Helping your cat lose weight and stay healthy

Worried your cat might be gaining too much weight? We look at how to help your cat slim down safely, while supporting their overall health and wellbeing.

Cats are very good at training their humans. Extra treats, second helpings and topping up bowls can easily become part of daily life. Over time, those small extras can lead to noticeable weight gain – often before you realise it’s a problem. Your vet may mention it during a routine check-up, or you might notice your cat is less active or struggling to groom properly.

A cat is considered overweight when they’re around 10–20% above their ideal weight. Anything beyond that is classed as obesity. Even a small amount of excess weight can affect a cat’s health, mobility and quality of life. Understanding how to spot weight gain early and take gentle action can make a big difference.

Another way to make a big difference is with lifetime cat insurance.

Also see our guide to helping your dog lose weight healthily.

What should my cat weigh?

A cat’s ideal weight depends on more than just breed. Body type, size and muscle mass all play a role. This is why weight charts alone aren’t always reliable. Instead, body condition scoring (BCS) is used to assess how much body fat your cat is carrying.

BCS focuses on your cat’s shape and how easily you can feel certain bones. It’s quick to check and can be done at home once you know what to look for. If you’re unsure, your vet can help you understand what a healthy body condition looks like for your cat.

You can also find visual body condition scoring charts from the Association for Pet Obesity Prevention.

How can I tell if my cat is overweight?

When checking your cat’s body condition, pay attention to:

• Waistline – When viewed from above, your cat should have a visible waist behind the ribs.
• Ribs and spine – These should be easy to feel with gentle pressure, without thick fat covering.
• Abdomen – From the side, the belly should slope upwards towards the back legs rather than hanging down.

Checking your cat’s shape once a month can help you spot changes early. Cats are often weighed less frequently than dogs, so regular at-home checks are particularly useful.

Causes and warning signs of obesity in cats

Your cat may be overweight if you notice:

• Little or no visible waist when viewed from above
• A rounded or sagging belly
• Ribs and spine that are difficult to feel
• Fat deposits around the lower abdomen or base of the tail
• Weight that is at least 10% above their ideal range

Common causes of weight gain in cats include:

• Overfeeding, particularly free-feeding dry food
• Feeding high-calorie diets or too many treats
• Low activity levels, especially in indoor cats
• Neutering, which can reduce calorie needs
• Increasing age and slower metabolism
• Medical conditions such as hypothyroidism or arthritis

Why keeping your cat at a healthy weight matters

Excess weight puts cats at risk of serious health problems, including diabetes, arthritis, heart disease and urinary issues. Obesity can also make grooming difficult, leading to skin problems and matting.

Overweight cats may be less playful, less mobile and more prone to stress. In severe cases, obesity can reduce life expectancy and overall quality of life.

Other risks include:

• Increased anaesthetic risk
• Reduced mobility and joint strain
• Difficulty jumping and climbing
• Heat intolerance
• Higher likelihood of urinary tract disease
• Increased strain on internal organs

Practical ways to help your cat lose weight

Before making changes, it’s important to speak to your vet to rule out medical causes of weight gain.

If weight loss is recommended, a safe plan usually focuses on:

• Measuring food accurately rather than topping up bowls
• Reducing calorie intake gradually, not suddenly
• Feeding a diet suited to your cat’s age, lifestyle and whether they’re neutered
• Switching to a weight-management or lower-calorie food if advised
• Establishing set meal times instead of free-feeding
• Ensuring everyone in the household follows the same feeding plan
• Encouraging regular, gentle activity appropriate for your cat

Consistency is key – small, steady changes are more effective than drastic ones.

Choosing the right food for an overweight cat

Weight-loss diets for cats are designed to be lower in calories while still providing essential nutrients. Your vet may recommend a specific food for a set period and monitor progress.

Treats should be limited and counted as part of your cat’s daily calorie intake. If treats are needed, look for low-calorie options or reduce meal portions to compensate.

Avoid feeding certain human foods, as many items are high in fat and unsuitable for cats. Showing affection through play, grooming or quiet time together is often far more beneficial than extra snacks.

Portion sizes for safe weight loss

If your cat is on a prescription or calorie-controlled diet, follow feeding guidelines carefully.

For other diets, weighing food portions is far more accurate than using cups or estimating. Any treats should be deducted from the total daily allowance.

Food puzzles, slow feeders or dividing meals into smaller portions throughout the day can help keep your cat satisfied while reducing overall intake.

Encouraging exercise and activity

Increasing activity helps burn calories and improves mobility, especially for indoor cats.

Simple ways to encourage movement include:

• Short, frequent play sessions using wand toys or laser pointers
• Hiding small amounts of food around the house to encourage foraging
• Providing climbing opportunities such as cat trees or shelves
• Rotating toys regularly to keep interest high

Aim for several brief play sessions each day rather than one long session, as cats naturally prefer short bursts of activity.

Managing weight in kittens

Weight management in kittens needs special care, as they’re still growing. Restricting food too much can affect development.

If a kitten is gaining weight rapidly, speak to your vet before making changes. In many cases, adjusting feeding routines, reducing treats and encouraging play is enough without strict calorie reduction.

Find out about fun cat enrichment ideas.

Helping an elderly or arthritic cat lose weight

Weight loss in older or arthritic cats should always be approached carefully and under veterinary guidance.

Supportive strategies may include:

• Gradual portion reduction
• Diets higher in protein to maintain muscle mass
• Including omega-3 fatty acids to support joints
• Encouraging low-impact movement, such as gentle play on the floor
• Keeping routines consistent to reduce stress

Avoid sudden changes, as older cats can be sensitive to dietary disruption.

How quickly should cats lose weight?

Healthy weight loss in cats is slow and steady. A typical target is around 0.5–1% of body weight per week.

Rapid weight loss can be dangerous for cats and may lead to serious liver problems. Always follow veterinary advice and monitor progress using body condition scoring as well as weight.

With patience and consistency, most cats can reach a healthier weight and enjoy a more active, comfortable life.

You can also help protect your cat from unexpected veterinary costs with flexible cat insurance from Petgevity.