What is a Calorie?

Everything we eat contains calories. We need them to function and carry out everyday tasks. How do we know which foods are right to eat and which contain 'empty calories'? Chemistry - Chemical Industries - Learning Points. Calories are in everything we eat and we need them to survive. A calorie is a unit of energy, and one thousand calories are equal to a kilocalorie. Energy content is also measured in joules and kilojoules. A healthy diet needs to balance the calorific and nutritional value of food. A Twig Context Film. Reinforce and extend the learning required by the curriculum. Twig’s context films show abstract concepts in action in the real world.