Cats can have a habit of putting on a few pounds, especially as they get older and less active or if they are kept exclusively indoors. Obesity is the most common nutritional disorder in cats, affecting around one in three in the UK adult population. Therefore it's important to monitor your cat's weight and body condition regularly, as overweight cats are particularly prone to health issues including diabetes, osteoarthritis, lower urinary tract problems and constipation.

How to tell if your cat is overweight

It can be tricky to tell if your cat is overweight. For reference, use the Body Condition Chart. Regular assessments by your vet are recommended, but to check yourself simply run your hands around your cat’s flanks and abdomen. At ideal weight you should be able to feel, but not see, their ribs quite easily, without a heavy covering of fat. Their waistline behind the ribs should be clearly visible when looking down from above, with no sign of swaying folds at the sides when they walk.

• Your cat is moderately overweight - if the waistline is not clear or hard to see, you can feel some fat under the tummy, but you can still just feel the ribs under a layer of overlying fat.
• Your cat is obese - if there is no waistline, you can’t feel the ribs and the tummy looks rounded with a heavy, hanging covering of fat (fat pad) that sways when they walk.

Before embarking on any dietary changes or ‘weight-loss programme’, consult your vet. It is important your cat is weighed and checked over for any underlying disease problems before any dietary change or restriction.

Cut out treats and snacks

To help your cat lose weight, start by cutting out all treats and titbits, including milk, for a period of two weeks. Make sure everyone else in the family knows the rules so there’s no affectionate cheating! If you have several cats, feed your overweight cat separately to avoid stealing. Dividing the cat’s food into smaller frequent meals may help with hunger, and keep track of what, and how much, you are feeding. Your vet may suggest reducing the amount you are feeding or a special, lower-calorie diet. Remember never to ‘starve’ your cat or restrict food without veterinary advice as this can lead to serious medical problems.

After a fortnight, check the body condition again and continue the diet until an ideal body condition and weight is reached. Remember that rapid weight loss is dangerous and can indicate a serious underlying problem. You may be able to join a weight-loss programme run by your vet to allow close monitoring of your cat’s weight loss along with help and advice.

Once you've succeeded, you may want to slightly adjust feeding quantities to stabilise weight.

Light formulas

You should also consider the benefits of moving your cat onto a specially formulated 'light' food. Light diets are less concentrated, with a lower calorie content, so you may not need to cut down on the actual amount you feed. These diets are enriched in all the essential nutrients but lighter in calories, so even if you do need to reduce feeding quantities you can be sure your cat is continuing to get all the right minerals and vitamins in the correct proportions. Note, however, that if you currently feed your cat a diet recommended by your vet, you should consult them before making any changes.

No 'crash' diets

It is important you never starve your cat as this can result in serious health problems. In fact you should not restrict food intake at all without veterinary supervision. It's not safe to reduce food intake by more than 10-15%, as your cat won't get the right balance of essential minerals and vitamins and could run the risk of developing problems such as ‘hepatic lipidosis’. This is a serious and potentially fatal liver condition caused in some cases by food restriction.

Keep active

Remember that food is only part of the equation. Lifestyle can be important too. Lack of exercise can often be the cause of weight gain, so encourage your cat to stay active and burn up more calories

• A dedicated daily playtime can help and many cats enjoy time spent chasing a ball or using a ‘fishing’ toy.
• Climbing and scratching towers add interest to the cat’s environment as well as encouraging exercise.
• Put some of the daily food allocation into a special feeding ball which the cat needs to spend time rolling to get the food.
• Place food at the top of the stairs or on top of a climbing tower.
• If your cat is kept exclusively indoors think about allowing access outdoors, perhaps by fencing the garden or building a pen outside to encourage more activity.

Successful weight loss should be slow and gradual and can take months, so be patient, take your vet’s advice and, if possible, join a feline weight-loss clinic for extra support.