What is a Calorie?

Calories, Kilocalories (Kcal), and Kilojoules (kJ) are heat units for measuring food energy. Heat and energy mainly come from 3 nutrients: carbohydrates, protein and fat.

Energy Unit Exchange Rate
1 Kcal = 4.18 kJ

 

Energy Nutrients Table

Energy-providing nutrients
Heat energy (kcal/g)
Fat
9
Protein
4
Carbohydrates
4
 
Approximate energy nutrient content of one serving of six different food types:

1 serving of food group
Carbohydrates (g)
Protein (g)
Fat (g)
Meat/Fish/Egg/Legumes

--

14

8
Grain/Starch

35

3

--
Milk - Whole or full cream
 12 8 8
Milk - "Low fat"

12

8

4
Milk - Nonfat

12

8

--
Vegetables
15

1

--
Fruit

10

--

-
Fat (oil)

--

--

5