Start here, because cats are different
Whatever you know about helping a dog lose weight, put it down for a minute. A cat who stops eating, or eats far too little, can develop hepatic lipidosis, where the liver floods with fat it can't process. It can turn fatal within days, and overweight cats are the most at risk. Which is a cruel joke, because they're exactly the cats people put on sudden diets.
So: never crash diet a cat, never fast one, and if she stops eating for two days, call the vet. Weight comes off cats slowly and on purpose, or it doesn't come off at all.
First, which way is her weight going?
If she's round and holding steady or gaining, read on.
If she's quietly losing weight without you trying, book a vet appointment instead. Unexplained weight loss in an older cat points to overactive thyroid, kidney disease, diabetes or dental pain, and she may still look chunky while it happens.
There's a sneaky middle version too. Older cats lose muscle while keeping fat, so she can weigh the same as last year and be in worse shape. If her spine and hips feel bonier but her belly is still full, mention that as well.
Is she actually overweight?
Use your hands rather than the scale.
Ribs. With light pressure you should feel them under a thin layer, like the back of your hand. If you have to press to find them, she's carrying too much.
From above. Standing, she should narrow slightly behind the ribs. Straight sides, or wider at the middle, is your answer.
From the side. Her belly should tuck up toward her back legs rather than hang level.
And the bit that confuses everyone: the loose swinging flap on her lower belly is normal. It's a primordial pouch, plenty of slim cats have one, and it isn't fat.
Why this matters for how she moves
Extra weight lands through hips, knees and elbows that probably already have arthritis in them, because most cats past about ten do. So she jumps less, then moves less, then loses the muscle that was supporting those joints, and the cycle tightens.
Body fat also isn't just storage. It produces inflammatory signals that travel round the body, including through sore joints. So the weight is pressing on the problem and feeding it at the same time.
That's why weight loss often does more for a stiff old cat than anything else. And unlike the rest of it, this one is free.
Getting it off, safely
1. See the vet first. Not optional here. She needs bloodwork to rule out thyroid and kidney problems, and she needs a target weight based on her frame rather than a guess. Ask for the actual daily calorie number too.
2. Aim slower than feels productive. Around one percent of her body weight per week is the sort of pace vets aim for. For a 6 kilo cat that's roughly 60 grams a week, which sounds like nothing and adds up properly over six months. Faster is not better. Faster is the thing that causes liver problems.
3. Weigh her food. Measuring cups are wildly inaccurate and a small error repeated twice a day is the whole reason plenty of diets fail. A cheap kitchen scale fixes it.
4. Stop free feeding. A bowl topped up whenever it looks low makes portion control impossible. Move to set meals, two or three a day, measured out.
5. Consider more wet food. It carries a lot of water, which means more volume and more satisfaction for fewer calories. A lot of cats also drink too little in general, so this helps twice.
6. Feed her separately if you have other cats. Otherwise the dieting one eats the other one's dinner and you'll never work out why nothing's changing. Separate rooms at mealtimes works. Microchip feeders work better if it's a long term problem.
7. Cap the treats at ten percent of her daily calories. That includes the dental treats, the licky tubes and whatever she gets when she shouts at six in the morning.
8. Make her hunt a bit. Puzzle feeders, or simply scattering a portion of her dry food so she has to find it. Cats are built to work for small frequent meals, and it burns time and energy that would otherwise go into staring at the bowl. Just keep the hiding places somewhere she can reach without a painful jump.
9. Play in short bursts. Five minutes, a few times a day, is more realistic than one long session. If she's stiff, keep the wand toy low and horizontal rather than making her leap. Chasing along the floor is fine. Twisting midair is not.
10. Weigh her monthly. Same scale, same day of the month, written down. Hold her, weigh yourself, subtract, if that's easier than getting a cat to sit on a scale.
Make it easier for her to move
Weight loss and mobility feed each other, so it's worth removing the obstacles at the same time.
Put steps or a stool where she used to jump. Swap a high sided litter tray for one she can walk into. Move her food and water off the counter and onto the floor if climbing has become an effort. Put a warm bed somewhere out of the draught, because stiffness and cold go together.
None of this is babying her. She'll move more, not less, when moving stops hurting. Our guide to the subtle signs of arthritis in cats covers what to watch for if you're not sure she's sore.
When to stop and call the vet
Ring them if she refuses food or eats noticeably less for two days running, if she seems lethargic or hides more than usual, if she's vomiting or her gums look yellow at all, or if she loses weight much faster than the plan.
A diet that isn't working is a minor setback. A cat who has stopped eating is an emergency.
FAQs
How fast should a cat lose weight?
Slowly. Around one percent of body weight a week is the usual target, under vet supervision. Rapid loss risks serious liver disease.
Can I just feed my cat less?
Not without a plan. Sharp cuts and skipped meals are what trigger hepatic lipidosis. Reduce gradually using a calorie target your vet gives you.
My senior cat is losing weight on her own. Is that good?
No. Unintentional weight loss in an older cat needs investigating, even if she was overweight to begin with.
Will losing weight help her arthritis?
Usually yes, and often noticeably. It reduces the load on sore joints and cuts down the inflammatory signalling that body fat produces.
Is the saggy belly flap fat?
Usually not. That's a primordial pouch and it's normal feline anatomy. Judge her by her ribs and waist instead.
Educational content only, not a substitute for veterinary advice. Always have your vet set your cat's weight target and calorie allowance, and never restrict a cat's food without veterinary guidance. These statements have not been evaluated by the Food and Drug Administration. PCQ Pet is a dietary supplement and is not intended to diagnose, treat, cure, or prevent any disease. Individual results vary.