# Energy for Life

In this worksheet, students will explore how the energy needs of people differ and how the energy contained within foods is measured.

Key stage:  KS 3

Curriculum topic:   Biology: Structure and Function of Living Organisms

Curriculum subtopic:   Nutrition and Digestion

Difficulty level:

### QUESTION 1 of 10

Your body changes the chemical energy contained within the food you eat into the energy you need to stay alive.

Different foods contain different amounts of energy. For example, a typical meal of a hamburger, chips and a fizzy drink contains about 4000 kJ of energy.

The hamburger contains approximately 2000 kJ, the chips contain 1300 kJ and the fizzy drink contains about 700 kJ of energy.

This may seem like a lot of energy, but different people have different energy needs depending on their age and lifestyle. Shown below are the approximate energy needs of a wide range of people.

Person Energy need per day (kJ)
2 year old  4000
10 year old 8000
14 year old girl 10000
14 year old boy 12000
Adult male with an active job 14000

The energy needs depend on age and lifestyle. An active person requires more energy than a person who works at a computer most of the day.

It is important to provide your body with the correct amount of energy.

If a person takes in a lot of energy but does not lead an active lifestyle then they may become overweight, but a person who does not take in enough energy may become underweight, both of which can cause health issues.

It is also important to have a balanced diet, containing the correct amounts of vitamins and minerals.

Which of the following are the correct units for energy?

seconds

kiloJoules

decibels

Which of the following people do you think requires the greatest amount of energy per day?

A 35 year old male builder

B 25 year old female office worker

C 14 year old school boy

A

B

C

Match up the correct energy values on the left with the people on the right.

## Column B

4000 kJ
14 year old girl
14000 kJ
2 year old
10000 kJ
14 year old boy
12000 kJ

Shown here is a list of foods. Decide whether the foods listed would have a high or low energy content.

 High Low Burger Fish and chips Salad with no dressing Chocolate cake Fruit Baked beans

Shown below is the label from a common food:

Use the table to help you work out how much energy is contained in a 300g portion.

1007 kJ

2014 kJ

3021 kJ

What can happen if you consume more energy than your body requires?

you may become underweight

you may become overweight

you will become stronger

Which of the following are part of a healthy diet?

Tick the answers you agree with.

vitamins

alcohol

minerals

a variety of foods

vitamins

alcohol

minerals

a variety of foods

Jade is going to be playing football this afternoon.  Which of the following breakfasts do you think would be best for her in terms of both energy input and general health?

Tick any you agree with.

cereal, milk, fruit juice

fried bacon, sausage, eggs, has browns

scrambled egg, toast, banana, cup of tea

pancake with syrup, bagel with honey, chocolate milk

Once Jade has finished her football match, she is very hot and sweaty.

Complete the following sentence:

cereal, milk, fruit juice

fried bacon, sausage, eggs, has browns

scrambled egg, toast, banana, cup of tea

pancake with syrup, bagel with honey, chocolate milk

• Question 1

Which of the following are the correct units for energy?

kiloJoules
EDDIE SAYS
Energy is measured in Joules (J). Named after James Joule who was the first scientist to realise that there are many different forms of energy. So, 1000J of energy is 1KJ, following the metric system of SI units.
• Question 2

Which of the following people do you think requires the greatest amount of energy per day?

A 35 year old male builder

B 25 year old female office worker

C 14 year old school boy

A
EDDIE SAYS
Adults with active jobs require lots of energy to remain healthy. So, the builder expends a great deal of energy during the day and so will need a bigger store of chemical (food) energy to draw from than the other two in order to complete his daily tasks.
• Question 3

Match up the correct energy values on the left with the people on the right.

## Column B

4000 kJ
2 year old
14000 kJ
10000 kJ
14 year old girl
12000 kJ
14 year old boy
EDDIE SAYS
Different people have different energy needs. The table in the introduction lists some of the approximate energy needs of a wide range of people. If you studied that, you'll have had some idea of people's needs and so realise that an active job requires more energy and that teenage boys need more energy than teenage girls.
• Question 4

Shown here is a list of foods. Decide whether the foods listed would have a high or low energy content.

 High Low Burger Fish and chips Salad with no dressing Chocolate cake Fruit Baked beans
EDDIE SAYS
Fatty foods such as burgers and fish and chips are very high in energy. So called 'healthy foods' such as salad and fruit are lower in energy.
It is important for your own health to be aware of your energy needs and what amount of energy you are consuming.
• Question 5

Shown below is the label from a common food:

Use the table to help you work out how much energy is contained in a 300g portion.

3021 kJ
EDDIE SAYS
Food packaging must contain information of the chemical energy contained within the food, as well as providing information on salt content etc...
Here, we can see that 100g contains 1007 kJ of energy. This means that 300g would contain 3021 kJ, as 1007 x 3 = 3021.
• Question 6

What can happen if you consume more energy than your body requires?

you may become overweight
EDDIE SAYS
It is important to lead a healthy lifestyle and make sure that, if you are going to consume lots of energy, you do the right amount of exercise to balance it out. Unfortunately, in today's world, the easy availability of cheap, sugary foods together with a lack of exercise mean that an awful lot of young people are becoming overweight as they are unable to work off all the energy they take in.
• Question 7

Which of the following are part of a healthy diet?

Tick the answers you agree with.

vitamins
minerals
a variety of foods
EDDIE SAYS
A healthy diet should be balanced, which means it has a variety of foods that meet the your energy needs. Vitamins and minerals contain no energy but provide vital nutrients that ensure your body functions correctly.
• Question 8

EDDIE SAYS
Si, it's a meal that many people either skip or just snack through, but in truth breakfast is really important to your body and to your ability to set yourself up for the day. Not only does it give you that initial energy 'kickstart' to your day, but it helps you concentrate through the morning.
• Question 9

Jade is going to be playing football this afternoon.  Which of the following breakfasts do you think would be best for her in terms of both energy input and general health?

Tick any you agree with.

cereal, milk, fruit juice
scrambled egg, toast, banana, cup of tea
EDDIE SAYS
OK, so they're all going to give energy, but some give too much and they're wrapped up in too much fat and sugar. Jade's body needs easily-accessible energy (carbohydrates), without too much tooth-rotting sugar and not too much fat, which is harder to extract the energy from.
• Question 10

Once Jade has finished her football match, she is very hot and sweaty.

Complete the following sentence:

EDDIE SAYS
As she has lost so much water in playing her match, the best thing for her to drink is the same thing her body has lost: water! Her digestive system doesn't have to do anything with it apart from absorb it into her body and use it replenish the diminished water reserves.
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