© British Nutrition Foundation 2004 The Basics of Nutrition.

© British Nutrition Foundation 2004

The Basics of Nutrition


Why do we eat food?We eat food because our bodies need:

• energy;

• compounds for growth, repair and reproduction;

• substances to regulate the production of energy, growth and repair.


What do our diets contain?• A balanced diet contains a wide variety of foods

• Food contains a mixture of different nutrients which have different functions in the body.

• A healthy diet will provide adequate amounts of all nutrients needed by the body for good health.


The energy supply

Foods containing…

• protein

• carbohydrate

• fat

…provide the body with energy.


The other functions

Food also provides…

• fibre;

• water;

• vitamins and minerals.

These substances do not provide the body with energy, but are all needed to fulfil some important ‘support’ functions for the body.


How is energy measured?

Energy is measured in units known as kilojoules (kJ).

Energy is also measured in calories (kcal). This is a different way of measuring energy, just as distance is measured in centimetres and inches.

1 calorie = 4.2 kJ


Energy and nutrients

Food and drinks provide us with different amounts of energy because of the variety of nutrients they contain.

1g protein provides 17kJ (4 kcal).

1g carbohydrate provides 16kJ (3.75 kcal).

1g fat provides 37kJ (9 kcal).



How is the energy released from food?

• In order to release the energy contained in food, it needs to be broken down.

• The breakdown of food to release energy is called ‘digestion’.

• Digestion is the breakdown of food molecules into small units that can be absorbed.

• Digestion starts in the mouth with chewing, it then continues to the stomach, small intestines and large intestines.


Energy balance

• Different people need different amounts of energy.

• It is important to balance the amount of energy we eat with the amount of energy we use up.

• Keeping our bodies active helps to keep us healthy.

• Some activities use more energy than others.


Energy balance

• Too much energy from food and drink is stored as fat in the body.

• Eat the right amount to be a healthy weight.

• As we get older the amount of food we need changes.


Energy in vs Energy out

These foods provide 400kJ of energy:


Energy in vs Energy out

Number of minutes to use up 400kJ of energy:


Enjoy your foodand keep active!

© British Nutrition Foundation 2004 The Basics of Nutrition.

Documents

kj energy

kj of energy

production of energy

energy compounds

energy supplyfoods

different amounts of

vs energy outthese foods

different functions