1. Diet & Nutrition

2. Functions of Food
ENERGY
GROWTH
PROTECTION

3. Tim & Moby Why we Eat

4. A balanced diet requires the correct food groups in the correct amounts. These include:
Carbohydrates
Fats
Proteins
Vitamins
Minerals
Fibre
Water

5. simple carbohydrates: sugars
carbohydrates, C, H, O
simple carbohydrates: sugars
e.g.
Glucose in
Lactose in milk
Use: energy release

6. complex carbohydrates: cellulose, in plant cell walls e.g. fruit
Use: Provides support
glycogen, found in animal liver & muscle cells
starch, found in plant cells e.g. bread, pasta, rice
Use: energy storage

7. made from fatty acids and glycerol animal fats are solid e.g. butter
fats C, H, O
made from fatty acids and glycerol
animal fats are solid e.g. butter
plant fats are liquids e.g. olive oil
Use: insulation, protection, energy storage

8. Animal protein e.g. eggs, meat, fish
proteins C, H, O, N
made from amino acids
Animal protein e.g. eggs, meat, fish
Plant protein e.g. nuts, pulses, Quorn
Use: growth and repair

9. vitamins
Needed in only very small amounts and are important in maintaining our general health

10. vitamin C Found in fresh vegetables and citrus fruit
It is needed to maintain blood vessels,
and for development of teeth and gums
A deficiency of vitamin C leads to scurvy (sore gums and bleeding around bones and from the intestine)

13. vitamin D Found in fish liver oil, liver, milk, eggs
The skin can also make vitamin D when exposed to sunlight
It is needed to regulate the use of calcium and phosphorus for making bones and teeth
A deficiency of vitamin D leads to rickets (soft bones that bend and dental decay)

15. Also needed in very small amounts
minerals
Also needed in very small amounts

16. calcium Found in dairy products
It is needed for making bones and teeth
A deficiency leads to poor
development of
bones and teeth

17. iron
Found in red meat
It is needed for making haemoglobin in red blood cells
A deficiency of iron causes anaemia; anaemic people are very tired. This is because haemoglobin allows RBCs to carry oxygen which is needed for respiration to release energy.

18. FIBRE WATER Read page 32 and make notes on For both you need to write
What it is used for
Where we get it
What happens if it is deficient
FIBRE
WATER

19. homework revision

20. Tim & Moby Healthy Eating

21. Starvation
Starvation occurs when a person does not get enough food to eat.
The body is using more energy than the diet is supplying.

22. Malnutrition The correct quantity
of food is eaten, but it may consist of only one food type, or a poor balance.
Kwashiorkor
results from a diet lacking
enough protein.
It results in swollen stomach
and is common in countries
where the diet consists mainly rice or maize

23. No change from yellow/brown
Negative:
No change from yellow/brown
Positive:
Blue/black

24. Green, yellow/orange, brick red
Negative:
No change from blue
Positive:
Green, yellow/orange, brick red

26. Negative:
No change from clear
Positive:
Cloudy suspension

27. Food Tests
Worksheet
Cluedo activity

28. testing for
vitamin C

29. vitamin C
turns
blue DCPIP
clear

30. The fewer drops of juice added , the more vitamin C is present in the liquid.

31. DO THIS AS A DEMMO AND THEN DISCUSS HOW TO MAKE THE EXPT MORE ACCURATE: USE OF GRADUATED SYRINGE

32. DO THIS AS A DEMMO AND THEN DISCUSS HOW TO MAKE THE EXPT MORE ACCURATE: USE OF GRADUATED SYRINGE

33. investigating
vitamin C content

34. The variable changed was the treatment of the Fruit Juice
fair test
only one variable changed
all others remain the same
The variable changed was the
treatment of the Fruit Juice
The same volume of DCPIP was
used in each experiment
The same type of juice was used

35. when repeated reliable data
reliability
when repeated reliable data
will be of similar size
Discuss the reliability of the class
results
Results that are far away from the others are called anomalous results
Do you have any anomalies?

36. accurate results will be
accuracy
accurate results will be
measured precisely
It would have been more accurate to use a measuring cylinder to measure the 1cm3 DCPIP.
The syringe did not measure exactly 1cm3, so some experiments had more or less DCPIP.

37. results are not valid if something cannot be controlled
validity
results are not valid if
something cannot be controlled
and it affects the results
It was not possible to control the size of the drops of fruit juice using a dropper.
It would have been more valid to use a burette and measure the volume of fruit juice needed to change the DCPIP from blue to clear.

38. Use the trial controlled assess material?

39. Comparing the energy content of different foods (WS)
BT in clamp
Thermometer
Mounted needle
Boiling tube
25cm3 water
food

40. in science ENERGY IS MEASURED IN
joules (j)
kilojoules (kj)
megajoules (mj)
most food packets also measure energy in calories

41. how much energy do we need?
Energy needed per day by different people in different situations

42. factors affecting
energy
requirements

43. 3 main factors affect our
energy requirements, and therefore how much and what we need to eat
age
a baby needs less energy
than a teenager

44. generally men have more muscle than women
gender
generally men have more muscle than women
which uses more energy

45. a physically demanding activity
requires more energy than a restful one

46. the extra energy is obtained
from meals containing
lots of carbohydrates
These are broken down
to release the energy
in respiration

47. due to the high rate of growth of the developing foetus
pregnant women
have high energy needs
due to the high rate of growth
of the developing foetus

48. Pregnant women need extra nutrients for the developing baby:
calcium for the growth of bones
iron for the production of red blood cells
Nursing or breastfeeding mothers need extra
Protein & fluid to make milk

50. bmi
The body mass index is a measure of whether someone is the correct weight for their height.

51. Weight is measured in kg Height is measured in metres
calculating BMI
BMI = weight
height 2
Weight is measured in kg
Height is measured in metres

52. Using BMI values BMI value Description Under 18.5 Underweight
18.5 – 24.9
Normal
25 – 29.9
Overweight
30+
Obese

53. This graph allows you to compare the BMI of a range of boys of the same age.
Percentiles are used to indicate the range of values associated with being
underweight, less
than 5%
ok, 5-85%
overweight, 85-95%
and obese, over 95%.

54. Percentage increase in BMI can be calculated by finding the difference between the initial and final BMI. Divide this by the initial BMI and multiply by 100.
Percentage change in BMI = CHANGE IN BMI X 100
initial BMI
e.g.
A 10 year old boy on the 85th percentile has a BMI of 19.5
At 20 years old on the 85th percentile he has a BMI of 27.0
Change in BMI = 27.0 – 19.5 = 7.5
% change in BMI = X 100 = 38.5%
19.5

55. having a higher energy intake
obesity is caused by
having a higher energy intake
than the energy used

56. The basal metabolic rate is a measure of the minimum energy use.
bmR
The basal metabolic rate is a measure of the minimum energy use.
It is found when a person is inactive, resting in a reclining position
The person must not be stressed due to hunger, but must have digested their last meal.

57. To calculate your BMR you need to know:
calculating BMR
BMR calculator
To calculate your BMR you need to know:
Height
Weight
Age
gender

58. Using BMr values Use the HARRIS BENEDICT EQUATION
to calculate how much energy you need,
in calories
From the table decide the activity factor.
Multiply the BMR by the activity factor.
This gives the number of calories you
need to eat to stay at your current weight.

59. A 15 year old girls is 1.6m tall and 57Kg.
Her BMR (from calculator) is
She is quite active, playing netball and hockey for the school teams, so she practises every day.
Her activity factor is (very active).
To find the energy she needs multiply BMR by activity factor.
x = 2229 Calories = Kj

60. because we become less active
Activity factor
Category
1.2
Minimal exercise
1.375
Lightly active
1.55
Moderately active
1.725
Very active
1.9
Extremely active
BMR decreases with age
because we become less active
and need less energy

61. diets rich in sugar, salt and fat or low in fruit and vegetables
health & diet
diets rich in sugar, salt and fat
or low in fruit and vegetables
contribute to health problems

62. obesity

63. eating too much energy:
sugar, starch, fat

64. the heart must pump harder to pump blood round the extra tissue
in obese people
the extra wear and tear may
damage the heart or blood vessels

65. heart
disease

66. high levels of cholesterol & other fatty substances
build up in artery walls
over time arteries narrow,
less blood flows through them,
& may cause a heart attack

67. strokes

68. in arteries in the brain blocks the flow of blood
build up of fat
in arteries in the brain
blocks the flow of blood

69. high
blood pressure

70. too much salt
in the diet

72. too much sugar in the body
prevents insulin from
controlling
blood sugar levels

73. arthritis

74. extra wear and tear on joints
extra weight causes
extra wear and tear on joints
e.g knees, hips,
lower back

75. The factors which affect health and cause these diseases can be divided into 3 groups:
Dietary e.g eating too much saturated fat, sugar or salt and eating too little fruit and vegetables
Environmental e.g. stress
Hereditary the genes you inherit from your parents can make you more susceptible to certain diseases such as heart disease

76. It is possible to control diet and environmental factors, and so reduce the chance of getting these diseases.
Whilst it is not possible to control the genes you inherit, by controlling the effects of diet and environmental factors you are reducing the chance of getting these diseases to a minimum.

77. costs to society
The number of people with obesity has doubled over the past 20 years to 20% of the population.
The NHS is paying more to treat people for obesity and for the medical conditions associated with obesity such as type 2 diabetes and heart disease.

78. Read the following articles
Obesity Tsunami
Talking scales to combat obesity
In pairs produce a slogan, no longer than 10 words, which could be used in the campaign to fight against obesity.