# 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

#### 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

#### 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