How much should I feed my cat to lose weight?

The resting requirement of the weight it should be: 198 kcal a day for a target of 4 kg, 234 for 5 kg. On a 3,300 kcal/kg weight-loss kibble the 4 kg target is 60 g a day; on 90 kcal pouches alone it is 2.2 pouches. The target is set with the vet from body condition, not from the number on the scale today.

How fast should a cat lose weight?

0.5-2% of body weight a week (AAHA 2021), and most plans sit in the lower half: 25-50 g a week for a 5 kg cat. Faster than 2% risks hepatic lipidosis and loses muscle. A 5 to 4 kg plan takes about 45 weeks at 0.5% and 22 at 1%; the 11 weeks at 2% is the ceiling, not the goal.

How long will it take my cat to lose 1 kg (2 lb)?

From 5 kg to 4 kg: about 22 weeks at 1% of body weight a week, 45 at 0.5%. The percentage is of the current weight, so the loss slows as the cat gets lighter, which is why a kilogram takes closer to six months than to three.

Is it safe to cut my cat's calories by 30%?

Cut to a target, not by a percentage. The diet line for a 4.5 kg target is 19% below what a 6 kg indoor cat eats now, and that is about as far as a plan goes in one step; a 30% cut of a maintenance food also removes 30% of its protein and vitamins, which a weight-loss food avoids. Never cut below the target-weight requirement, and never to nothing.

What is hepatic lipidosis, and how do I avoid it?

Fatty liver: when a cat, especially an overweight one, eats too little for several days, fat is mobilised faster than the liver can process it and the liver fails. It is avoided by gradual cuts, by never fasting a cat, and by watching intake: a cat that has not eaten for 24-48 hours, on a diet or not, needs a vet the same day.

Should I buy a weight-loss cat food, or just feed less of the current one?

If the diet calories in the table are within about 10-15% of what the cat eats now, less of the same food is fine. Beyond that a therapeutic weight-loss food (higher protein per calorie, more fibre, fewer kcal per kg) keeps the nutrients whole while the calories drop, and the extra bulk helps a cat that is used to a full bowl.

How often should I feed my cat during a diet?

Three or four small meals, or a timed feeder: at the 4 kg target on a 3,300 kcal/kg food that is 15 g four times a day. Small meals blunt the begging and keep the cat eating something every few hours, which is the safest pattern for a cat losing weight.

How do I know what my cat's ideal weight actually is?

Body condition, scored by the vet on the 9-point scale: ribs felt under a thin layer of fat, a waist behind the ribs from above, a slight tuck from the side. Each point above 5 is roughly 10-15% over ideal, so a 6 kg cat scored 7 has a target near 4.5-5 kg. Agree the number with the vet before the diet starts.

How many calories should a cat eat to lose weight?

A cat that should weigh 4 kg (8.8 lb) is fed about 198 kcal a day to lose weight: the resting energy requirement of the target weight (AAHA 2021), whatever it weighs now. For a 6 kg cat aiming at 4.5 kg that is 216 kcal, 19% below what it eats today on the indoor line. The tables turn the target into grams of kibble and pouches, show how many weeks a safe plan takes at 0.5, 1 and 2% of body weight a week, and cover the one rule that matters more for cats than dogs: slowly, and never by starving.

Open the cat food calculator

Diet calories by target weight

The diet line is the resting energy requirement, 70 x kg^0.75, of the weight the cat should be. Read the row for the target, not for today. The two right-hand columns are what the cat will eat once it is there: the indoor line for a neutered house cat, the lean line for an active one.

Calories a day for a cat that should lose weight
Target weight	Weight-loss diet	Indoor line at target	Lean line at target
3 kg (6.6 lb)	160	202	209
3.5 kg (7.7 lb)	179	215	231
4 kg (8.8 lb)	198	226	253
4.5 kg (9.9 lb)	216	237	274
5 kg (11 lb)	234	247	294
5.5 kg (12.1 lb)	251	257	313

How long a plan takes

AAHA 2021 allows 0.5-2% of body weight a week for cats and most plans run at 0.5-1%. The cut column is the diet calories against what the cat eats now on the indoor line; the weeks compound because the percentage is of the current weight. Expect the slow column and be pleased with the middle one.

Weeks to reach the target at 0.5%, 1% and 2% of body weight a week
Plan	Diet kcal a day	Cut from now	Weeks at 0.5%	Weeks at 1%	Weeks at 2%
4.5 kg to 4 kg	198	17%	23	12	6
5 kg to 4 kg	198	20%	45	22	11
5.5 kg to 4.5 kg	216	16%	40	20	10
6 kg to 4.5 kg	216	19%	57	29	14
6.5 kg to 5 kg	234	15%	52	26	13
7 kg to 5.5 kg	251	11%	48	24	12

Grams and pouches a day at the diet calories

The same calories as kibble and as pouches. Weight-loss kibbles are lighter (around 3,300 kcal/kg) than ordinary adult food (3,800), so the portion looks bigger for the same calories; pouches are 85 g at 90 kcal. Weigh the kibble on a kitchen scale, count the pouches, and take any treats (under 10% of the day, 20 kcal at the 4 kg target) out of the total.

Daily portion at the diet calories, by target weight
Target weight	Diet kibble, 3,300 kcal/kg (g)	Adult kibble, 3,800 kcal/kg (g)	Pouches only (90 kcal)	Half wet + kibble (3,800)
3 kg (6.6 lb)	48	42	1.8	0.9 + 21 g
3.5 kg (7.7 lb)	54	47	2	1 + 24 g
4 kg (8.8 lb)	60	52	2.2	1.1 + 26 g
4.5 kg (9.9 lb)	66	57	2.4	1.2 + 28 g
5 kg (11 lb)	71	62	2.6	1.3 + 31 g
5.5 kg (12.1 lb)	76	66	2.8	1.4 + 33 g

Slowly, and never by starving

Cats are the one species where a diet can go badly wrong on its own. An overweight cat that stops eating, because the new food is refused or the cut was too steep, can develop hepatic lipidosis within days. So: move to the diet calories over a week, not overnight; switch foods gradually (a quarter new, half, three quarters, then all); and if the cat eats nothing for a day, stop the plan and call the vet. Weight coming off faster than 2% a week is also a reason to feed more, not less.

Running the plan

Vet first: the ideal weight, a body condition score and, for an older cat, blood work, because thyroid and kidney disease change the plan. Then weigh the cat weekly on the same scale (bathroom scale with and without the cat is fine at this precision), write it down, and adjust by 5-10% if the line is flat for three weeks or falling too fast. At the target, move to the indoor line for that weight in how many calories does a cat need per day, and let the cat food calculator do the grams and pouches for your own food, including the weight-loss line.

Frequently asked questions

How much should I feed my cat to lose weight?: The resting requirement of the weight it should be: 198 kcal a day for a target of 4 kg, 234 for 5 kg. On a 3,300 kcal/kg weight-loss kibble the 4 kg target is 60 g a day; on 90 kcal pouches alone it is 2.2 pouches. The target is set with the vet from body condition, not from the number on the scale today.
How fast should a cat lose weight?: 0.5-2% of body weight a week (AAHA 2021), and most plans sit in the lower half: 25-50 g a week for a 5 kg cat. Faster than 2% risks hepatic lipidosis and loses muscle. A 5 to 4 kg plan takes about 45 weeks at 0.5% and 22 at 1%; the 11 weeks at 2% is the ceiling, not the goal.
How long will it take my cat to lose 1 kg (2 lb)?: From 5 kg to 4 kg: about 22 weeks at 1% of body weight a week, 45 at 0.5%. The percentage is of the current weight, so the loss slows as the cat gets lighter, which is why a kilogram takes closer to six months than to three.
Is it safe to cut my cat's calories by 30%?: Cut to a target, not by a percentage. The diet line for a 4.5 kg target is 19% below what a 6 kg indoor cat eats now, and that is about as far as a plan goes in one step; a 30% cut of a maintenance food also removes 30% of its protein and vitamins, which a weight-loss food avoids. Never cut below the target-weight requirement, and never to nothing.
What is hepatic lipidosis, and how do I avoid it?: Fatty liver: when a cat, especially an overweight one, eats too little for several days, fat is mobilised faster than the liver can process it and the liver fails. It is avoided by gradual cuts, by never fasting a cat, and by watching intake: a cat that has not eaten for 24-48 hours, on a diet or not, needs a vet the same day.
Should I buy a weight-loss cat food, or just feed less of the current one?: If the diet calories in the table are within about 10-15% of what the cat eats now, less of the same food is fine. Beyond that a therapeutic weight-loss food (higher protein per calorie, more fibre, fewer kcal per kg) keeps the nutrients whole while the calories drop, and the extra bulk helps a cat that is used to a full bowl.
How often should I feed my cat during a diet?: Three or four small meals, or a timed feeder: at the 4 kg target on a 3,300 kcal/kg food that is 15 g four times a day. Small meals blunt the begging and keep the cat eating something every few hours, which is the safest pattern for a cat losing weight.
How do I know what my cat's ideal weight actually is?: Body condition, scored by the vet on the 9-point scale: ribs felt under a thin layer of fat, a waist behind the ribs from above, a slight tuck from the side. Each point above 5 is roughly 10-15% over ideal, so a 6 kg cat scored 7 has a target near 4.5-5 kg. Agree the number with the vet before the diet starts.

How much wet food to feed a cat per day?
Pouches and cans a day for cats from 3 to 6 kg, wet only or half wet, half dry, for pouches labelled 70 to 110 kcal, plus the grams of kibble to add.
How many calories does a kitten need? How much to feed a kitten by age and weight
A 12-week, 1.2 kg kitten needs about 214 kcal a day (178 kcal per kg, NRC 2006). Calories by age in weeks and months, per kg and per lb, pouches and cups.
How many calories does a cat need per day?
Calories a day for cats from 2 to 8 kg: resting requirement, indoor and neutered, lean and active, the WSAVA chart range and the weight-loss target.
How much dry food to feed a cat per day? Grams by weight
Grams and cups of dry food a day for 3 to 6 kg cats, and how many grams in a cup of dry cat food: 92 to 113 g on five US labels. Per meal and per bag.

Sources

NRC 2006, Nutrient Requirements of Dogs and Cats — adult, puppy and kitten energy equations
WSAVA, Calorie Needs for Healthy Adult Dogs (July 2020) — chart range for dogs
WSAVA, Calorie Needs for Healthy Adult Cats (July 2020) — chart range for cats
AAHA 2021 Nutrition and Weight Management Guidelines — weight loss at the resting requirement of the target weight

Published 2026-09-17, last updated 2026-09-17. Figures are starting points from the published equations: individual animals vary by up to 30%, so adjust by body condition and ask your vet for puppies under 8 weeks, pregnancy, lactation or any illness.