Is My Cat Overweight? A Vetʼs Checklist for Healthy Weight Loss

Weight gain is rarely caused by just one factor — itʼs usually a combination of diet, lifestyle, and biology.

• Overfeeding and calorie-dense diets are the most common culprits. Dry cat food in particular is easy to over-pour, and just a few extra kibbles a day can add up over time.
• Indoor lifestyles reduce activity. Cats kept indoors are safer but often burn fewer calories, especially if they donʼt have regular play or climbing opportunities.
• Medical and mobility issues such as arthritis or urinary tract disease can reduce activity, leading to gradual fat accumulation.

Understanding these factors is the first step to making changes that help.

Because most cats weigh only 4-6kg, even a few hundred grams over ideal makes a big difference. In human terms, half a kilo on a cat is like seven kilos on a person.

At home, you can use simple checks:

• Ribs should be easy to feel under a light layer of fat. You should be able to feel your catʼs ribs with light pressure. If theyʼre hard to locate, your cat may be carrying extra fat.
• A waistline should be visible when viewed from above. A sagging belly or fat pad between the hind legs suggests excess weight.
• The belly should slope upwards toward the hips; a sagging pouch suggests fat deposits.
• Mobility and grooming often decline. Overweight cats may be less inclined to play or jump, displaying reduced energy.

If youʼre uncertain, ask your vet to assess your catʼs BCS at their next check-up.

Thereʼs no single “ideal numberˮ that applies to every cat. A healthy Burmese may weigh 3.5kg, while a Maine Coon can easily exceed 8kg. Because of these breed and size differences, weight charts are only a starting point.

Vets instead use a Body Condition Score (BCS) system, which looks at fat coverage and body shape rather than raw numbers. On a 9-point scale, 5 is ideal, 6-7 indicates overweight, and 8-9 signals obesity. As a guide, cats that are 10- 20% over their ideal weight are considered overweight, and those more than 20% above ideal are obese.

The scale itself matters less than how your cat looks and feels in your hands — which brings us to recognising the signs at home.

Obesity in cats can lead to several health complications, including:

• Hepatic lipidosis (fatty liver disease) can occur if an overweight cat stops eating or loses weight too quickly — a potentially fatal complication unique to cats.
• Diabetes becomes more likely as excess fat disrupts insulin regulation. 
• Arthritis develops earlier and worsens faster when joints bear extra strain, especially in senior cats.
• Overweight cats face a higher risk of cardiovascular issues, like heart disease.
• Quality of life suffers, as overweight cats often tire easily, play less, and become frustrated when they canʼt move or groom like they used to.

Preventing and addressing obesity early is key to safeguarding your catʼs health and improving their quality of life.

Note: This guide focuses on overweight cats. If your cat seems underweight — with visible ribs, spine, or hip bones — that carries different risks such as malnutrition and weakened immunity. Always seek veterinary advice.

Veterinarians take a structured approach to assessing weight, combining hands- on checks with clinical evaluation.

• Physical exam and visual assessment come first. Vets feel for ribs, check the waistline, and note fat deposits along the abdomen, spine, and face.
• Body Condition Score (BCS) charts standardise this process. On the 9-point scale, 5 is ideal, 6-7 is overweight, and 8-9 is obese.
• Weight history provides context. Comparing todayʼs number to previous weigh-ins helps identify gradual trends that owners may not notice.
• Bloodwork may be recommended to rule out or detect conditions linked to weight changes, such as diabetes or thyroid disease.
• Caloric goals are calculated so owners know exactly how many calories per day their cat needs for safe weight loss or maintenance.
• Therapeutic weight loss diets may be prescribed when obesity is severe or linked to other health conditions.

This assessment doesnʼt just confirm whether a cat is overweight — it creates a personalised roadmap for safe, gradual weight management.

Helping your cat lose weight involves a gradual, balanced approach to avoid health complications like hepatic lipidosis. Combining diet changes with interactive play and consistent monitoring is essential.

Cats are natural hunters, and interactive play can mimic their instinctive behaviours while encouraging movement. Strategies include:

• Toys That Mimic Prey: Use toys like Feather Wands, which allow your cat to chase and pounce. Unlike laser pointers, these toys provide the satisfaction of “catchingˮ something.
• Climbing and Exploring: Provide climbing frames, shelves, or safe outdoor enclosures to encourage jumping and exploring.
• Interactive Feeders: Products like the "I am Not a Dog" Indoor Hunting Feeder require cats to hunt for their food, providing both exercise and mental stimulation.

For senior or less active cats, focus on gentle activities that donʼt strain their joints, such as light play sessions or using elevated resting spots that require mild climbing.

Diet is critical in any weight-loss plan for cats. Some effective approaches include:

• Interactive Feeding: Replace static bowls with slow feeders or products that require hunting or problem-solving.
• Switch to Weight-Loss Cat Food: Specially formulated options, such as Satiety or weight management diets, provide essential nutrients with fewer calories.
• Incorporate Wet Cat Food: Wet cat food is often lower in calories than dry food and can help keep cats feeling fuller for longer.
• Keep treats under 10% of daily calories, breaking large ones into smaller portions.

Itʼs essential to monitor portion sizes and avoid rapid weight loss. Regular weigh- ins at home or at your veterinary clinic can ensure your catʼs progress is safe and effective.

Feeding habits play a major role in feline obesity. Even well-meaning pet parents can make missteps that lead to weight creep or stalled progress.

Overfeeding, especially free-feeding dry food or giving excessive cat treats, can lead to unintentional weight gain. Many cats, when bored, will demand food by meowing persistently or knocking objects over. While they appear hungry, theyʼre often just seeking stimulation.

Inactivity compounds the issue. Cats kept indoors or in enclosed spaces may lack opportunities to climb, hunt, or explore. Providing climbing frames, elevated resting spots, and interactive toys can encourage movement.

Tracking your catʼs progress is vital to ensure safe and sustainable weight loss. Regular monitoring helps identify whatʼs working and highlights areas where adjustments may be needed.

Weighing your cat regularly is a key part of monitoring their progress. Cats should lose weight gradually—rapid weight loss can lead to serious health issues like hepatic lipidosis. Hereʼs how to track safely:

• Monthly Weigh-Ins: Use a pet scale or weigh yourself while holding your cat, then subtract your weight.
• Track Trends: Record the weight each time and monitor for consistent progress. A loss of 0.5-2% of body weight per week is ideal.
• Vet Assistance: Veterinary clinics often offer weigh-ins as part of weight management programs, providing additional support and advice.

If your catʼs weight stalls or decreases too quickly, consult your vet immediately to reassess the plan.

As your cat begins to lose weight, their calorie needs and activity levels will change. Adjustments to the weight-loss plan ensure continued progress:

• Reassess Food Portions: Work with your vet to reduce portion sizes or adjust feeding times as needed.
• Introduce New Activities: Keep your cat engaged by adding new toys or play routines.
• Address Behavioural Changes: If your cat becomes more demanding or lethargic, explore ways to keep them mentally stimulated, such as interactive feeders or elevated spaces.

Staying flexible and observant will help you maintain momentum throughout the weight-loss journey.

Your veterinarian plays a critical role in your catʼs weight-loss journey, providing expertise, monitoring progress, and addressing potential health concerns.

Seek veterinary advice if:

• Your cat isnʼt losing weight despite following a calorie-controlled diet and exercise routine.
• Youʼre unsure about the right diet or portions for your cat.
• Your cat has underlying health conditions, such as joint pain, diabetes, or other medical concerns.

Vets can recommend weight-loss programs tailored to your catʼs specific needs, including therapeutic diets and appropriate activity plans.

1. Should I free-feed my cat?

No — cats should not be free-fed because it makes portion control and weight management impossible. Cats that graze on kibble often eat more than they need. Scheduled meals let you measure food accurately, track intake, and prevent obesity.

2. Why is my neutered or middle-aged cat gaining weight so easily?

Cats gain weight more easily after neutering or in middle age because their metabolism slows and activity declines. If you donʼt adjust portion sizes at these stages, slow but steady weight gain is almost inevitable. A switch to a lower- calorie formula or smaller meals can help.

3. How do I manage feeding in a multi-cat household (to stop food stealing)?

Cats in multi-cat households should be fed separately so each one eats only their portion. Shared bowls make it impossible to know whoʼs overeating, and overweight cats often dominate food. Microchip-activated feeders or split mealtimes help keep portions fair.

4. Do cat treats really matter for weight loss?

Yes — cat treats count toward daily calories and can quickly stall weight loss. Keep them under 10% of daily intake and choose low-calorie options like freeze- dried meat or small dental chews.

5. What if my cat refuses weight-loss food or wonʼt eat diet food?

Cats that refuse weight-loss food should be transitioned slowly by mixing old and new food over 7-10 days. If your cat still wonʼt eat, ask your vet about alternative formulas. Forcing a sudden switch is risky for cats.

Helping your cat achieve and maintain a healthy weight is one of the most effective steps you can take for their wellbeing. With structured feeding, regular monitoring, and a little creativity in play, most cats respond well and regain comfort, mobility, and energy.

If your cat is already overweight, this guide gives you a starting point. The next step is choosing a diet designed for weight management.

Explore our vet-approved recommendations in the Best Cat Food for Weight Loss in Australia guide.

Written by Dr Jane Miller