Nutrients

• Carbonhdrate
• Proteins 
• Lipids (fats and oils)
• Minerals 
• Vitamins 
• Fibres 

• Water

A nutrient is a substance needed by organisms to stay alive and healthy. A healthy human diet involves seven different kinds of nutrient:

Nutrient

Use in the body

Good sources

Carbohydrate

To provide energy

Cereals, bread, pasta, rice and potatoes

Protein

For growth and repair

Fish, meat, eggs, beans, pulses and dairy products

Lipids (fats and oils)

To provide energy. Also to store energy in the body and insulate it against the cold.

Butter, oil and nuts

Minerals

Needed in small amounts to maintain health

Salt, milk (for calcium) and liver (for iron)

Vitamins

Needed in small amounts to maintain health

Fruit, vegetables, dairy foods

Dietary fibre

To provide roughage to help to keep the food moving through the gut

Vegetables, bran

Water

Needed for cells and body fluids

Water, fruit juice, milk

Energy needs

Each person needs a different amount of energy depending on factors such as:

• gender (male or female)
• age
• amount of daily activity

If you look on the side of food packets you will see the food's energy content. This is usually measured in kilojoules, kJ. For example, a one-year-old baby needs 3850 kJ each day to continue to grow, whereas an adult Olympic swimmer in training needs 15,600 kJ each day. Someone who sits at a desk all day will need less food than their twin who climbs ladders all day to wash windows.

Too thin, too fat

If the amount of energy you get from your food is different from the amount of energy you need, your diet will be imbalanced:

• Too little food you eat may cause you to be underweight 
• Too much…