy by themselves!!! Main role: Regulation Coenzymes: Enzymes little helpers Micronutrients Minerals: inorganic compounds They DO NOT provide energy Main role #1: Regulation: Cofactors: co-enzymes little helpers Main role #2: Structure: E.g.: Bones contain calcium, phosphorus Water But that s not all The last nutrient is also the most important! Needed in liters/day Inorganic Role: Regulation Involved in practically every metabolic reaction! Our Favorite Solvent The Nutrients (You are what you eat!) 3

4 Body Composition Are you the milk or the Oreos? Both contain the same chemicals that people do BUT not in the same amounts AND they may contain things that we don t! One of the great things about food is: YOU get to decide! McMullen s Food Choice Modalities Habit Stress/Self-medication Emotions Health Improvement Taste Associations Tradition Availability Auto-Pilot Friends Convenience Social Conditioning Diet Practicality Values Heritage Conscious Price Health Decisions Health Enhancement Unfortunately, health isn t always people s first priority Diet and Health How do we address that? 4

5 Diet and Health Risk Factors for Chronic Diseases Things that make risk factors riskier: Some risk factors are riskier than others The number of risk factors: is there a cluster? How long the risk factor persists Some risk factors are easier to control than others Good Nutrition is Essential To Good Health and Wellness How do we know how much we need of each nutrient? Dietary Reference Intakes (DRIs) The entire set of recommendations for individual nutrients Estimated Average Requirements Recommended Dietary Allowances Adequate Intakes Tolerable Upper Limits DRI 5

6 DRIs DRI Estimated Average Requirements (EAR): the average daily amount that meets the needs of HALF of the healthy people in an age/gender group Recommended Dietary Allowance (RDA): the average daily amount that meets the needs of practically all of the healthy people in an age/gender group Other DRIs Adequate Intake (AI): the recommendation given if there is not enough scientific evidence to establish a RDA Tolerable Upper Intake Level (UL): the maximum daily amount that appears safe for most healthy people Energy Recommendations Estimated Energy Requirement: Set a little differently! Energy Recommendations Where should energy come from? Acceptable Macronutrient Distribution Ranges Carbohydrate: 45% - 65% Fat: 20% - 35% Protein: 10% - 35% 6

7 Using Nutrient Recommendations Established for HEALTHY people Recommendations Requirements Optimal Recommendations should be met by consuming a diet of various FOODS Recommendations apply to AVERAGE daily intakes Who comes up with this stuff anyway? Remember: Nutrition is a Science Research Vs. Rumors Scientific validity The Scientific Method Epidemiological studies Laboratory-based studies Human intervention or clinical trials 7

8 The Scientific Method Epidemiological studies Laboratory-based studies Human intervention or clinical trials Don t jump to conclusions!!! Correlation Causation Can the findings be replicated? It takes a lot of experiments to establish a theory! How good is this research? Experimental group vs. control group Adequate placebo? Not well randomized Single vs double-blind experiments Sample size: often too small Games with statistics, interpretation Not peer reviewed; researcher bias How do we know what to believe? 8

9 Nutrition Information and Misinformation Not everything on the Internet is true!! Determination of the reliability of a website Highlight 1 Not everything on the news is accurately reported!! Nutrition Information and Misinformation Finding credible information p.33 Government health agencies Professional health organizations Peer-reviewed journals Nutrition Information and Misinformation Identifying misinformation What are their qualifications? Are they making a profit off of you? 9