Welcome to practical physicsPracticle physics - practical activities designed for use in the classroom with 11 to 19 year olds
 

Human energy, food and exercise

Class practical

Considering the energy supplied by foodstuffs and the energy demanded by human activity.

Apparatus and materials

Data in the tables below

 

Health & Safety


Procedure


a You should display or provide the data from the following table, Table A:
 
TABLE A: Energy from food
Information given on the packet tells you the energy available from different foods.

Food

Energy value (kcal /100g)

Energy value (kJ /100g)

butter

499

2087

sugar

389

1627

white bread

266

1112

margarine

620

2590

potato, baked

89

372

MacDonald's hash browns

257

1075

hamburger (no cheese)

275

1150

fried fish

221

924

oranges, raw

47

196

lentils, boiled

116

485

carrots, raw

41

171

eggs, fried

201

840

cheese pizza 14"

257

1075

chocolate chip cookies, low fat

453

1895

cola carbonated drink

37

154

corn flakes, breakfast cereal

360

1506

 
Students can be asked to compare the energy available from different foodstuffs.
 
b Display or provide the data from the following two tables, Table B and Table C:
 
TABLE B: Human energy demands

Person

Energy required (kJ/day)

 

Child (either sex)

 

 

0 - 1 yr

4 185

 

2 - 6 yr

6 278

 

7 - 10 yr

8 370

 

Teenager

Males

Females

11 - 14 yr

11 500

11 500

15 - 19 yr

14 650

10 460

Adult (20 yrs and over)

 

 

lying in bed

7 324

6 278

light work

11 500

9 420

heavy work

14 650

12 550

extremely heavy work

20 925

 

 
TABLE C: Data for a coal miner
The miner was 32 years old, 1.75 m tall and had a mass of 67 kg.

Activity

Energy needed (kJ/minute)

resting in bed

3.9

washing, shaving, dressing

13.8

walking

20.5

standing

7.5

cycling

27.6

digging coal

28.0

shovelling coal

26.9

walking (in coal mine)

28.0

A PDF version of these tables is available here.

Teaching notes


1 From Table A, you might ask students to calculate the energy provided by a recent day's food. They will need to know the approximate mass of a normal serving.
 
2 From Table B you might ask students how much energy they need each 24 hours. The answer depends very much on the sort of person, particularly age and occupation. Table C gives some data for a very physical job.
 
The data in these tables could be displayed by a data projector, issued as worksheets, or prepared as wall charts to be left in the classroom or laboratory.
 
This experiment was safety-checked in January 2006