Although I set out below, in a spreadsheet, the answer to the question,” how many calories does a cat need?”, there are stages in the life of a cat when it has increased or decreased energy requirements and a list of these variations are also set out in the spreadsheet below (2nd block down). There are also the natural differences in cat size and weight to contend with. Illness can also increase energy requirements .
Calories are required to supply a cat’s daily energy needs for these purposes:
- maintain resting metabolic rate (RMR) – this is the energy needed to maintain homeostasis during rest. Homeostasis is the regulation of a stable condition inside the body3 including such functions as blood circulation, respiration, kidney and liver function2. Cats with a high proportion of lean tissue (e.g. young cats) will have a high RMR.
- meal-induced thermogenesis (thermogenesis is the process of heat production in organisms. It occurs mostly in warm-blooded animals1) . When cats eat energy is consumed to digest, absorb and utilise the nutrients2. About 10% of the calories in the food eaten is “lost” in this way.
- voluntary muscular activity. This is responsible for about 25-30% of overall energy consumption.
- maintenance of body temperature2
The charts below, in respect of the calorie needs of a cat, are to be used as a starting point only.
The energy in food comes from three major sources:
- Carbohydrates (28% of energy source in cat food for adult maintenance)
- Proteins (28%)
- Fats (44%2)
The carbohydrates in cat food comes from cereal, legumes (the fruits or seeds of anything that comes in a pod5) and plant foodstuffs4.
A rough test for a normal sized cat is to take a commonsense view. Is your cat well proportioned? Can you feel the ribs (thin covering of fat over the ribs)? The waistline should be moderate. See cat obesity.
How many calories does a cat need? — Sources:
- 1. http://en.wikipedia.org/wiki/Thermogenesis
- 2. The Cat, Its Behaviour, Nutrition & Health
- 3. .
- 4. http://dels.nas.edu/dels/rpt_briefs/cat_nutrition_final.pdf.
- 5. http://www.awsc07100.pwp.blueyonder.co.uk/BBGuidelines/BBG-LEGUMES.htm