1. XNB151 Food and Nutrition
Breads & Cereals,
Fruits and
Vegetables

2. Some background information...
Core food groups
◦ Foods grouped into 5 key groups
 Breads & cereals
 Fruit
 Vegetables
 Meat & meat alternatives
 Milk & milk based products (Dairy)
◦ Recommendations for core foods based on
minimum amounts of food required for good
health

3. Background - Macronutrients
Required by the body in large amounts for
survival and growth (excepting alcohol)
Source of energy
Dietary manipulation central to
prevention/treatment of a number of
chronic conditions
(protein, fat, CHO, alcohol)

4. Background – Micronutrients: vitamins
 organic compound, natural component of food
 essential for physiological function, small amounts (mg,
µg/d)
 not synthesised by the host
 prolonged absence causes a distinct deficiency
 13/14 known vitamins, each has a specific function
 one cannot replace another but some overlap in
function
4

5. Background – Micronutrients: minerals
 elements in their inorganic form
 ~4% body weight
 optimal body function when present within specific range
 continued absence causes a distinct deficiency accompanied
by specific & reproducible biochemical changes, preventable
Classification on basis of requirement by body:
Macrominerals:
◦ needed in amounts > 100 mg/ day eg Ca, P, Mg, Na, K
Microminerals:
◦ needed in amounts < 100 mg/ day eg Fe, Zn, I, Se
Ultratrace elements:
◦ eg boron, cobalt
5

6. Breads and Cereals

7. Breads & Cereals Examples
Breakfast Cereal
Wheat Bread
Maize Ugali
Pasta
Rice
Noodles
Barley
Rice
Sorghum Flour
Semolina
Oats
Polenta
Rye
Couscous
Millet Burghul

9. Which breads and cereals are best?
Wholegrain breads and cereals
provide benefits above refined (e.g.
white)
◦ Less processed
◦ Higher fibre
◦ Lower Glycaemic Index (GI) (will
discuss shortly)

10. Key Nutrients from B&C
 Macronutrients
◦ Carbohydrates
 Micronutrients
◦ Folate
◦ Iron (low bioavailability)
◦ Magnesium
◦ B Group Vitamins (thiamin, niacin)
 Fibre
 Non-nutrients
◦ Anti-oxidants
◦ Phytoestrogens (lignan)

11. Carbohydrate Controversy
 Many popular diets based on low CHO intake
 At odds with most traditional nutrition advice
 Unlimited CHO not appropriate either
 Yes – there is such a things as too much CHO and it
CAN contribute to excess weight gain, especially if in
the form of sugar or high GI carbohydrates
 Thisdoes not then mean that ALL CHO needs to be
minimized

12. Fruit

14. Key nutrients obtained from fruit
Macronutrients
◦ Carbohydrate
Micronutrients
◦ Vitamin C
◦ Folate
◦ Potassium
Fibre
(primarily soluble)
Non-nutrient compounds
◦ Flavonoids
To meet vitamin and nutrient requirements a range of
different types (and colours) of fruits should be eaten!

15. Vegetables
http://www.youtube.com/watch?v=bGYs4KS_djg

17. Key Nutrients from Vegetables
Macronutrients
◦ Carbohydrate (starchy veg & legumes only)
Micronutrients
◦ Vitamin C
◦ Carotene (Vitamin A precursor) (especially orange)
◦ Folate (especially dark green/brassica)
◦ Potassium
◦ Fibre
To meet vitamin & nutrient requirements a range of
types (& colours) of vegetables should be eaten!

18. Variety in the Vegetable Group
• Folate
• Vitamin C • Vitamin C
Green andK
• Vitamin brassica Other
• Potassium
•Carotenoids
• Vitamin A • Carbohydrate
• Carotenoids • Carbohydrates
Starchy
Orange • Iron
Legumes
• Potassium
• Flavonoids

19. Summary of Key Nutrients in B&C, Fruits and
Vegetables
Breads & Cereals Fruit Vegetables Legumes
Macronutrients Macronutrients Macronutrients Macronutrients
• Carbohydrate • Carbohydrate • Carbohydrate •Carbohydrate
•Fibre •Fibre (starchy only) •Protein
•Fibre •Fibre
Micronutrients Micronutrients Micronutrients Micronutrients
• Folate • Vitamin C • Vitamin C •Thiamin
• Iron • Folate •Folate •Niacin
•Niacin • Potassium •Carotene (Vit A) •Iron
•Thiamin • Potassium •Zinc
•Magnesium •Magnesium
Non-nutrient Non-nutrient Non-nutrient compounds Non-nutrient compounds
compounds compounds
•Antioxidants • Flavonoids • Flavonoids •Lignins (phytoestrogen)
•Lignins •Isoflavones
(phytoestrogen) (phytoestrogen) (Soy)

20. Benefits Of Key Nutrients From Breads
& Cereals, Fruits And Vegetables

21. CARBOHYDRATES!!!!!
 Derived from simple sugars (monosaccharides)
◦ Main monosaccharides are glucose, fructose and
galactose
 Main source of energy in diet
◦ Breads & cereals – complex carbohydrates
◦ Fruits & vegetables – simple carbohydrates (mono- &
disaccharides)
◦ Dairy – disaccharides (lactose)
◦ Extras – disaccharides (refined, sucrose)
 Wholegrain B&C, fruit and some starchy veg
provide low GI carbohydrates

22. Glycaemic Index (GI)
 Ranks foods according to rate of
glucose absorption into blood
◦ High GI food absorbed rapidly
◦ Low GI food absorbed slowly
(better control, longer lasting
energy)
 Influenced by:
◦ particle size
◦ degree of processing/cooking
◦ presence of fat, protein
◦ ripeness of some fruit (banana)

23. Glycaemic Index
High (>70)
Glucose, cornflakes, baked potato, white bread,
Weetbix, watermelon, honey, sports drink
Moderate (55-70)
Wholemeal bread, soft drink, brown/white rice,
ice cream, ripe banana, mangoes, orange juice
Low (<55)
Oats, mixed grain bread, All Bran, milk, flavoured
yoghurt, chocolate, unripe banana, pasta, baked
beans, red lentils, apple

24. Benefits of low-GI carbohydrates
Betterblood glucose control
Longer lasting satiety and energy after meals
REMEMBER... Low GI does not necessarily
mean ‘low energy’

25. FIBRE
Dietary
fibre
Soluble Insoluble
• Soluble in water • Insoluble in water
• Forms viscous solutions • Absorbs water while
• Fermented into gasses/ passing through digestive
physiologically active by- system
products in colon • Resists fermentation

26. Health benefits of dietary fibre
Soluble Insoluble
fibre fibre
Form complex Formation of Fermentation bacterial Retention of water
with cholesterol viscous solution proliferation
causing it to in gut slowing
enter colon digestion of
Increase in stool mass – Dilution and
promoting starch &
softer bulkier stools & faster removal of
excretion from absorption of
faster transit through colon carcinogenic
body sugars
compounds
More acidic
Decreased risk Decreased risk Decreased risk colonic
of CVD of diabetes/ of constipation/ environment 
better glycaemic diverticular diminishes
control Decreased risk
disease/ other toxicity of other
of colon cancer
large bowel bacterial
diseases metabolites

27. Fibre Recommendations
Adults
◦ 30g/day used as rough guide
NRV
◦ AI  male adult 30g/day
◦ AI  female adult 25g/day
Children
◦ some say 0.5 g/kg body weight of child
◦ others say age in grams + 5 = minimum
◦ NRV AIs for different age & gender

28. Carbohydrate Recommendations
No AI/ UL as data on essentiality
insufficient
45 – 65% of energy intake to lower
chronic disease

29. Folates
Compounds that exhibit biological
activity of ‘folic acid’
◦ Aid in cell division and protein synthesis (important for DNA
synthesis)
Plant based-foods
Found in:
Animal foods
‘Storage sites’ (liver)
‘Conjugated form’  requires
‘Free-form’ readily absorbed in enzyme for hydrolysis before
small intestine absorption can occur

30. Folate deficiency
Decreased
DNA synthesis Increased
& repair risk cancer
Increased
homocysteine
levels
Impaired
Impaired replacement
cell red blood
division cells
Cardiovascular
disease
Neural
tube Anaemia
defects
(babies)

31. Folate requirements
 Estimated Average Requirement
◦ adults 320 µg/day
 Recommended Dietary Intake
◦ adults 400 µg/day
◦ pregnancy & month preceding conception 600 µg/day
 Suggested Dietary Target
◦ 300-600 µg/day (suggesting need for fortification)
 Upper Limit
◦ adults 1000µg/day

32. Vitamin C
Vitamin C is a water soluble vitamin (can
leach into cooking water so food content
is affected by cooking methods)
Found in

33. Role of Vitamin C
Collagen formation Strong ligaments,
Wound healing &
(primary component tendons, dentin,
tissue repair
of much of the skin, blood vessels
connective tissue) & bones
Vitamin C
Antioxidant functions Aids in the
absorption of non-
haem iron
↓d risk cancer, CVD &
cataracts

34. Vitamin C requirements
 Physiological requirements to prevent scurvy 10-20 mg
 Estimated Average Requirement
◦ adults 30mg
◦ pregnancy 40mg
◦ breastfeeding 60mg
 Recommended
◦ adults
Dietary Intake
45mg
60
◦ pregnancy
◦ breastfeeding
60mg
85mg mg
 Suggested Dietary Target
◦ Men 220mg, Women 190mg
 Upper Limit
◦ not set but 1000mg prudent limit

35. Vitamin
More biologically
active
Retinol Carotenes
 Retinol  supports reproduction (& major transport
storage form of Vitamin A)
 Retinal  vision & conversion of retinol to retinoic acid
 Retinoic acid  modulator of gene expression (controls
mRNA synthesis, cell differentiation growth & embryonic
development)

36. Vitamin A
deficiency
Major nutritional
problem worldwide
◦ Night blindness
◦ Xerophthalmia (failure
to produce tears) leads
to blindness
Rare in Australia as
stored well in liver

37. Vitamin A excess
 Highcarotene intakes from food not toxic but can
cause yellowing of skin
 Chronicintakes of Vit A > 1000 μg/kg body mass
(~100 x RDI) can induce toxicity
◦ Vit. A is fat soluble so it is stored in the body
◦ Symptoms:
 Loss of appetite, headache, blurred vision, irritability, hair loss, general
drying & flaking of skin, bony growths or fractures, liver damage &
death
 In pregnancy, can cause congenital abnormalities

38. Vitamin A requirements
Retinol
 Adequate intake
◦ Infants 250µg/day
◦ Infants 7 – 12 months 430µg/day
 Estimated
Average Requirement
◦ Men 625µg RE Vary according to
◦ Women 500µg RE age for children,
pregnancy and
lactation
 Recommended Dietary Intake
◦ Men 900µg RE
◦ Women 700µg RE
 Upper Limit (adults) 3000µg

39. What about supplements?
 Previously belief existed that it is impossible to obtain
all nutrients from food  multivitamins required for
health
 Beware! Can have excess; low dose multi usually
preferred vs. single large dose
 Consider the cost
 Sometimes are needed (e.g. vegans; very low fat diets;
for allergies; post surgery or illness; malabsorption
problems; pregnancy etc)

40. Other Substances …
There is more to food than nutrients
Many substances may have benefits however
there is much that we do not know
Many important future areas for nutritional
research
Seemsto be more than nutrients/single
components – need more “food” focus due to
unknown elements & interactions likely

41. Phytonutrients
Compounds in food that have the ability
to alter chemical & enzymatic reactions &
therefore the potential to impact on
health which are NOT traditional
micro/macro nutrients
May be beneficial or harmful
Much we still do not know
Nutrients or pharmaceuticals?

42. Possible Roles of Phytonutrients

43. Breads & Cereals Group Long-term Benefits
Consumption of diets rich in wholegrain
breads and cereals may be protective
against
◦Heart Disease
◦Diabetes
◦Some Cancers (e.g. stomach, colon)
◦And is associated with better long-term
weight control
(www.gograins.com.au)

44. Fruit & Vegetables Long-term Benefits
Protective against many major Cancers (stomach & colo-
rectal)
Evidence also exists for protection against
◦ Stroke
◦ High blood pressure
◦ Diabetes
◦ Obesity
◦ Macular degeneration
◦ Dementia
Yet to identify specific protective components - studies of
particular nutrients have found no benefit or harm (Vit-C,
beta-carotene)

45. Summary of benefits of food groups
Breads & Improved
cereals glycaemic
Low GI CHO
control/ ↓d risk
diabetes
Fruits Fibre
↓d risk
Folate gastrointestinal
disorders
Vegetables
Vitamin C ↓d risk CVD
Vitamin A
↓d risk cancer
Improved Strong
↓d risk birth Wound & tissue
eyesight/ muscles,
defects repair
maintenance of tendons etc
eyesight