XNB151 Week 8 Meat, dairy and extras


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XNB151 Week 8 Meat, dairy and extras

  1. 1. ‘ M E A T ’ , ‘ M I L K A N D M I L K - B A S E DP R O D U C T S ( D A I R Y ) ’ A N D ‘ E X T R A S ’XNB151 Foodand NutritionRembrandt,theFlayedOxFrancisco Goya, Still Lifewith Slices of Salmon, 1808 Arcimboldo, The WaterVermeer, The MilkmaidVelazquez, Old Woman FryingEggs
  2. 2. Meat & meat alternatives
  3. 3. Key nutrients obtained from meat and meat alternatives Macronutrients Protein- high biological value in meat & fish i.e. A good range ofessential amino acids Fats Omega 3 fats (some types of fish only) Fibre (nuts & seeds only)Fat content of fish varies from 0.5to 15% depending on season andfactors such as water temperature
  4. 4. Key nutrients obtained from meat and meat alternatives Minerals Iron Zinc (Oysters & crab especially rich) Potassium Phosphorous Iodine (fish) Selenium (fish & nuts) Fluoride (fish) Vitamins Vitamin B12 (animal products only) Retinol (Vitamin A) (animal products only) Vitamin D (Salmon, tuna, sardines, fish liver & eggs only) Thiamin, niacin, riboflavin (B vitamins)Much higher bioavailability inanimalsLiver and kidneyespecially rich sources
  5. 5. Proposed Benefits Proposed Risks Paleolithic diets rationalebased on evidence thatHomo sapiens evolvedon a relatively high-meatdiet Good source of pre-formed arachidonic acid Most bioavailable sourceof many minerals Satiating Saturated fat and cholesterol Nitrites and charring linkedwith cancer Inconsistent link betweenhigh meat intake & colo-rectalcancer Evidence for high processedmeat intake & colo-rectalcancer Displacement of vegetables Bovine SpongiformEncephalopathy →Creutzfeldt-Jakob DiseaseMeat and Health
  6. 6. Benefits Risks Mainly related toomega 3 content (to bediscussed later in thislecture) Mercury Tapeworms ifundercooked Bacterial spoilage Tetradoxin poisoningFish and Health
  7. 7. Benefits Risks Nut consumption 5+times per week mayhave reduced risk ofCVD Important source ofhealthy fats Important energy &nutrient source Weight gain Allergy (1% of persons)Nuts and Healthhttp://www.nutriset.fr/en/product-range/produit-par-produit/plumpynut-ready-to-use-therapeutic-food-rutf.html
  8. 8. Milk and milk-based products
  9. 9. Recommended Dairy servings for Australians (AGHE)
  10. 10. Key nutrients obtained from Milk & Milk-Products Macronutrients Protein Carbohydrate Micronutrients Calcium Phosphorous Potassium Riboflavin Vitamin D (especially fortified)
  11. 11. Benefits Risks Increased bone massand reducedosteoporosis Reduced risk of coloncancer Non-cariogenic Nutrient rich If full fat versions →↑LDL cholesterolMilk and Health
  12. 12. Roles of key nutrients from meat & meatalternatives and milk and milk-based products
  13. 13. Protein - Basic structure 3-D strands composed of hundreds of aminoacids linked by peptide bonds (i.e. amino acidsjoin to form proteins) ~½ are essential or indispensable essential in the diet as cannot be made in the bodyProteinsPeptide bond to formchains (protein structuredepends on order ofamino acids
  14. 14. ProteinCell membranecomponentSelectivetransport into/out of cellsEnzymesEnablechemicalreactionsHaemoglobinOxygendelivery totissuesAlbuminOsmoticpressure& waterbalanceTransferrinIrontransportfrom gut tobonemarrow/other tissuesNucleoproteinStabilisenucleic acidstructureContractileprotein(muscle)Musclecontraction& movementRole of proteins in the body
  15. 15. Protein deficiency Deficiency - usually with inadequate energy -malnutrition, infection, anaemia, oedema, kwashiorkor
  16. 16. High protein intakesHigh protein diets for weight lossExtreme approaches  verylow CHOModerate approachese.g. CSIRO Total Wellbeing DietLoss of fluid rather than fat(especially in short term)Consider lack of nutrients e.g.fibre, vits & mins, not sustainablePromotes moderateconsumption of nutritiouswholegrains & low GI CHO-rich foods as well as highproteinhttp://www.csiro.au/?sc_itemid={1873A95F-6935-44F6-86A8-4D94E248F184}
  17. 17. High protein dietsAdvantages Prevent musclewasting when energyis restricted Improve satiety Easier compliance forsome (at least short-term) As effective as low fatfor weight loss Improved bloodglucose control &metabolic syndromeDisadvantages High in red meat:(opposing view tocancer council) Environmental impact(non-meat proteinsources) cost Unsure of long-termeffects, consider kidneyfunction, osteoporosis Increased calciumexcretion Long term compliance
  18. 18. Recommended Protein IntakesRDI Men 19-70 = 0.84g/kg – ‘average’ 64g/d Women 19-70 = 0.75g/kg – ‘average’ 46g/dAMDR Men & Women 15 to 25%• Requirements vary for age >70y, 2nd & 3rd trimestersof pregnancy & lactation• Infants & children have age-specific requirements
  19. 19. Absorption of ironFactorsenhancingabsorption• Vitamin C• Haem iron (↑sabsorption non-haemiron)• CookingFactors reducingabsorption• Soy protein• Tannins(tea, coffee, wines)• Phytates/ fibre(wholegrains)• Calcium/ phosphorus(dairy)
  20. 20. Role of iron in the bodyIron HaemoglobinOxygentransport inbloodMyoglobinOxygen storein muscleMetalloproteinsFerritinIronstorageTransferrin Iron transportCytochromesOxidation-reductionreactions
  21. 21. Iron Deficiency Symptoms• Fatigue (inability to mobilise O2)• Decline in cognitive function- inability to concentrate (adult)/ intellectualimpairment (child)• Susceptibility to infections (impaired immunity)• Decreased pain threshold• Impaired heat regulation (cant adapt to cold) (thyroxine)
  22. 22. Iron … excess ≤0.5% Caucasianpopulation at risk ofhereditaryhaemochromatosis Fe often interacts withother minerals Fe & Ca compete forabsorption Fe poisoning in infants ‘Mummy’s lollies’ i.e. irontablets are little & red
  23. 23. Iron requirementsRDIs 0-6 months, infants use body stores 6 months+ 8-18mg (varies according to) age/gender Women 19 to 50 years 18mg Women aged ≥ 51 years 8mg Pregnant women 27mg Men aged ≥19 years 8mgIf iron deficiency anaemia diagnosed, iron supplements often medicallyrecommended• Common side effects e.g. constipation
  24. 24. CalciumCalcium is ~2% of total body weight99.6% deposited ascalcium phosphatecrystals in boneStrengthens bones & teeth99.1% in intra- &extracellular fluids• Contraction/ relaxationmuscles• Blood clotting• Enzyme function• Nervous systemmessagesFood sources highin calciuminclude...Milk, yogurt &especially cheeseFish with bones
  25. 25. Calcium absorption Only ~30-40% absorbed in most AustraliandietsCombinationsthat facilitateabsorptionSugars(especiallylactose)Protein (inmilk & cheese)Combinationsthat inhibitabsorptionDietary fibreOxalates(spinach, beetroot, eggplant, celery, leafygreens, squash etc)IncreasessolubilityDecreasessolubility• s transit time• stimulatebacterial growth &bacteria bindminerals• Phytates bind Ca
  26. 26. Calcium deficiency• Decrease in bone density  brittle weak bones (Osteoporosis)• diet, exercise, body weight & genetics also affect development• peak bone mass ~30 years of age
  27. 27. Calcium requirementsRDIs 1 year+ 500-1300mg(varies according to age/gender) Adults 1000mg/day Older women >50yrs 1300 mg/day Older men >70yrs 1300mg/dayFood preferred in place of supplementation• supplementation may be helpful if at risk osteoporosis – consult doctor• excess can cause GIT upsets
  28. 28. Vitamin D 80 to 90% ofrequirements obtainedfrom sunlight Available from a limitedrange of foods Deficiency/insufficiencymore widespread thanpreviously thought Traditionally main role incalcium absorption &healthy bones More recent researchindicates a much widerrole in health & diseaseMain Dietary SourcesTuna, salmon, sardines, eggs, fortified milk, cheese, margarine,RoyLichtenstein,SinkingSun,1964
  29. 29. Extras
  30. 30. Recommended ‘extras’ servings for Australians (AGHE)
  31. 31. Key nutrients obtained from extras Macronutrients Fat Carbohydrate Alcohol Micronutrients SodiumBY DEFINITION EXTRAS ARE NOT ESSENTIAL FORANY OF THESE NUTRIENTS – ALL CAN BE OBTAINEDFROM OTHER SOURCES
  32. 32. Extras – good or bad?vsSome ‘extras’ mayprovide health benefitsover othersINCLUDINGMODERATIONSOMETIMESEverything inmoderationMostly a concern if →excess energy intake&/or replacing foods with essential nutrients
  33. 33. Effects of Key Nutrients From Extras
  34. 34. Fats & Lipidssaturated monounsaturated polyunsaturatedpoint ofunsaturationpoints ofunsaturationEffect on blood cholesterol levels vary between fats
  35. 35. Beneficial fatsMonounsaturated FAsDecrease total& LDLcholesterol &TGsFound in• Monounsaturated margarine spreads• Monounsaturated oils e.g. olive, canola &peanut oils• Nuts e.g. peanuts, cashews & almonds• Seeds• Avocado
  36. 36. Beneficial fatsPolyunsaturated FAsOmega-6Omega-3Decrease total & LDLcholesterol &triglyceridesDecrease triglyceridesIncrease HDL-cholesterolAnti-platelet effects – lower risk of thrombosisDecrease some inflammatory responsesLower blood pressureFound in• Seeds & oils –sunflower, safflower, soybean, sesame, grapeseed• Polyunsat. margarine spreads &oils• Walnuts, brazil nuts, pinenutsFound in• Oils fromsoybean, canola, mustard seed• Marine sources (oily fish) e.g.alanticsalmon, sardines, tuna, silverperch, bass, herring, rainbowtrout, anchovy
  37. 37. Detrimental fatsSaturated fats Trans- fatsFound in• Fatty meats• Full fat dairy products• Butter• Coconut & palm oil• Deep fried take-away foods• Commercially baked productsIncreasestotal & LDLcholesterolFound in• Small amounts in dairyproducts, beef, veal, lamb &mutton• Baked goods• pies & pastries• cakes, biscuits & bunsIncreasestotal & LDLcholesterolMayDecreasesHDLcholesterol
  38. 38. Functions of fat/fatty acids Important roles in body! Provide essential fatty acids & fat soluble vitamins protect internal organs, provide insulation membrane fluidity & structure cell division n-3 & n-6 affect formation of eicosanoids Metabolic role in regulating physiological processes (e.g.blood clotting, immunity, vascular tone) Functions in palatability of food an satiety
  39. 39. Excess energy is stored as fat (triglycerides) Stored as fat Energy reserves for muscles Insulation thermal mechanical
  40. 40. Recommended intake of fat No Recommended Dietary Intake for total fat intake Recommendation of 20-35% of total energy withsaturated & trans fats to be no more than 10% ofenergyi.e. saturated & trans one third of total fat
  41. 41. Deficiency Excess Inadequate intake ofessential fatty acids -linoleic, α-linolenic Effect on usual fatfunctions Inadequate absorptionfat soluble vitamins Inadequate energy protein breakdown Weight gain, overweight/obesity  developmentchronic lifestyle relateddisease Excess saturated/ transincreased cardiac riskThrombusInflammatoryCellsSmoothMuscle CellsFats & Lipids
  42. 42. Benefits Disadvantages In small amounts Reduces risk of heartdisease some beveragescontainphytochemicals Inappropriate/excessive useof overweight numerous nutrientdeficiencies B vitamins general malnutrition digestive upsets raised plasma triglycerides foetal alcohol syndrome long term liver & brain disease accidental & violence relatedhospital admissions risky behaviour social & psychological harmAlcohol
  43. 43. NHMRC 2009 Alcohol GuidelinesGuideline 1:For healthy men and women, drinking nomore than two standard drinks on any dayreduces the lifetime risk of harm fromalcohol-related disease or injury.Guideline 2:For healthy men and women, drinking nomore than four standard drinks on a singleoccasion reduces the risk of alcohol relatedinjury arising from that occasion.
  44. 44. NHMRC 2009 Alcohol GuidelinesGuideline 3:3A Parents and carers should be advised thatchildren under 15 years of age are at thegreatest risk of harm from drinking and thatfor this age group, not drinking alcohol isespecially important.3B For young people aged 15–17 years thesafest option is to delay the initiation ofdrinking for as long as possible.
  45. 45. NHMRC 2009 Alcohol GuidelinesGuideline 4:4A For women who are pregnant or planninga pregnancy, not drinking is the safestoption.4B For women who are breastfeeding, notdrinking is the safest option.
  46. 46. Sodium Kidneys regulate sodium levels Sweat loss only relevant in prolonged & unaccustomed heavyexercise Found in many foods Traces  wholegrains, meat & dairy products Large amounts processed foodsSodiumMaintenance of correctvolume of circulatingblood & tissue fluidsRole in electrical activityof muscles & nervesControl of watermovements betweenmuscles and tissues
  47. 47. Deficiency Excess Rare but can bedangerous losses throughurine, perspiration, vomiting &diarrhoea Excessive loss can lead tomusclecramps, nausea, vomiting& dizziness  eventuallyshock, coma & death main causes acute gastroenteritis severe sweating water intoxication (fromdrinking too much water) Mainly thought toelevate blood pressure &thus  risk CVD & renaldiseaseNOTE: not allhypertension is due toNa
  48. 48. Sodium requirements Adequate Intake Adults 20-40mmol/day (460-920mg/day) Upper level Adults 100 mmol/day (2300mg/day) Suggested Dietary Target Adults 70mmol/day (1600mg)
  49. 49. Reducing intake to avoid chronic disease Easiest effective methods?  high salt foods choose /low salt breads/cereals/products  processed foods avoid adding salt, use herbs & spices & fresh vegies for flavour
  50. 50. Summary of health effects of meat, dairy and extrasMeatDairyExtrasIronProteinFatVitamin ERetinol(discussed inWeek 7)SaturatedMonounsaturatedPolyunsaturatedTrans↑d LDL↑d HDL↓d LDL↓d HDLSelective transportinto/ out of cellsOxygen delivery/storage/ transportOsmotic pressure &water balanceIron transport/storageStabilise nucleic acidstructureMuscle contraction &movementCalciumStrengthens bones &teethContraction/relaxation musclesBlood clottingEnzyme functionNervous systemmessages↓d risk heart disease↑d risk heart diseaseSodium↑d bloodpressure