NFSC100 January 2 2014 The Science of Nutrition Many actions in the body Nutrition definition The science of foods and nutrients they contain The quality of your daily diet affects your health and risk of disease Over a long period of time it will have a detrimental affect on your body We learn a lot of information from the media Why is nutrition classified as a science We use the scientific method New findings must be repeated before they can be considered valid Go over scientific method observations formulate hypothesis test hypothesis evaluate study results compare to original hypothesis Eventually it can become a theory Four types of studies Case studies individual epidemiological studies populations Intervention clinical studies experimental v control Laboratory pre clinical studies animal models Food Labeling Why labeling New food labels tell a lot about food Nutrition Labeling and education Act NLEA 1990 Ingredients are given to you in descending order of weight Go over everything the label must contain serving size calories and calories from fat percent of fat Daily Value Indicates how much of a specific nutrient one serving of food contains compared to daily nutrient 5 10 20 Rule for daily Value Below 5 is considered low or poor source 10 19 is considered a good source of the daily value per serving Above 20 is considered high or an excellent source Different depending upon whether the nutrient is beneficial or detrimental to health Types of Claims in textbook Nutrient Content Claims Tables 2 6 levels of nutrients terms are now defined free low reduced etc Health Claims Table 2 7 Already approved by FDA based on scientific evidence Structure Function Claims Need additional scientific evidence and FDA approval or state that FDA has not evaluated the claim Nutrient Claims Calorie Free less than 5 calories per serving Low Calorie Less than or equal to 40 calories per serving Reduced Calorie at least 25 lower in calories than reference food Sodium Free Low Sodium Fat free Low fat Reduced Health Claims Is in expressed or implied statement in food labeling about the relationship of a food substance to a disease or health related condition Examples Calcium and osteoporosis Sodium and hypertension Dietary fat and cancer Fiber and Cancer Fruits vegis and grain products and heart disease Nutrition and Physiology Body Organization Cells Tissues Organs Systems Organism Nucleus Control Center Contains DNA Mitochondrion Power plant supply ATP Golgi Complex Packaging center Ribosome Protein synthesis Free or on ER How do cells interact with nutrients The cell membrane is made up on phospolipids ER Smooth Cholesterol synthesis and fat metabolism Rough ER protein production Plasma Membrane Regulates what enter and leaves the cell Lysosome Housekeeper Membrane receptors Protein on outer surface or cell or nuclear membrane that detects Tissue group of cells performing a specialized function Epithelial Connective Muscular Nervous Organ group of tissues performing a specialized function Examples are brain heart and liver Integumentary System Skin hair nails sweat glands Skeletal system Bones joints ligaments and cartiglage Muscular system Skeletal muscle that enables the body to move high energy and nutrient Nervous system Brain spinal cord nerves and sesory receptors Endocrine System Flands including pituitary thyroid adrenal pancreas Helps produce hormones that secrete and help control the bodies activites Cardiovascular system Heart blood vessels blood Lymphatic system lymph vessels lymph nodes and organs including spleen and tonsils Respitory system lunds and respitory passages Digestive system mouth esophagus stomach and intestines Urinary systemL kidneys bladder ducts Reproductive system Gonads gentials Immune system lymphocytes and phagocytes The Digestive System Digestion is the breakdown of food components into small enough structures to facilitate absorption The key to understanding digestion is that it s both a mechanical and chemical process that takes place at the same time Mechanical Chewing crunching breaking things apart Chemical enzymes The Mouth Mechanial chewing Chemical saliva from 3 pairs of salivary glands Saliva moistens thefood making it easier to dissolve Starch amylase small polysaccharides oligosaccharides The salivary enzyme lipase beings digestion of fat triglycerides Triglycerides lipase fatty acids mono and di glycerides The Esophagus Mechanical peristaltic movement Chemical none The digestive system In stomach produces HCL and pepsin And liver produces bile which is stored and concentrated in the gullbladder The Stomach uncoils protein stands and activates stomach enzyes Pepsin proteolytic enzyme protein lysing Grinding and churning of food with secretion converts ood into liquid mass On quiz peridal cells Look at bottom right on picture The majority of the digestion takes place is in the small intestine Chemical Digestion Sugar and Starch Absorption of Digestion of products Fats Small fatty acids enter blood Excretory Products Feces and Urine Carbohydrates Glucose fructose and galactose enter the blood stream
View Full Document
Unlocking...