- also referred to as kilocalories, kCal, or kcal; are a measurement of the energy derived from food. 

 - one of the three macronutrients that provide energy in an animal’s diet. They are split into two categories according to their function:

 – Type of carbohydrates found in plants, including cellulose, hemicelluloses and pectins that cannot be produced by the body. While they are of no direct nutritional value (they are not digested or absorbed), dietary fibres are very important: insoluble fibres do not absorb water. They provide bulk, which facilitates intestinal transit and helps t [..]

 – The degree to which a food item can be broken down into its components for use in the body.

 - In order to function properly, an animal’s body needs the energy contained in its food (whether animal or vegetable in origin). Energy is measured in Calories and is provided by carbohydrates, proteins, and fat.

 - The amount of energy required to fulfill the body’s daily energy needs. This amount depends on age, physiological status (growth, gestation, lactation, maintenance, illness etc.), physical activity, size of animal (in dogs) and neuter status (in dogs and cats).

 – type of proteins that help to break down materials (such as food) in the body, without being altered themselves.

 – a nutrient that needs to be obtained from the diet. Essential nutrients either cannot be made in the body or cannot be made in sufficient quantities to meet the needs of the body.

 - one of the three macronutrients of an animal’s diet. They provide an energy rich fuel source and supplying building blocks for the formation of tissues in the body.

 – A series of muscular organs where food is digested and made available for absorption. These organs include the mouth, esophagus, stomach, and small and large intestines.