Obesity is an increasingly prevalent disease of cats (and also dogs) in the UK, with an estimated 40-50% of UK cats being overweight or obese. Obesity is actually the most common nutritional disorder of pet cats in the UK. It can contribute both directly and indirectly to a whole host of health and lifestyle problems. Thankfully, owners can make a huge difference, implementing a controlled weight-loss regime that will hugely increase the quality of life of their cat. There are multiple things an owner can do to help their cat lose weight in a controlled way. Which we are going to look at now in this blog.

Firstly I will mention why it’s a problem that needs tackling. Obesity is in itself classified as a disease and is also associated with a number of other diseases and “comorbidities” (other health problems) that can affect your pet. Including diabetes mellitus, arthritis, liver disease, cardiac and respiratory problems, cystitis, dermatitis, various cancers, metabolic complications, and a shorter lifespan. Excess body weight therefore dramatically reduces the health and welfare of your cat, in a variety of ways affecting multiple body systems.

Is my cat overweight or obese?

One of the first steps to helping your cat lose weight is recognising that it needs to in the first place! If you are unsure as to whether your cat is overweight, there are a few practical things you can do to gain a better idea before talking to your vet.

Firstly observe the general shape of your cat. Overweight and obese cats tend to be round and lacking a defined waist. You may also see a downpouching or flap underneath the abdomen which is an indicator of excess body fat. You can now try feeling your cat’s bony prominences like the ribs, spine, and hipbones. If you are struggling to feel these or cannot feel them at all then this is an indicator of an overweight or obese cat. 

There are multiple parameters and definitions for obesity depending on who you listen to:

As a general rule, UK recommendations for pet obesity are becoming more and more strict; in order to tackle the hugely widespread problem. By some definitions, cats with obesity have at least 20% excess weight compared to what would be expected for their body size and breed. Cats with a body condition score (BCS) of 8 or 9 out of 9 are classified as obese when examined by vets (with the ideal BCS being a 5). To compare, overweight cats by this classification would have between 10 and 20% excess body weight and a BCS of 6 or 7 out of 9.

At the end of the day, excess weight is a very personal problem! 

It varies from individual to individual with a number of factors playing a role; including breed, neuter status, age, activity level (for instance indoor vs outdoor cats), pregnancy, and prescribed medications. Some significant and life-limiting diseases such as metastatic neoplasia and end-stage liver and kidney diseases are actually not compatible with a weight reduction programme. As such, each cat requires a tailored solution. Which can be provided by speaking to your vet or (especially!) vet nurse. Who can not only gauge the extent of the problem but also which approach to take to tackle it.


Now we are on to the things you can do as an owner to help your obese cat lose this excess weight. Starting with the energy intake part of the equation. Diet is the single most important factor in a successful weight loss and subsequent weight management programme in obese cats. 

It is important when it comes to feeding your pet cat that you choose a high-quality diet. And feed your cat the right amount for its age and level of activity. Decreasing calorie intake enabling steady weight loss whilst still ensuring your cat is gaining all the required nutrients is easily achieved with prescription diets your veterinary team can recommend for you. These diets are usually low fat, or high protein, and low carb. There are a variety of wet and dry food options owners can choose from, depending on which type your cat is already accustomed to. Thus making the transition to the new diet easier. Specially formulated weight loss foods avoid nutrient deficiencies. They also help to prevent weight regain after the target weight has been achieved. 

Alternatively, you can feed your cat the same food it is currently eating. But reduce the amount you feed it by about 20%. Whilst this too can be effective and result in a successful weight loss, it is important to note that your cat may be left feeling unsatisfied between meals.

Diet planning

When it comes to making a diet plan, one which is gradual and gentle is preferred. So as to encourage fat rather than muscle loss, and at a safe rate. Obesity usually occurs by being in a positive energy balance for a prolonged period of time. As such it will take a long period of energy intake restriction to re-achieve ideal weight. The process can take several months. Regular monitoring with weight checks can be helpful to see if your cat is on the right track. 

A crash diet is a bad idea because it can trigger fatty liver disease (hepatic lipidosis). Which is serious and even potentially fatal. We usually aim to keep weight loss to about 1-2% of bodyweight per week.

The provision of treats should also be minimised. It can be helpful to have the whole family on board. This is so that you can be sure your cat’s progress isn’t going to be derailed by someone who is perhaps being a bit too generous with the biscuits! Always providing ample water too can help to keep your cat feeling full. And is especially important for dry food diets. For other weight loss tips see this blog


Whilst increasing exercise does not in its own right contribute significantly to weight loss in cats, it does have the benefit of decreasing muscle loss. Thus ensuring weight loss by your pet is likely to be in the form of fat. It can also speed up the metabolism of your cat thus increasing the success of the diet.

It is of course a bit trickier for cats than dogs to increase activity levels. But a few simple things you can do every day include increasing the amount of playtime, especially for indoor cats, and encouraging movement outdoors. Invest in some new toys (especially things to chase like laser pointers and wand toys) and climbing posts. Sit in your garden if the weather is nice to encourage your cat to run around outside. Some owners even manage to get their cats comfortable with harnesses and take them on walks!

Does it always work? Lastly, I think it’s important to note that it may ultimately not be possible for your cat to reach its ideal weight and BCS and that this can be ok. Even as little as around a 5-10% weight loss can have measurable benefits to your cat’s health and welfare and should be commended. It is certainly better for your cat to lose less weight but in a safe way than more weight in a fast and uncontrolled way! By managing your own expectations about the rate and extent of your pet’s weight loss you better prepare yourself for this long but rewarding process.

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