Nutrition

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Nutrition

  1. 1. Moment of Zen
  2. 2. • Obesity• Heart disease & Arteriolosclerosis• Diabetes• Genetically modified foods• Artificial sweeteners• DietsNutritionNutrition
  3. 3. Figure 24.1bRed meat, butter:use sparinglyVegetables inabundanceWhole-grainfoods atmost mealsDaily excercise and weight control(b) Healthy eating pyramidDairy or calciumsupplement: 1–2 servingsWhite rice, white bread,potatoes, pasta, sweets:use sparinglyFish, poultry, eggs:0–2 servingsNuts, legumes:1–3 servingsFruits:2–3 servingsPlant oilsat mostmeals
  4. 4. Figure 24.1a(a) USDA food guide pyramidGrainsVegetablesFruitsMeat andbeansOilsMilk
  5. 5. What are nutrients?Essential substances that your bodyneeds in order to grow and stay healthyWhat is a Nutrient?
  6. 6. Nutrients• Some provide energy.• All help build cells and tissues,regulate bodily processes suchas breathing.• No single food supplies all thenutrients the body needs tofunction.
  7. 7. Healthy Diets RequireHealthy Diets RequireMacronutrients• Water• Amino Acids and Proteins• Lipids• CarbohydratesMicronutrients• Vitamins (B, C, A, D, E, K)• Minerals (Fe, Ca, P, Na, K)Six categories of nutrients:
  8. 8. WaterWaterSolvent in which the chemistry of life occursSolvent in which the chemistry of life occurs• cell chemistry occurs in an aqueous mediumcell chemistry occurs in an aqueous medium• water carries essential nutrients to cellswater carries essential nutrients to cells• water carries metabolic wastes away from cellswater carries metabolic wastes away from cells• hydrolysis & dehydration reactionhydrolysis & dehydration reaction• stabilizes body tempstabilizes body temp
  9. 9. CarbohydratesCarbohydratesEnergy Metabolism• Glucose is the fuel used by cells tomake ATP–Neurons and RBCs rely almost entirelyupon glucose–Excess glucose is converted to glycogenor fat and stored
  10. 10. CarbohydratesDietary sources• Starch (complex carbohydrates) in grainsand vegetables• Sugars in fruits, sugarcane, sugar beets,honey and milk• Insoluble fiber: cellulose in vegetables;provides roughage• Soluble fiber: pectin in apples and citrusfruits; reduces blood cholesterol levels
  11. 11. CarbohydratesDietary requirements• Minimum 100 g/day to maintain adequateblood glucose levels• Recommended minimum 130 g/day• Recommended intake: 45–65% of totalcalorie intake; mostly complexcarbohydrates
  12. 12. CarbohydratesCarbohydratesDietary Fiber• water-insoluble fiber adds bulk to fecalmatter facilitating its passage through andelimination from the digestive system• water-soluble fiber may absorb dietarycholesterol, reducing its absorption by thedigestion tract
  13. 13. Wheat Seed
  14. 14. LipidsDietary sources• Triglycerides– Saturated fats in meat, dairy foods, andtropical oils– Unsaturated fats in seeds, nuts, olive oil,and most vegetable oils• Cholesterol in egg yolk, meats, organmeats, shellfish, and milk products
  15. 15. LipidsEssential fatty acids• Linoleic and linolenic acid, found in mostvegetable oils• Must be ingested
  16. 16. LipidsEssential uses of lipids in the body• Help absorb fat-soluble vitamins• Major fuel of hepatocytes and skeletalmuscle• Phospholipids are essential in myelinsheaths and all cell membranes
  17. 17. LipidsFunctions of fatty deposits (adiposetissue)• Protective cushions around body organs• Insulating layer beneath the skin• Concentrated source of energy
  18. 18. LipidsRegulatory functions of prostaglandins• Smooth muscle contraction• Control of blood pressure• InflammationFunctions of cholesterol• Stabilizes membranes• Precursor of bile salts and steroidhormones
  19. 19. LipidsDietary requirements suggested by theAmerican Heart Association• Fats should represent 30% or less of totalcaloric intake• Saturated fats should be limited to 10% orless of total fat intake• Daily cholesterol intake should be no morethan 300 mg
  20. 20. Pathways of Lipid Metabolism
  21. 21. AtherosclerosisAtherosclerosisnormalnormal diseaseddiseased
  22. 22. • Cholesterol: <175 mg/dl• Triglycerides: blood fats, 30-175mg/dl• HDL: Good cholesterol, > 35mg/dl• LDL: Bad Cholesterol, <130mg/dl• Chol/HDL ratio: < 4.5 indicatesheart diseaseYour Cholesterol LevelYour Cholesterol Level
  23. 23. Lowering Your Cholesterol LevelLowering Your Cholesterol Level• Eat healthy• Exercise• Lose wt.• Quit smoking• 1 glass of wine or beer• Medications (Lipitor)
  24. 24. ProteinsProteins• Enzymes• Structural proteins (shape andform of cells and tissues)• Hormones• Immunoglobulins (antibodies)
  25. 25. Essential AminoEssential AminoAcidsAcids• Tryptophan• Methionine• Valine• Threonine• Phenylalanine• Leucine• Isoleucine• Lysine• Arginine• Histidine(infants)
  26. 26. ProteinsDietary sources• Eggs, milk, fish, and most meats containcomplete proteins• Legumes, nuts, and cereals containincomplete proteins (lack some essentialamino acids)• Legumes and cereals together contain allessential amino acids
  27. 27. ProteinsUses• Structural materials: keratin, collagen,elastin, muscle proteins• Most functional molecules: enzymes, somehormones
  28. 28. ProteinsUse of amino acids in the body1. All-or-none rule– All amino acids needed must be present forprotein synthesis to occur2. Adequacy of caloric intake– Protein will be used as fuel if there isinsufficient carbohydrate or fat available
  29. 29. Proteins3. Nitrogen balance– State where the rate of protein synthesisequals the rate of breakdown and loss– Positive if synthesis exceeds breakdown(normal in children and tissue repair)– Negative if breakdown exceeds synthesis (e.g.,stress, burns, infection, or injury)
  30. 30. Proteins4. Hormonal controls– Anabolic hormones (GH, sex hormones)accelerate protein synthesis
  31. 31. Complete ProteinsComplete ProteinsVersusVersusIncomplete ProteinsIncomplete Proteins
  32. 32. Vegetarian diet may result in proteinVegetarian diet may result in proteindeficiencydeficiencyNeed essential amino acidsNeed essential amino acids• beansbeans →→ lysine & isoleucinelysine & isoleucine• corncorn →→ tryptophan & methioninetryptophan & methionine
  33. 33. TransaminationTransamination
  34. 34. VitaminsVitaminsOrganic compounds needed by the bodyin small, but essential amountsCannot be synthesized by the body insufficient amountsFunction in a variety of ways in metabolicreactionsThirteen known vitamins
  35. 35. Water-Soluble VitaminsWater-Soluble VitaminsVersusVersusWater-Insoluble VitaminsWater-Insoluble Vitamins
  36. 36. Water-SolubleWater-SolubleVitaminsVitaminsPantothenic acidBiotinB12 (cyanocobalamin)Folic acidC (ascorbic acid)B1 (thiamin)B2 (riboflavin)NiacinB6 (pyridoxine)
  37. 37. Water-InsolubleWater-InsolubleVitaminsVitaminsA (retinol)DEK
  38. 38. MineralsMineralsEssential inorganic elementsInvolved in a variety ofmetabolic processesMajor minerals versus traceminerals
  39. 39. Major MineralsMajor MineralsCalciumPhosphorusMagnesiumSodiumPotassiumChlorine
  40. 40. TraceTraceMineralsMineralsIronIodineFluorideZincCopperManganeseCobaltSeleniumChromium
  41. 41. An animal whose diet is missing one orAn animal whose diet is missing one ormore essential nutrients.more essential nutrients.Giraffe eats bone to get phosphorus nutrientMalnourishmentGiraffe eats bone to getphosphorus nutrient
  42. 42. Impaired cognitiveImpaired cognitivedevelopmentdevelopmentWon’t attain full heightWon’t attain full heightMore susceptible to diseaseMore susceptible to diseaseand infectionand infectionMalnourishment
  43. 43. • Approximately 24 millionpeople in the US havediabetes (10%)• Another 16 million havea condition now knownas prediabetesDiabetes Epidemic
  44. 44. Race: Native Hawaiians, Filipinos,Japanese, and Pacific IslandersPopulation: 100,000 with diabetesand 25,000 unreportedTrend: by 2050 years 33% will haveType IIDiabetes in Hawaii
  45. 45. Blood Sugar LevelsHomeostasis via Negative Feedback
  46. 46. Traditional Food in Hawaiivs
  47. 47. Diabetes MellitusDiabetes Mellitus
  48. 48. Type I Diabeteshyposecretion of insulininsulin dependantjuvenile onsetType II Diabeteslate onset (adult)insensitivity of cells to insulinmanage by exercise & diet
  49. 49. • sugar in blood and urine• urinate too often and produce toomuch urine• Too thirsty• Too hungrySymptoms (Type I):
  50. 50. • Arteriosclerosis• Cardiovascular problems- Heart disease- Stroke- High blood pressure• Gangrene• Blindness• Kidney damageComplications
  51. 51. • Insulin replacement• Pancreas transplant• Pancreatic cell transplant• Fetal pancreatic islet cell transplantTreatment:
  52. 52. 2010: U.S. spends $170 Billion AnnuallyPer Person:• Individuals with diabetes:$13,243/year• Individuals without diabetes:$2,560/yearCost $$$$
  53. 53. Obesity may be gene relatedObesity may be gene relatedLeptinLeptin− ↑↑ leptin levelsleptin levels ↓↓ appetiteappetite- loss of body fatloss of body fat ↓↓ leptin levels andleptin levels and ↑↑ appetiteappetiteand wt gainand wt gainpotential medications for obesitypotential medications for obesity
  54. 54. Here are the top 5 obese countries:• United States (34% of adults wereoverweight in 2008)• Mexico (30% in 2006)• New Zealand (27% in 2007)• Australia (25% in 2007)• United Kingdom (25% in 2008)Lowest: Japan & Korea 3.2%ObesityObesity
  55. 55. Genetically Modified FoodsGenetically Modified FoodsExperts say 60% to 70% of processedfoods on U.S. grocery shelves havegenetically modified ingredients.Common GM crops:• Soybeans• Corn• Cotton
  56. 56. Genetically Modified FoodsGenetically Modified FoodsConsCons• Introducing allergens and toxins to food• Accidental cross pollination• Antibiotic resistance• Creation of "super" weeds and otherenvironmental risks
  57. 57. Genetically Modified FoodsGenetically Modified FoodsProsPros• Increased pest and disease resistance• Grow food in harsh climate• Increased food supply (more food/acre)• More nutritional value• Make drugsRing spot virus
  58. 58. Artificial SweetenersArtificial Sweeteners• Reduced calories• Reduce tooth decay• Diabetes• Lower cost
  59. 59. Artificial SweetenersArtificial Sweeteners• Acesulfame potassium (Sunett, SweetOne)• Aspartame (Equal, NutraSweet)• Neotame• Saccharin (SugarTwin, SweetN Low)• Sucralose (Splenda)
  60. 60. Natural SweetenersNatural Sweeteners• Agave• Corn syrup• Honey• Maple syrup• Sugar cane• Stevia
  61. 61. Aim for Fitness1. Aim for a healthyweight
  62. 62. 2. Be physically active each day
  63. 63. Build a Healthy Base3. Let the pyramid guide yourchoices4. Choose a variety of grainsdaily, especially whole grains5. Choose a variety of fruits andvegetables daily.6. Keep food safe to eat.
  64. 64. Choose Sensibly7. Choose a diet that is low in saturatedfat and cholesterol and moderate in totalfat8. Choose beverages and foodsto moderate your intake ofsugars9. Choose and prepare food with lesssalt10. If you drink alcoholicbeverages do so in moderation
  65. 65. All organisms must maintain aconstant internal environment tofunction properly• Temperature• pH• ion levels• HormonesHomeostasis
  66. 66. Heat and Energy BalanceHeat- calories or kilocaloriesMetabolic Rate- measure in BMR
  67. 67. What is a calorie?The energy obtained fromcarbohydrates, proteins, andfats is measured in units calledcalories.Calories
  68. 68. Body Temperature HomeostasisHeat Production:• Exercise• Hormones• Nervous system• Body temperature• Ingestion of food• Age• Other factors
  69. 69. Body TempBody TempRegulationRegulation
  70. 70. Heat exchange by:• Conduction- transfer of heat between objects indirect contact with each other• Convection- heat is conducted away from anobject of high temp to low temp- Rate varies with different materials• Radiation- transfers heat between objects not indirect contact- sun energy• Evaporation- change of liquid to vapor- coolingFour physical processes accountfor heat gain or loss
  71. 71. Heat exchange between an organismand its environment
  72. 72. INQUIRY1. What are nutrients that the body needs but can’tsynthesize on its own called?2. Which cells of the body, under normalcircumstances, must have energy in the form ofglucose in order to survive?3. How does the body make use of dietarycholesterol?4. What is an incomplete protein?5. What trace element is necessary for woundhealing?6. Neural tube defects are easily prevented by theadequate intake of ____ by pregnant mothers.7. What carbohydrate can be found in a steak?8. Hemorrhaging could occur because of lack ofsufficient vitamin _____.

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