Nutrition Lecture Notes QUIZ 1 1 9 14 INTRODUCTION Nutrition The science of food the nutrients and the substances therein their action interaction and balance in relation to health and disease and the process by which the organism ingests absorbs transports utilizes and excretes food substances Nutrients chem substances in food that provide energy structural material and or regulating agents to support growth maintenance and repair of the body s tissues Other substances Add flavor texture color additives pigments Have physiological effects caffeine Have important health benefits fiber phytochemicals Essential nutrient a nutrient that MUST be obtained from food bc the body cannot make it or cannot make an adequate amnt of it to meet physiological needs 6 nutrients Carbohydrates macronutrient organic provides energy Composed of C H O Major source of fuel for the body Starches and sugars Found in largest proportion in grains F V legumes dry beans and peas dairy products Body converts dietary CHO to blood sugar or glucose Lipids macronutrient organic provides energy contributes to cell body structure regulates body processes Composed of C H O Key functions Major source of fuel for body Cell membranes Important for fat soluble vitamin absorption and transport Starting material for many hormones Protein macronutrient organic provides energy contributes to cell body structure regulates body processes Contain N in addition to C H O Composed of smaller building blocks called amino acids 9 Essential amino acids Animal protein soy Complete protein Builds and maintains body structure regulates body processes fuel source Water macronutrient inorganic contributes to cell body structure regulates body processes Most essential nutrient o Body is 60 water Many important roles Can survive longer without any other nutrient than without water o Participates in metabolic reactions o Nutrient transport and waste elimination o Temperature regulation o Maintain pH balance Vitamins micronutrient organic regulate body processes Fat Soluble Water Soluble Found in a wide variety of foods Main Role Regulate body processes o Vital role in extracting energy from macronutrients o Blood clotting Calcium balance Minerals micronutrient inorganic contribute to cell body structure regulate body processes Structurally simple inorganic substances Major and Trace minerals o 16 are Essential Found in a variety of foods Structural roles as well as regulatory Deficiencies uncommon except for calcium and iron Energy Energy in food potential energy contained in a food Kilocalorie amount of E it takes to 1 kg of H20 by 1 degree C Amount of energy measured by amount of carbs protein fat and alcohol it contains CHO 4 kcal g Protein 4 kcal g Fat 9 kcal g OH 7 kcal g not a nutrient though EX Per serving CHO 15g x 4 kcal g 60 kcal Protein 3g x 4 kcal g 12 kcal Fat 1g x 9 kcal g 9 kcal TOTAL 81 kcal rounded down to 80 SUMMARY There are many factors that influence people s food choices Essential nutrients are nutrients that are not synthesized by the body in adequate amounts and must be consumed in the diet Macronutrients Carbs Proteins Lipids Water Micronutrients Minerals Vitamins Nutrient functions Provide energy structure and regulate body processes Kilocalorie measure of potential energy in foods the amount of heat required to raise one kg of water one degree Celcius Carbohydrate and Protein provide 4 kcal g Fat provides 9 kcal g see calculation worksheet NUTRITION AND THE SCIENTIFIC PROCESS NUTRITIONAL ASSESSMENT Nutrition scientific process to test hypotheses that arise from observations of natural phnomena Research Design Experimental Studies Animal Studies H0 generating Cell Culture Studies H0 generating Clinical trials Intervention studies H0 testing Epidemiology Studies Epidemiologic research Concerned with the distributions and determinants of disease frequency in human populations Descriptive Epidemiology Concerned with the distribution of disease Hypotheses generating Ecological Studies Correlational Studies o Uses data from populations to compare disease frequency between different groups during some time period or in same population at different points in time Cross sectional Studies o Examine exposure and disease in individuals within a population at the same point in time e g NHANES Analytic Epidemiology Focuses on the determinants of disease by testing hypotheses compare those who develop a disease with those who do not Observational effective o Case control start with the disease includes recall bias least o Cohort studies prospective retrospective start with exposure includes loss to follow up bias Intervention clinical trials Nutritional assessment A anthropometric measures o Similar to a prospective cohort study yet exposure is assigned by the investigator o Ethics Balance between possibility and uncertainty of Benefit o Also Issue of cost and feasibility NHANES Designed to assess health and nutritional status of adults and children in US Began in 1960 as NHES Became continuous survey in 1999 Prevalence of disease risk factors Became NHANES in 1971 when major nutrition movement was added Assess association between nutritional factors and disease promotion prevention Placebo effect response by subjects to a treatment regardless of the physiologic efficacy of what they receive due to expectations Nutritional epidemiology Strength direct relevance to human health pub Health recommendations Limitations complex nature of diet evolves over time complex mixture of foods compounds components are intercorrelated difficult to have a single blind trial measurement of human physical dimensions BMI Age wt or height wt 5 BMI malnutirion 85 95 overwt 95 obese B biochemical test C clinical observations D dietary intake measures a nutrient or metabolite in one body fluids evaluating the characteristics of health that can be seen during a physical exam Direct observation clinical research lab Food chosen for you measure remaining food Diet history Discuss frequent diet 24 recall Diet record List detail description estimate review Shows day to day variability but a good estimate average nutrient intake of a population Record household measure of all food and beverages for 3 7 days including 1 weekend day Less prone to memory lapses but tend to ease diet Food frequency questionnaire provide descriptive qualitiative information about usual food consumption patterns over specific time Enables ranking of individuals on basis of