Nutrition Food for Health 02 10 2015 1 Nutrition A science that studies all the interactions that occurs between living organisms and food 2 Nutrients Substances in food that provides energy structure and helps regulate body processes 3 Essential Nutrients Nutrients that must be provided in the diet because the body either cannot make it or cannot make it sufficiently to satisfy its needs a Carbohydrates b Fats and Oils c Proteins d Vitamins e Minerals f Water 4 Macronutrients Nutrients needed by the body in large amounts It is measured in kilograms kg or grams g 5 Micronutrients Nutrients needed by the body in small amounts It is measured in milligrams 1mg 1 1000 g or micrograms 6 Organic Molecules A molecule that contains carbon bonded to hydrogen which includes carbohydrates lipids proteins and vitamins 7 Inorganic Molecules A molecule that does not contain carbon hydrogen bonds which includes minerals and water 8 Energy Yielding Nutrients Nutrients that an be metabolized to provide energy for the body measured in kilocalories aka Kcalories kcal or in kilojoules kJs In popular press calorie small c is used to express the kcalorie contents of food or one s diet Carbohydrates 4 kcal per gram Lipids 9 kcal per gram Proteins 4 kcal per gram 9 What Nutrients Do Provide energy maintain bodily functions physical activity Form and maintain structures Regulate body processes life temperature physical activity sugar level etc 10 What Determines Food Choices Availability Cultural and Family Background Social Acceptability Personal Preference Psychological and Emotional factors Health Concerns Nutrition Guidelines Applying the Science of Nutrition 02 10 2015 Early 1940s WWII establishment of nutrient intake recommendations 1 Recommended Dietary Allowances RDAs Intakes that are sufficient to meet the nutrient needs of almost all healthy people in a specific life stage and gender group ex protein iron calcium vitamin A and D thiamin riboflavin niacin Vitamin C the original RDAs made recommendations for amounts of energy and for nine essential nutrients that were most likely to be deficient in diets Recommended intakes were based on amounts that prevent deficiencies The original RDAs resulted in less to no nutrient deficiencies but an increase of nutrient related chronic diseases such as heart disease diabetes osteoporosis obesity etc That leads to the establishment of Dietary Guidelines for Americans in 1980 which is revised every five years 2 Dietary Reference Intakes DRIs A set of reference values for the intake of energy nutrients and food components that can be used for planning and assessing the diets of healthy people in the United States and Canada RDAs expanded into DRIs DRIs concern about excess as well as deficiencies 3 Estimated Average Requirements EARs stage group 4 Acceptable Macronutrient Distribution Ranges AMDRs Ranges of intake for energy yielding nutrients expressed as a percentage of total energy intake that are associated with reduced risk of chronic disease while providing adequate intakes of essential nutrients Basically the proportions of carbohydrate lipid and protein intakes A healthy diet for an adult 45 65 of calories from Carbohydrates 20 35 of calories from Fats and Oils Intakes that meet the estimated nutrient needs of 50 of individuals in a gender and life Suggest amounts and types of food from five food groups to meet the recommendations 10 35 of calories from Proteins 5 MyPlate of the 2010 Dietary Guidelines Emphasizes the importance of proportionality variety moderation and nutrition density in a healthy diet MyPlate icon Shows how much of each food group for your plate a Avoid oversized proportions b Make half your plate fruits and vegetables c At least half your grains whole grains d Low sodium e Water instead of soft drinks 6 Food and Supplement Labels poultry products regulated by USDA Daily Values helps consumers determine how a food fits into their overall diet Label claims Serving Sizes Food and Drug Administration FDA regulates the labeling of all foods except meat and a Nutrient content claims free low lean extra lean good source b Health claims low fat milk may indicate that a diet high in calcium will reduce c Structure function claims Fiber maintains bowel regularity calcium builds the risk of osteoporosis strong bones Digestion Absorption and Metabolism 02 10 2015 1 Digestion The process of breaking food into components small enough to be absorbed into the body Digestion includes breaking food down mechanically chemically Digestive juices secreted from Salivary glands Stomach Small Intestine Liver via gallbladder Pancreas Digestive secretions bring abundance of water and a variety of digestive enzymes 2 Enzymes A protein that induces a chemical change in another substance Enzymes speed up the rate of chemical reactions Digestion is dependent on many different enzymes 3 Organs of the Digestive System a hollow tube consisting of the mouth pharynx esophagus a Gastrointestinal GI tract stomach small intestine large intestine and anus in which digestion and absorption of nutrients occur b Accessory Organs Salivary glands liver pancreas and the gallbladder 4 Digestion in the Mouth Digestion begins in the mouth Chewing is the mechanical digestion that breaks food into smaller pieces Chemical digestion o Presence of food in the mouth stimulates the flow of saliva from salivary glands o Saliva Moistens the food so that it can easily be tasted and swallowed Cleanses the mouth and protects teeth from decay Lubricates the upper GI tract Begins the enzymatic digestion of carbohydrates because it contains the enzyme salivary amylase o Salivary Amylase o Lingual Lipase An enzyme secreted by the salivary glands that breaks down starch An enzyme secreted by the salivary glands that begins the chemical digestion of lipids in the mouth The tongue initiates swallowing by moving the mass of chewed food mixed with saliva back toward the pharynx Pharynx A funnel shaped opening that connects the nasal passages and mouth to the respiratory passages and esophagus It is a common passageway for food and air and is responsible for swallowing Shared by both the digestive tract and the respiratory tract Epiglottis A piece of elastic connective tissue at the back of the throat that covers the opening of the passageway to the lungs during swallowing Food travels from the mouth to the stomach through the esophagus Peristalsis the coordinated muscular contractions that move