Is my cat overweight?

Body condition scoring

The 9-point body condition score (BCS) is the standard for cats; 5/9 is ideal. At 5, the ribs are palpable with slight fat cover, there is a visible waist behind the ribs when viewed from above, and a minimal abdominal fat pad. Scores of 6 to 7 are overweight, 8 to 9 obese. Each point above 5 corresponds to roughly 10% above ideal body weight. Owners can check by feeling the ribs, looking for a waist from above, and looking at the belly from the side.

Source: WSAVA Global Nutrition Committee, Body Condition Score chart (cats)

Most owners can’t see their cat is overweight

Most overweight cats look normal to the people who love them. In the APOP 2022 clinical survey, vets classified 61% of US cats as overweight or obese, but 28% of owners of those cats described them as ‘normal’, and only 49% had discussed weight with their vet in the past year. The 2024 APOP owner survey found only 33% of cat owners rated their own cat overweight, only 40% were familiar with body condition scoring, fewer than 30% could recall being given a BCS by a vet, and 53% had at some point tried to help their cat lose weight. None of this is a character flaw; weight gain of 100 g a month is invisible day to day, and long or fluffy coats hide it. That is why a hands-on check (feel the ribs, look for a waist from above, look for a belly tuck from the side) and a monthly weigh-in on a baby scale beat eyeballing.

Source: Association for Pet Obesity Prevention 2022 clinical survey and 2024 owner survey

How common is feline obesity

In the 2022 survey, 61% of US cats were classified as overweight or having obesity. Excess weight in cats is associated with diabetes mellitus, osteoarthritis, urinary disease and reduced lifespan. Neutered, indoor and middle-aged cats are at highest risk. Because most affected cats look normal to their owners, a hands-on body condition check is more reliable than eyeballing.

Source: Association for Pet Obesity Prevention, 2022 U.S. Pet Obesity Prevalence Survey

What extra weight does to a cat

Extra weight is not cosmetic. In Scarlett and Donoghue’s cohort of 1,457 cats followed for 4.5 years across 27 hospitals, obese cats had 3.9 times the risk of diabetes, 4.9 times the risk of needing care for lameness and 2.3 times the risk of skin disease. A 2026 review in Frontiers in Veterinary Science adds that obesity is the major risk factor for feline diabetes, that obese cats are almost twice as likely to show joint disease, and that overweight cats have around four times the risk of lower urinary tract disorders. The same review lists the drivers: neutering (the largest), predominantly dry food (2.4 times the risk of wet), more than 50% dry food from weaning, male sex (2.8 times the odds) and indoor confinement.

Source: Scarlett & Donoghue 1998, JAVMA (1,457 cats); Frontiers in Veterinary Science 2026 review

Weigh a cat at home

Most owners can’t see a 10% weight change. A scale can. Every two weeks is the rhythm that catches drift, and every week for a growing kitten.

1. Bathroom scale: weigh yourself, weigh yourself holding the cat, subtract. Same scale, same time of day.
2. Better: a baby scale or a kitchen scale with a box on it. Accurate to 10 g, which is what you need for a 4 kg animal.
3. The trend matters more than any single number.
4. A change of more than 5% in a month without a plan is a vet mention, up or down. Kittens are the exception: they’re meant to gain.

Source: WSAVA Global Nutrition Committee; AAHA/AAFP 2021 Life Stage Guidelines

Safe weight loss for cats

Cats should lose weight slowly, about 0.5 to 2% of body weight per week. Rapid weight loss or sudden fasting can trigger hepatic lipidosis (fatty liver), a serious condition. Feed a measured amount of a complete and balanced diet, use a kitchen scale or measuring cup rather than a scoop, split food into several small meals, and re-weigh every two weeks. Any weight-loss plan should be agreed with the cat’s vet, especially for cats with health conditions.

Source: WSAVA Global Nutrition Committee; Cornell Feline Health Center, “Obesity”

What a real weight-loss programme looks like

Guidelines put safe feline weight loss at 0.5 to 2% of body weight per week with a check-in every two to four weeks; faster loss risks hepatic lipidosis, which typically follows three or four days of not eating. The realistic picture comes from the only detailed outcome cohort (62 UK cats): 45% completed the programme, completers lost a median 18% of starting weight at about 0.7% a week over a median 177 days, and the rate of loss was by far the strongest predictor of finishing (odds ratio 158). The main reason cats dropped out was that the clinic could not reach the owner, not that the diet failed. A 413-cat international study saw only 5% reach target within the study window. So: pick a target with the vet, weigh weekly, aim for slow and boring, expect it to take six months, and treat a stall as a reason to check in, not to quit.

Source: Frontiers in Veterinary Science 2026 review; Flanagan et al. 2018 (62-cat UK cohort, PMC6295068); PLOS ONE 2018 (413 cats)