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.

Using the BMI calculatorUsing the formula answer the following:

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 longerThe NHS has a campaign called change4life to encourage

people to adopt healthier lifestyles…

… 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?

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

Eat well, move more, live longerExercise Calories Exercise Calories

Aerobics 457 Hockey (field) 563

Badminton 317 Horse riding 281

Basketball 422 Housework 246

Bowling 210 Martial arts 704

Cycling (slow) 281 Mowing a lawn 387

Cycling (fast) 704 Roller blading 844

Fishing 176 Running (5mph) 563

Football 493 Skateboarding 352

Golf 317 Swimming 493

Gymnastics 281 Walking (brisk) 267

Teacher NotesBMI 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

Answers:

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 NotesEat 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”

The table below shows how many minutes it takes to burn 100 calories for each of the forms of exercise.

Teacher Notes

Exercise Time Exercise Time

Aerobics 13 Hockey (field) 11

Badminton 19 Horse riding 21

Basketball 14 Housework 24

Bowling 29 Martial arts 8.5

Cycling (slow) 21 Mowing a lawn 15.5

Cycling (fast) 8.5 Roller blading 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