Human Nutrition Exam 1 modules 1 6 I Module 1 Intro a classes of nutrients and calorie values and functions of each i Carbohydrate Chemically carbohydrates can exist in foods as simple sugars and complex carbohydrates We need sugars and other carbohydrates in our diets primarily to help satisfy the calorie needs of our body cells Carbohydrates provide a major source of calories for the body on average 4 kcal per gram Glucose a simple sugar that the body can derive from most carbohydrates is a major source of calories for most cells When not enough carbohydrate is consumed to supply sufficient glucose the body is forced to make glucose from proteins not a healthy change ii Lipids Lipids mostly fats and oils in the foods we eat also provide energy Lipids yield more calories per gram than do carbohydrates on the average 9 kcal per gram because of differences in their chemical composition They are also the main form for energy storage in the body iii Protein Proteins are the main structural material in the body They are also important components in blood body cells enzymes and immune factors Proteins can also provide calories for the body on average 4 kcal per gram iv Vitamins The main function of vitamins is to enable many chemical reactions to occur in the body Some of these reactions help release the energy trapped in carbohydrates lipids and proteins v Minerals Minerals such as sodium and potassium typically function independently in the body whereas minerals such as calcium and phosphorus function as parts of simple mineral combinations such as bone mineral Minerals are critical players in nervous system functioning water balance structural e g skeletal systems and many other cellular processes but produce no calories as such for the body vi Water Although sometimes overlooked as a nutrient water chemically H2O has numerous vital functions in the body It acts as a solvent and lubricant as a vehicle for transporting nutrients and waste and as a medium for temperature regulation and chemical processes b calculations of numbers and percentage of calories if given grams or percentages of nutrients i You can also use the 4 9 4 estimates to determine what portion of total calorie intake is contributed by the various calorie yielding nutrients Assume that one day you consume 290 grams of carbohydrates 60 grams of fat and 70 grams of protein This consumption yields a total of 1980 kcal 290 4 60 9 70 4 5 1980 ii The percentage of your total calorie intake derived from each nutrient can be determined c Calorie The amount of heat necessary to raise the temperature of one liter of water one degree Celsius Calories in food is a measurement of the heat energy in the food d Hunger vs appetite Hunger is primarily our physical biological drive to eat and is controlled by internal body mechanisms For example as foods are digested and absorbed by the stomach and small intestine these organs send signals to the liver and brain to reduce further food intake Appetite our primarily psychological drive to eat is affected by many external food choice mechanisms such as environmental and psychological factors and social customs Appetite can be triggered simply by seeing a tempting dessert or smelling popcorn popping at the movie theater e Essential nutrition A substance that when left out of a diet leads to signs of poor health The body either cannot produce this nutrient or cannot produce enough of it to meet its needs Then if added back to a diet before permanent damage occurs the affected aspects of health are restored i First at least one specific biological function of the nutrient in the body must be identified ii Second omission of the nutrient from the diet must lead to a decline in certain biological functions such as production of blood cells iii Third replacing the omitted nutrient in the diet before permanent damage occurs will restore those normal biological functions f Phytonutrient A chemical found in plants Some phytochemicals may contribute to a reduced risk of cancer or cardiovascular disease in people who consume them regularly g Satiety The feeling of fullness or satisfaction conveyed by a food or meal II Module 2 Learning tools and assessment a DRI s and what each acronym stands for and define i Dietary Reference Intakes a collection of four guidelines average intake recommended dietary allowance adequate intake and the upper limit The purposes are to 1 Help individuals optimize health 2 Prevent disease 3 Avoid consuming too much of a nutrient b RDAs what does acronym stand for and who it is good for i Recommended Dietary Allowances the average daily dietary intake sufficient to meet the nutrient requirement of approximately 98 of the population The RDA is designed to meet the need of almost all healthy people c ABCDE s of nutrition Anthropometric Biochemical Clinical Dietary and Environmental status d Nutrient density The ratio formed by dividing a food s contribution to the needs for a nutrient by its contribution to energy needs When the contribution to nutrient needs exceeds that to energy needs the food is considered to have a favorable nutrient density for that nutrient e Adequate intake AI and how it is different from RDA i Adequate Intake indicates that there isn t enough data to estimate an EAR thus it is defined as the quantity of intake consumed by groups with no evidence of inadequate nutrient intake Nutrients with an AI do not have an RDA because there is not enough information to get the first step of the RDA the EAR f Daily Values on labels and calculations i The nutrition information on a food label is based on a serving of food and compares it to a person who needs a 2 000 kilocalorie diet using the Daily Values ii Suppose a young adult male needs about 4 000 kilocalories per day About how many grams of fat day should he not exceed The DRV is based on less than 30 as fat so for this 4000 kcal example 4000 x 3 1200 kcals 1200 kcals 9 kcal gram 133 grams g government agency with label oversight the FDA food and drug administration h Ingredients on label listed in order by weight III Module 3 GI system a Portal vein A large vein that collects blood from the intestine and delivers it to the liver b most digestion and absorption in the small intestine most digestive enzymes produced by pancreas and small intestine c Sphincters definition names and locations The flow of chyme or feces is controlled by specialized muscles that form rings around the entrance or exit of
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