### BMI calculator

```Healthy Living: problems for
the classroom
• BMI calculator (using formulae)
• Eat well, move more, live longer (real life
calculations)
BMI Calculator
• Body Mass Index (BMI) is one of the measures that doctors
and others use to help determine how healthy a person is.
• It simply uses the person’s height and mass .
• Although the calculation is the same for adults and children,
the interpretation is different.
• For normal adults the healthy range for BMI is considered to
be 19 to 25. This changes if the person is particularly fit and
muscular.
• It is calculated using the formula:
where mass is in kg and height is in m.
=

ℎ 2
Using the BMI calculator
Using the formula  =

ℎ 2
What is the BMI for each of the following people:
• A man of height 1.84 m and mass 86kg?
• A woman of height 165cm and mass 62kg?
• A man of height 192cm and mass 68kg?
What is the healthy range of masses for a woman of height 165cm?
If a normal healthy man has a mass of 80kg, what height might he
be?
Many people still work with imperial measures; what would be the
BMI of a person height 5 foot 7 inches, weight 10 stone 3 pounds?
Eat well, move more, live longer
The NHS has a campaign called change4life to encourage
… but how much more should a person move to balance
excess calorie intake?
A 100g bar of chocolate is approximately 500 kcals and a
35g bag of crisps is approximately 200 kcals.
How much exercise might a person need to do to balance
each of these?
Eat well, move more, live longer
The table on the next slide gives the amount of calories
burned for various forms of exercise.
Calories burned when exercising are also dependent on
body mass; figures given are for a 70kg person, exercising
for an hour.
• If a person ‘over-ate’ 1400 calories a week (equivalent to
2 chocolate bars and 2 bags of crisps) what exercise
might they do during the week to burn off exactly the
1400 calories?
• Devise a varied exercise plan for the week.
• You might like to think about putting together an
inexpensive plan that anyone could follow.
Eat well, move more, live longer
Exercise
Calories
Exercise
Calories
Aerobics
457
Hockey (field)
563
317
Horse riding
281
422
Housework
246
Bowling
210
Martial arts
704
Cycling (slow)
281
Mowing a lawn
387
Cycling (fast)
704
844
Fishing
176
Running (5mph)
563
Football
493
Skateboarding
352
Golf
317
Swimming
493
Gymnastics
281
Walking (brisk)
267
Teacher Notes
BMI calculator
• It is important to stress that BMI is just one indicator for assessing health
and fitness – and that the 19 to 25 range does not apply to children
1.84 m and mass 86kg: 25.4
165cm and mass 62kg: 22.8
192cm and mass 68kg: 18.4
Range of masses for a woman of height 165cm: 51.7kg to 68.1kg
Mass of 80kg, what height might he be: 1.78m to 2.05m
BMI if they are 5 foot 7 height and weigh 10 stone 3 pounds: equivalent to
1.70m and 65 kg so BMI is 22.5
Teacher Notes
Eat well, move more, live longer
It should be stressed that we all need a certain amount of calories, but that
healthy living is about balancing what a person eats with how much exercise
they do.
This activity is designed for students to devise their own exercise plan, so there
are no definitive answers, but the extra table given in these notes can be used
as a quick reference guide.
On slide 5, students might make guesses about how much exercise is required
to burn off a chocolate bar or bag of crisps, this can then be ‘checked’ with the
information on later slides.
To find exercises to burn of exactly 1400 calories, students will need to
calculate to the nearest minute.
You might like to add restrictions such as ‘There must be 4 different activities
and the total exercise time should be between 3 and 4 hours”
Teacher Notes
The table below shows how many minutes it takes to burn
100 calories for each of the forms of exercise.
Exercise
Time
Exercise
Time
Aerobics
13
Hockey (field)
11
19
Horse riding
21
14
Housework
24
Bowling
29
Martial arts
8.5
Cycling (slow)
21
Mowing a lawn
15.5
Cycling (fast)
8.5
7
Fishing
34
Running (5mph)
11
Football
12
Skateboarding
17
Golf
19
Swimming
12
Gymnastics
21
Walking (brisk)
22
Sources
• BMI calculator
• Reference graphs for children’s BMI
• Calories in various foods
• List of calories burned by exercise
```