- After neutering, a cat needs fewer calories but often feels hungrier, so slow weight gain is common.
- The portion matters more than the bag. Weigh every meal on kitchen scales.
- Look for a sterilised recipe with high protein, moderate fat and urinary support.
- Add wet food for extra water, and weigh your cat once a month.
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What changes after neutering
Neutering lowers a cat's energy needs, often by around a quarter, and many cats eat more eagerly in the months after surgery. If the food and portion stay the same, the result is gradual weight gain, usually noticed only when a cat is already overweight.
Extra weight matters. Overweight cats are more likely to develop diabetes, joint pain and urinary problems, and they tend to be less active, which makes the problem worse.
What to look for in the food
| Look for | Why it helps |
|---|---|
| A sterilised or light recipe | Made for the lower energy needs of neutered and indoor cats. |
| High protein | Helps keep muscle while calories are controlled. Our sterilised dry foods range from 30% to 42% protein. |
| Moderate fat | Fat is the most calorie-dense nutrient, so less fat means fewer calories per gram. |
| Urinary support | Controlled minerals help, as neutered cats, males in particular, are prone to urinary problems. |
| Fibre | Helps your cat feel full and helps move hairballs through. |
An honest note: in our range, sterilised dry foods have 3,230 to 3,850 kcal per kg, against up to 4,319 for standard adult recipes. That is a real but modest difference per meal. The recipe helps; the measured portion does most of the work.
How much to feed a sterilised cat
A neutered adult cat needs roughly 1.2 times its resting energy (70 × body weight in kg to the power of 0.75). Here is what that means in practice:
| Cat's weight | Calories a day | Original Sterilized, dry | Or Delicat pouches, 70 g |
|---|---|---|---|
| 3 kg | 191 kcal | 53 g | 3.1 pouches |
| 4 kg | 238 kcal | 66 g | 3.8 pouches |
| 5 kg | 281 kcal | 78 g | 4.5 pouches |
| 6 kg | 322 kcal | 89 g | 5.2 pouches |
These are starting points. Weigh your cat every 2 to 4 weeks and adjust the portion by about 10% if the weight moves. For a different food, use our cat food calculator.
Add wet food for water
Cats often drink little, and dry food is only around 10% water or less. Wet cat food in our range is 65% to 85% water, which helps keep urine dilute, one of the simplest ways to support the urinary tract.
You do not have to switch completely. A common routine for a 4 kg cat: one Delicat Sterilized pouch a day (about 62 kcal) plus 48 g of Gosbi Original Sterilized dry food, about 238 kcal in total. Always split the calories, not the grams. Our wet vs dry guide explains how.
Habits that keep a sterilised cat lean
- Weigh, do not scoop. A scoop can be 20% out, or far more. Kitchen scales cost a few dollars.
- Split the day into meals. Two to four small meals suit cats better than a full bowl left out all day.
- Make them work for it. Puzzle feeders and scattered kibble slow eating and add activity.
- Play twice a day. Ten minutes with a wand toy, morning and evening.
- Count the treats. Keep them under 10% of daily calories, and agree one person feeds the cat.
- Weigh monthly. Small changes are easy to fix; big ones are not.
Foods for sterilised cats
Gosbi OriginalSterilizedFrom $9.00$8.10 on subscription
Gosbi ExclusiveChicken & Salmon SterilizedFrom $5.00$4.50 on subscription
Petflakes MaintenanceSterilizedFrom $12.00$10.80 on subscription
Gosbi Exclusive Grain FreeDuck & Fish SterilizedFrom $8.00$7.20 on subscription
Gosbi DelicatSterilized Chicken (pouch)From $1.75$1.57 on subscription
Gosbi DelicatSterilized Chicken & Sardine (pouch)From $1.75$1.57 on subscriptionQuestions
When should my cat switch to a sterilised food?
If your cat is an adult, switch over about a week, using a gradual switch, once they have recovered from surgery. If your kitten was neutered young, ask your vet: most stay on kitten food until around 12 months, with carefully measured portions.
Is sterilised food only for neutered cats?
It is designed for them, and it also suits indoor, less active adult cats. It is not designed for kittens or for pregnant or nursing cats.
Can a sterilised cat eat regular adult food?
Yes, if the portion is measured to their lower energy needs. A sterilised recipe simply makes that easier.
My cat begs all the time since being neutered. What should I do?
This is very common. Split the same daily amount into more, smaller meals, use a puzzle feeder, and add wet food, which gives more volume for the same calories.
This guide is general information for healthy pets, not veterinary advice. If your pet has a health condition, is pregnant, or is losing or gaining weight unexpectedly, talk to your vet.