Keeping slim and lean is a major problem for the indoor cat. Typically, a neutered cat living in a stable, warm but restricted space will have less opportunity for exercise. This less active lifestyle means it is much harder for indoor cats to retain their natural shape than outdoor cats.

The first requirement for an indoor cat is to avoid the over-feeding which can lead to obesity, itself a major cause of a number of related health problems including an increased risk of diabetes. Over-feeding is especially widespread amongst owners who like to leave food for their cat during the day - if they are out at work for example. In this case, it’s advisable to only provide a measured amount of food which meets your cat’s energy needs - and nothing more. 

Because you will spend more time with an indoor cat, you're more likely to notice the effect a diet has on your pet's health: the beauty of the coat, bright eyes, digestibility of the food, and the smell and nature of faeces and urine in the litter box for example. These can all be useful pointers as to the effectiveness of the diet you are feeding. In fact, as well as being more prone to weight gain, indoor cats are exposed to two of the high risk factors for urinary problems and cystitis – constant litter tray use and obesity.

As you would expect, there is a range of commercially-produced cat foods developed for the specific needs of indoor cats.

• High in protein and low in fat to help convert calories into lean tissue.
• They contain a controlled balance of minerals to minimise the risk of urinary problems.
• High levels of indigestible fibre to help lower calorie content, as well as helping to ease swallowed hair along the digestive system rather than forming hair balls.
• Special fermentable fibre reduces litter box odours by optimising gut bacteria.
• Highly digestible ingredients help to form small firm faeces which are easily cleaned.
• Indoor cat foods are also high in sources of the nutrients important in maintaining a healthy skin and coat.