1. Learning
Objectives
• To introduce the 5 nutrients
• To explain the functions and sources of nutrients
• To understand what happens if there is a nutrient deficiency
2. Why do we eat food?
Apart from enjoyment and social
activity, we eat food because our
bodies need:
• energy;
• compounds for growth, repair and
reproduction;
• substances to regulate the
production of energy, growth and
repair.
3. What are nutrients?
Food contains a mixture of different nutrients which have different functions in the body.
They are the chemicals found in food.
There are 5 main nutrients:
1. Protein – HBV, LBV
2. Carbohydrates – Starch & Sugar
3. Fats
4. Vitamins – such as A,B group, C, D, E
5. Minerals – such as Iron & Calcium
Water and fibre are also very important to include in the diet, but they are not classed as
nutrients in this course.
• Food is eaten and digested in the body to allow the absorption of energy and nutrients.
• Each nutrient will have a different role / function in the diet
• Each food contains different nutrients and in different amounts.
• Different people need different quantities of each nutrient
4. The energy supply
Foods containing…
• protein
• carbohydrate
• fat
…provide the body with energy.
These are also known as ‘Macronutrients’
5. 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
6. 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).
7. 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.
8. Now let’s look a little closer at what else the nutrients do
For this course, we only need to cover basic nutrition.
You need to know and understand:
Types of nutrients there are
The functions of nutrients in the body
The good sources of nutrients – i.e. what foods they are in
Deficiency / Excess nutrients - the effects
Nutritional requirements of different people
What is a Healthy Balanced Diet
9. Protein
What is the function of protein?
Protein is needed by the body for growth, development and repair of body cells. It is
Sometimes known as the ‘body builder’
Protein is really important as it is the only nutrient that can do this.
Protein can also provide energy, but not as much as fat or carbohydrate.
What consumers would need more protein? Why?
Good sources of protein?
There is protein in any natural product that has ‘grown’, but some foods are a
better source than others:
Animals – fish, meat, cheese, milk, eggs
Plants – peas, beans, lentils,(sometimes called pulses) nuts and cereals
HBV & LBV
These are the 2 types of protein.
HBV – High Biological Value
LBV – Low Biological Value
So what’s the difference?
10. Proteins are made up of amino acids. There are around 20 different types. There are
8 essential amino acids needed for adults and 10 for children.
HBV proteins will have all essential LBV proteins will have some of the
amino acids required essential amino acids required, therefore
it is important to eat a variety of LBV
protein sources
Complimentary Proteins are a mixture of LBV proteins that
together will provide all the essential amino acids. E.g. rice and
peas
11. Fat
What is the function of fat?
Fat provides the body with essential fatty acids and energy.
One gram of fat provides 37 kJ (9 calories), which is more than any other
nutrient.
Fat provides a store of energy for the body.
Fat also provides protection for the major organs in the body.
Fat carries important fat soluble vitamins (A, D, E and K) and is important for
their absorption.
Types of Fat
. • saturated;
• unsaturated;
- monounsaturated;
- polyunsaturated.
Fat is needed for health, but only in moderate amounts. Too much fat can eventually
lead to obesity, coronary heart disease and other health issues
Saturated fat is the type that we should eat the least of.
In cooking we use 2 main types – fats, which are solid at room temperature and oils
which are liquid.
What are sources of fat?
Butter, margarine, lard, sunflower oil, sesame oil, cheese,
12. Where is fat found?
Saturated fat can be found in meat, coconut oil, palm
oil, cakes, biscuits, and lard.
Unsaturated - Monounsaturated and polyunsaturated fat can be
found in rapeseed oil, olive oil, oily fish, avocado and some
margarines and low fat spreads.
13. Carbohydrate
What is the function of Carbohydrates?
They provides an important source of energy for the body.
Carbohydrate provides 16kJ per gram. (half as much as Fat does)
Types of Carbohydrates
The two main types of carbohydrate are:
1) sugars;
2) starch.
Whole grains are known as ‘complex’ carbohydrates
Sugars are known as ‘simple’ carbohydrates, often being called ‘empty calories’
Good Sources of Carbohydrates
Foods that fill you up are generally starchy carbohydrates e.g. bread, rice, pasta, Potato
Foods that are sweet are sugar carbohydrate e.g sugar, honey , jam, fruit,
14. Where is carbohydrate found?
Some examples of sugar sources (carbohydrate) are sucrose
(found in table sugar), lactose (found in milk), and fructose (found
in fruit).
Some examples of food sources for starchy carbohydrates are
bread, pasta, and cereal.
15. We will look at Micronutrients (Vitamins and
Minerals), Water and Fibre in another lesson
