Energy

Your body derives energy from food to allow you to perform various tasks and processes. The energy we acquire from food, and the energy we expend is measured by the following:

Calories (cals)

The energy yielded from carbohydrate, fat and protein can be measured in small units of energy called calories. There are literally thousands of calories in food, so to make calculations easier, energy is expressed in 1000-calorie units known as kilocalories (kcals/kcalories). However kilocalories are most commonly called calories. So as not to confuse any users, all the content in this website will always refer to kilocalories as calories.

Calories are a heat measurement:

• 1 x calorie increases the temperature of 1gram of water by 1 degree Celsius
• 1 x kilocalorie increases the temperature of 1kilogram of water by 1 degree Celsius

Kilojoules (KJ)

The energy yielded from carbohydrates, fat and protein can also be measured in small units of energy called kilojoules (kilojoules = 1000 joules).

Kilojoules are a measurement of work energy:

• 1 x joule is the amount of energy expended when 1kilogram of weight is moved 1metre by a force of 1 Newton

Macronutrients

Carbohydrate, fat and protein are the macronutrients (nutrients required in large amounts) that provide your body with energy.

Carbohydrate

Carbohydrate is your body’s preferred source of fuel and provides 4 calories of energy per gram (or 16.7 kilojoules per gram). Carbohydrate provides you with both quick and sustained energy. 

Common sources of carbohydrates are:

• Lollies
• Pasta
• Rice
• Fruit
• Sugar
• Soft-drink
• Cereal
• Bread

Fat

Fat provides you with cushioning, insulation and energy. It is also involved in brain function, nerve transmission and hormone production. Fat yields 9 calories of energy per gram (or 37.7 kilojoules per gram).

Common sources of fat are:

• Butter

• Dairy foods

• Pastries

• Cakes

• Chocolates

• Oils

• Avocado

Protein

Protein is what your body uses to build and repair tissue such as muscle, hair, nails and skin.  It is also involved in the making of enzymes, antibodies and hormones. Protein provides 4 calories of energy per gram (or 16.7 kilojoules per gram).

Common sources of protein are:

• Beef
• Pork
• Lamb
• Wild game meat
  
• Dairy foods
• Poultry
• Fish
• Nuts

NOTE:

1 calorie = 4.184 kilojoules
1 kilojoule = 0.239 calories