Recent studies of cats in the United States suggest that 30 to 40 per cent of them are overweight or obese. This alarming statistic may be due in part to the significant difference between the diets of even the most healthy domestic cats and those of their feral cousins and wild ancestors.
Many owners, even with the best intentions, may be feeding cats in a way that contributes to weight gain. And the way in which kittens are exposed to different foods may also influence their dietary preferences and eating habits in later life, often in a way that predisposes to obesity.
The majority of cat owners feed either straight dry food, or a combination of both dry and moist food. A smaller minority use only canned food. There is great variability between one type or brand of dry cat food and another, but it is estimated that a bowl of dry cat food contains 200 or more calories. And unfortunately, cat food bowls are often kept full for ad lib eating throughout the day. (See this for a discussion of free choice feeding.) By contrast, the average mouse or bird in a wild diet contains about 35 calories, and it is estimated that about 8 of these must be eaten daily to stay healthy. That equates to approximately 250 calories per average sized housecat per day.
A full bowl of dry food, replenished two or three times a day, represents a high-calorie high-carbohydrate diet, and although this is a convenient way of feeding for many human owners, it may also be a recipe for feline obesity, particularly in less-active indoor cats who do not burn calories in self-defense and hunting.
Another contributor to cat weight gain is spaying or neutering. Removal of the hormone-producing testicles and ovaries may improve cats’ health in many ways and certainly helps to deal with a potentially exploding animal population, but it reduces your pet’s metabolic rate and allows food to affect weight more directly, as in men and women after andropause and menopause.
It is estimated that food intake should be reduced by 20 to 30 per cent after neutering in order to prevent weight gain. For cats older than 1 year, a heaping bowl of dry food is not a good idea; the amount that you feed your cat should always be measured out and fed twice a day. Another useful approach is to put the allotment in a plastic food ball, so that the cat expends some calories in getting the food by rolling the ball around to get the food out. This kind of activity may also reduce any tendency to eat out of boredom, especially when the humans are not around.
What cats like to eat is importantly affected by what they are exposed to as kittens. Kittens do not differ much in nutritional requirements from adult cats, and cats are less likely to be picky eaters if they are exposed to different types of food as kittens, although some studies have suggested that the food preferences of kittens are influenced by what their mothers ate when carrying them.
Kittens and cats in general should eat diets that are high in protein, moderate in fat and low in carbohydrate; the main difference between kittens and adult cats is that kittens need more calories per pound, and for that reason do better with kitten foods that are higher in protein and fat. Cats need fatty acids for heart, skin and joint health and to prevent the development of inflammation. Foods that list a high concentration of these are preferable, and fish oils that are high in fatty acids are among the most useful dietary supplements for cats and kittens.