Obesity in cats

Isolated cat


  • Vets estimate that over a third of cats in the UK are overweight.
  • An overweight cat is at risk of health problems and a shorter lifespan.
  • It’s important to know your cat’s ideal shape and recognise when it changes.
  • You can control your cat’s weight with diet and exercise.
  • Contact your vet for advice if you think your cat is overweight.
  • For more information, download our guide ‘Getting your cat into shape’.

Is my cat overweight?

The best way to assess your cat is to look at their shape; their weight may fluctuate, but their ideal shape is always the same.

  1. Look at your cat from the side and from above. They should have a waist.
  2. Feel under your cat’s tummy. It should curve in, not bulge out.
  3. Feel along your cat’s side and back. You should be able to feel their ribs, spine and hip bones quite easily but they shouldn’t stick out.
  4. Feel the base of your cat’s tail where it meets the spine. There shouldn’t be a build-up of fat.

Keep an eye on your cat’s weight using our body condition score chart.


So, why is your cat overweight?

Diet and exercise:

If your cat has gained weight, it’s likely they are eating too much or moving about too little. ‘Eat less, move more’ – this simple formula really does work.


It’s rare for a medical problem to cause weight gain in cats. However, if your cat has an illness such as heart disease, lung disease or arthritis they may gain weight because they aren’t able to exercise. If you have a female cat that hasn’t been spayed, it’s important to rule out pregnancy.

Health risks

Overweight cats are at risk of:

The best diet for an overweight cat

Read our advice on feeding your cat.


Read our advice on how to exercise your cat and specific advice on exercising an indoor cat.

When to contact your vet

Make an appointment with your vet or vet nurse if you are struggling to keep your cat at a healthy weight, they will be happy to help. Because obesity is so common, many veterinary practices now offer weight clinics.

Your cat should also have regular health checks (at least once a year), at which your vet can check their weight and shape.


We know how difficult it can be to get a pet to lose weight, but trust us, it’s worth it! Once your cat has reached his/her ideal shape, they will be healthier, happier and more active. They will also have the best chance of living a long, healthy life.



Food and treats

Monitor their shape

  • Know what your cat should look and feel like (using our chart) and be sure to check them regularly.
Chart to show cat treats compared to human food.

Cat treats can be very fattening.


An overweight cat is much more likely to develop health problems than a cat in good shape; and as a result, they tend to cost more. To keep your vet bills as low as possible, keep your cat at a healthy weight.

Consider insuring your cat as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them throughout their life.

Published: March 2019

PetWise Pet Health Hub – brought to you thanks to support from players of People’s Postcode Lottery 

Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst