1. ‘ M E A T ’ , ‘ M I L K A N D M I L K - B A S E D
P R O D U C T S ( D A I R Y ) ’ A N D ‘ E X T R A S ’
XNB151 Food
and Nutrition
Rembrandt,theFlayedOx
Francisco Goya, Still Life
with Slices of Salmon, 1808 Arcimboldo, The Water
Vermeer, The Milkmaid
Velazquez, Old Woman Frying
Eggs

2. Meat & meat alternatives

4. Key nutrients obtained from meat and meat alternatives
 Macronutrients
 Protein- high biological value in meat & fish i.e. A good range of
essential amino acids
 Fats
 Omega 3 fats (some types of fish only)
 Fibre (nuts & seeds only)
Fat content of fish varies from 0.5
to 15% depending on season and
factors such as water temperature

5. 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 in
animals
Liver and kidney
especially rich sources

6. Proposed Benefits Proposed Risks
 Paleolithic diets rationale
based on evidence that
Homo sapiens evolved
on a relatively high-meat
diet
 Good source of pre-
formed arachidonic acid
 Most bioavailable source
of many minerals
 Satiating
 Saturated fat and cholesterol
 Nitrites and charring linked
with cancer
 Inconsistent link between
high meat intake & colo-rectal
cancer
 Evidence for high processed
meat intake & colo-rectal
cancer
 Displacement of vegetables
 Bovine Spongiform
Encephalopathy →
Creutzfeldt-Jakob Disease
Meat and Health

7. Benefits Risks
 Mainly related to
omega 3 content (to be
discussed later in this
lecture)
 Mercury
 Tapeworms if
undercooked
 Bacterial spoilage
 Tetradoxin poisoning
Fish and Health

8. Benefits Risks
 Nut consumption 5+
times per week may
have reduced risk of
CVD
 Important source of
healthy fats
 Important energy &
nutrient source
 Weight gain
 Allergy (1% of persons)
Nuts and Health
http://www.nutriset.fr/en/product-range/produit-par-
produit/plumpynut-ready-to-use-therapeutic-food-
rutf.html

9. Milk and milk-based products

10. Recommended Dairy servings for Australians (AGHE)

11. Key nutrients obtained from Milk & Milk-Products
 Macronutrients
 Protein
 Carbohydrate
 Micronutrients
 Calcium
 Phosphorous
 Potassium
 Riboflavin
 Vitamin D (especially fortified)

12. Benefits Risks
 Increased bone mass
and reduced
osteoporosis
 Reduced risk of colon
cancer
 Non-cariogenic
 Nutrient rich
 If full fat versions →↑
LDL cholesterol
Milk and Health

13. Roles of key nutrients from meat & meat
alternatives and milk and milk-based products

14. Protein - Basic structure
 3-D strands composed of hundreds of amino
acids linked by peptide bonds (i.e. amino acids
join to form proteins)
 ~½ are essential or indispensable
 essential in the diet as cannot be made in the body
Proteins
Peptide bond to form
chains (protein structure
depends on order of
amino acids

15. ProteinCell membrane
componentSelective
transport into/
out of cells
Enzymes
Enable
chemical
reactions
Haemoglobin
Oxygen
delivery to
tissuesAlbumin
Osmotic
pressure
& water
balance
Transferrin
Iron
transport
from gut to
bone
marrow/
other tissues
Nucleoprotein
Stabilise
nucleic acid
structure
Contractile
protein
(muscle)
Muscle
contraction
& movement
Role of proteins in the body

16. Protein deficiency
 Deficiency - usually with inadequate energy -
malnutrition, infection, anaemia, oedema, kwashiork
or

17. High protein intakes
High protein diets for weight loss
Extreme approaches  very
low CHO
Moderate approaches
e.g. CSIRO Total Wellbeing Diet
Loss of fluid rather than fat
(especially in short term)
Consider lack of nutrients e.g.
fibre, vits & mins, not sustainable
Promotes moderate
consumption of nutritious
wholegrains & low GI CHO-
rich foods as well as high
protein
http://www.csiro.au/?sc_itemid={1873A95F-
6935-44F6-86A8-4D94E248F184}

18. High protein diets
Advantages
 Prevent muscle
wasting when energy
is restricted
 Improve satiety
 Easier compliance for
some (at least short-
term)
 As effective as low fat
for weight loss
 Improved blood
glucose control &
metabolic syndrome
Disadvantages
 High in red meat:
(opposing view to
cancer council)
 Environmental impact
(non-meat protein
sources) cost
 Unsure of long-term
effects, consider kidney
function, osteoporosis
 Increased calcium
excretion
 Long term compliance

19. Recommended Protein Intakes
RDI
 Men 19-70 = 0.84g/kg – ‘average’ 64g/d
 Women 19-70 = 0.75g/kg – ‘average’ 46g/d
AMDR
 Men & Women 15 to 25%
• Requirements vary for age >70y, 2nd & 3rd trimesters
of pregnancy & lactation
• Infants & children have age-specific requirements

20. Absorption of iron
Factors
enhancing
absorption
• Vitamin C
• Haem iron (↑s
absorption non-haem
iron)
• Cooking
Factors reducing
absorption
• Soy protein
• Tannins
(tea, coffee, wines)
• Phytates/ fibre
(wholegrains)
• Calcium/ phosphorus
(dairy)

21. Role of iron in the body
Iron Haemoglobin
Oxygen
transport in
blood
Myoglobin
Oxygen store
in muscle
Metalloproteins
Ferritin
Iron
storage
Transferrin Iron transport
Cytochromes
Oxidation-reduction
reactions

22. Iron Deficiency Symptoms
• Fatigue (inability to mobilise O2)
• Decline in cognitive function
- inability to concentrate (adult)/ intellectual
impairment (child)
• Susceptibility to infections (impaired immunity)
• Decreased pain threshold
• Impaired heat regulation (can't adapt to cold) (
thyroxine)

23. Iron … excess
 ≤0.5% Caucasian
population at risk of
hereditary
haemochromatosis
 Fe often interacts with
other minerals
 Fe & Ca compete for
absorption
 Fe poisoning in infants
 ‘Mummy’s lollies’ i.e. iron
tablets are little & red

24. Iron requirements
RDIs
 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 8mg
If iron deficiency anaemia diagnosed, iron supplements often medically
recommended
• Common side effects e.g. constipation

25. Calcium
Calcium is ~2% of total body weight
99.6% deposited as
calcium phosphate
crystals in bone
Strengthens bones & teeth
99.1% in intra- &
extracellular fluids
• Contraction/ relaxation
muscles
• Blood clotting
• Enzyme function
• Nervous system
messagesFood sources high
in calcium
include...
Milk, yogurt &
especially cheese
Fish with bones

26. Calcium absorption
 Only ~30-40% absorbed in most Australian
diets
Combinations
that facilitate
absorption
Sugars
(especially
lactose)
Protein (in
milk & cheese)
Combinations
that inhibit
absorption
Dietary fibre
Oxalates
(spinach, beetroot, eggp
lant, celery, leafy
greens, squash etc)
Increases
solubility
Decreases
solubility
• s transit time
• stimulate
bacterial growth &
bacteria bind
minerals
• Phytates bind Ca

27. 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

28. Calcium requirements
RDIs
 1 year+ 500-1300mg
(varies according to age/gender)
 Adults 1000mg/day
 Older women >50yrs 1300 mg/day
 Older men >70yrs 1300mg/day
Food preferred in place of supplementation
• supplementation may be helpful if at risk osteoporosis – consult doctor
• excess can cause GIT upsets

29. Vitamin D
 80 to 90% of
requirements obtained
from sunlight
 Available from a limited
range of foods
 Deficiency/insufficiency
more widespread than
previously thought
 Traditionally main role in
calcium absorption &
healthy bones
 More recent research
indicates a much wider
role in health & disease
Main Dietary Sources
Tuna, salmon, sardines, eggs, fortified milk, cheese, margarine,
RoyLichtenstein,
SinkingSun,1964

30. Extras

31. Recommended ‘extras’ servings for Australians (AGHE)

32. Key nutrients obtained from extras
 Macronutrients
 Fat
 Carbohydrate
 Alcohol
 Micronutrients
 Sodium
BY DEFINITION EXTRAS ARE NOT ESSENTIAL FOR
ANY OF THESE NUTRIENTS – ALL CAN BE OBTAINED
FROM OTHER SOURCES

33. Extras – good or bad?
vs
Some ‘extras’ may
provide health benefits
over others
INCLUDING
MODERATION
SOMETIMES
Everything in
moderation
Mostly a concern if →excess energy intake
&/or replacing foods with essential nutrients

34. Effects of Key Nutrients From Extras

35. Fats & Lipids
saturated monounsaturated polyunsaturated
point of
unsaturation
points of
unsaturation
Effect on blood cholesterol levels vary between fats

37. Beneficial fats
Monounsaturated FAs
Decrease total
& LDL
cholesterol &
TGs
Found in
• Monounsaturated margarine spreads
• Monounsaturated oils e.g. olive, canola &
peanut oils
• Nuts e.g. peanuts, cashews & almonds
• Seeds
• Avocado

38. Beneficial fats
Polyunsaturated FAs
Omega-6
Omega-3
Decrease total & LDL
cholesterol &
triglycerides
Decrease triglycerides
Increase HDL-cholesterol
Anti-platelet effects – lower risk of thrombosis
Decrease some inflammatory responses
Lower blood pressure
Found in
• Seeds & oils –
sunflower, safflower, soybean, sesa
me, grapeseed
• Polyunsat. margarine spreads &
oils
• Walnuts, brazil nuts, pinenuts
Found in
• Oils from
soybean, canola, mustard seed
• Marine sources (oily fish) e.g.
alantic
salmon, sardines, tuna, silver
perch, bass, herring, rainbow
trout, anchovy

39. Detrimental fats
Saturated fats Trans- fats
Found in
• Fatty meats
• Full fat dairy products
• Butter
• Coconut & palm oil
• Deep fried take-away foods
• Commercially baked products
Increases
total & LDL
cholesterol
Found in
• Small amounts in dairy
products, beef, veal, lamb &
mutton
• Baked goods
• pies & pastries
• cakes, biscuits & buns
Increases
total & LDL
cholesterol
May
Decreases
HDL
cholesterol

40. 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

41. Excess energy is stored as fat (triglycerides)
 Stored as fat
 Energy reserves for muscles
 Insulation
 thermal
 mechanical

42. Recommended intake of fat
 No Recommended Dietary Intake for total fat intake
 Recommendation of 20-35% of total energy with
saturated & trans fats to be no more than 10% of
energy
i.e. saturated & trans one third of total fat

43. Deficiency Excess
 Inadequate intake of
essential fatty acids -
linoleic, α-linolenic
 Effect on usual fat
functions
 Inadequate absorption
fat soluble vitamins
 Inadequate energy 
protein breakdown
 Weight gain, overweight/
obesity  development
chronic lifestyle related
disease
 Excess saturated/ trans
increased cardiac risk
Thrombus
Inflammatory
Cells
Smooth
Muscle Cells
Fats & Lipids

44. Benefits Disadvantages
 In small amounts
 Reduces risk of heart
disease
 some beverages
contain
phytochemicals
 Inappropriate/excessive use
of
 overweight
 numerous nutrient
deficiencies
 B vitamins
 general malnutrition
 digestive upsets
 raised plasma triglycerides
 foetal alcohol syndrome
 long term liver & brain disease
 accidental & violence related
hospital admissions
 risky behaviour
 social & psychological harm
Alcohol

45. NHMRC 2009 Alcohol Guidelines
Guideline 1:
For healthy men and women, drinking no
more than two standard drinks on any day
reduces the lifetime risk of harm from
alcohol-related disease or injury.
Guideline 2:
For healthy men and women, drinking no
more than four standard drinks on a single
occasion reduces the risk of alcohol related
injury arising from that occasion.

46. NHMRC 2009 Alcohol Guidelines
Guideline 3:
3A Parents and carers should be advised that
children under 15 years of age are at the
greatest risk of harm from drinking and that
for this age group, not drinking alcohol is
especially important.
3B For young people aged 15–17 years the
safest option is to delay the initiation of
drinking for as long as possible.

47. NHMRC 2009 Alcohol Guidelines
Guideline 4:
4A For women who are pregnant or planning
a pregnancy, not drinking is the safest
option.
4B For women who are breastfeeding, not
drinking is the safest option.

48. Sodium
 Kidneys regulate sodium levels
 Sweat loss only relevant in prolonged & unaccustomed heavy
exercise
 Found in many foods
 Traces  wholegrains, meat & dairy products
 Large amounts processed foods
Sodium
Maintenance of correct
volume of circulating
blood & tissue fluids
Role in electrical activity
of muscles & nerves
Control of water
movements between
muscles and tissues

49. Deficiency Excess
 Rare but can be
dangerous
 losses through
urine, perspiration, vomiting &
diarrhoea
 Excessive loss can lead to
muscle
cramps, nausea, vomiting
& dizziness  eventually
shock, coma & death
 main causes
 acute gastroenteritis
 severe sweating
 water intoxication (from
drinking too much water)
 Mainly thought to
elevate blood pressure &
thus  risk CVD & renal
disease
NOTE: not all
hypertension is due to
Na

50. 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)

51. 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

52. Summary of health effects of meat, dairy and extras
Meat
Dairy
Extras
Iron
Protein
Fat
Vitamin E
Retinol
(discussed in
Week 7)
Saturated
Monounsaturated
Polyunsaturated
Trans
↑d LDL
↑d HDL
↓d LDL
↓d HDL
Selective transport
into/ out of cells
Oxygen delivery/
storage/ transport
Osmotic pressure &
water balance
Iron transport/
storage
Stabilise nucleic acid
structure
Muscle contraction &
movement
Calcium
Strengthens bones &
teeth
Contraction/
relaxation muscles
Blood clotting
Enzyme function
Nervous system
messages
↓d risk heart disease
↑d risk heart disease
Sodium
↑d blood
pressure