NFSC100January 2, 2014The Science of Nutrition: Nutrition definition: The science of foods and nutrients they containMany actions in the body. 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 source10-19% is considered a good source of the daily value per servingAbove 20% is considered high, or an excellent source.Different depending upon whether the nutrient is beneficial or detrimental to health. Types of Claims: in textbookNutrient 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, orstate 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 FreeLow SodiumFat free Low fatReduced, “Health Claims” Is in expressed or implied statement in food labeling about the relationship of a foodsubstance 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 diseaseNutrition and Physiology:Body OrganizationCells TissuesOrgansSystemsOrganismNucleus-Control Center/Contains DNAMitochondrion-Power plant/supply ATPGolgi Complex- Packaging centerRibosome-Protein synthesis/ Free or on ERHow do cells interact with nutrients-The cell membrane is made up on phospolipids. ER- Smooth(Cholesterol synthesis and fat metabolism)Rough ER- protein productionPlasma Membrane-Regulates what enter and leaves the cellLysosome-HousekeeperMembrane 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 cartiglageMuscular system: Skeletal muscle that enables the body to move, high energy and nutrientNervous 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, gentialsImmune system: lymphocytes and phagocytesThe 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 apartChemical: 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 pictureThe majority of the digestion takes place is in the small intestine. Chemical Digestion: Sugar and StarchAbsorption of Digestion of products: Fats(Small fatty acids enter blood)Carbohydrates(Glucose, fructose,and galactose enter the blood stream) . Excretory Products: Feces and
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