A Weight-Loss Feeding Plan for Cats, in Grams and Calories

Feline weight loss is arithmetic plus patience. Set a target weight from body condition score, feed about 80 percent of the resting energy need for that target, and aim for 0.5 to 1 percent of body weight lost per week. Faster than that in a cat risks hepatic lipidosis, a fatty liver failure that kills overweight cats which stop eating. A 6 kg cat should drop 30 to 60 g a week, and a full loss takes 4 to 8 months.

Score the cat, then weigh it

Body condition score (BCS) on the 9-point scale is the starting point. A score of 5 is ideal: ribs felt easily under a thin fat layer, a waist visible behind the ribs from above, and a slight belly tuck from the side. Each point above 5 is roughly 10 to 15 percent over ideal weight. A 7/9 cat is about 20 percent over, and a 9/9 cat is 40 percent or more.

Weigh on a baby scale or a kitchen scale with a box, in grams, at the same time of day before meals. Bathroom scales are useless at this size: a 40 g change does not move the needle, and 40 g a week is exactly the goal. Record every weight with the date in one place, because the trend matters more than any single reading.

The calorie number

Resting energy for the target weight is target weight in kg × 70. For loss, feed 80 percent of that: daily kcal = target kg × 70 × 0.8. Use the target weight, never the current one. Feeding to current weight is the most common reason a diet fails, because a 7 kg cat fed for 7 kg will hold 7 kg forever.

The formula is a starting estimate, not a law. Adjust it against the scale: if the cat loses 1.5 percent a week, add 10 percent of calories; if nothing moves in 3 weeks, cut 10 percent.

Current weight	BCS	Target weight	Daily kcal	Weekly loss goal
4.5 kg	6/9	4.0 kg	224	23–45 g
5.5 kg	7/9	4.6 kg	258	28–55 g
6.5 kg	8/9	5.2 kg	291	33–65 g
7.5 kg	9/9	5.6 kg	314	38–75 g

Why the speed limit matters

A cat that mobilizes fat faster than its liver can process it develops hepatic lipidosis. Fat floods the liver, bile flow slows, and the cat turns jaundiced and stops eating. It is most often triggered by an overweight cat eating less than half its usual intake for 3 to 4 days, or nothing at all for 2 to 3 days. Crash diets, 50 percent cuts, and "starve it thin" plans are dangerous in this species for that reason alone.

One percent of body weight per week is the ceiling, and 0.5 percent is safer for cats over 7 kg or over 10 years old. Weigh weekly during the first month; if the cat drops 300 g in one week when the target was 60 g, raise calories back to the previous level and call the vet.

Plateaus and the 10 percent rule

Weight loss stalls for a real reason: a lighter cat burns fewer calories, so the same portion slowly becomes maintenance. Expect a plateau every 3 to 4 weeks, and expect it to feel like failure when it is just physics.

If weight is unchanged at 3 weigh-ins in a row, cut the daily ration by 10 percent once, not 20. From 291 kcal that is 262 kcal. Recheck after 2 weeks before touching it again. Do not push below 80 percent of resting energy for the target weight without veterinary supervision, because nutrient gaps and muscle loss start there, and muscle is what keeps an old cat walking.

Meals, moisture, and treats

Split the ration into at least 3 meals, or 4 to 6 small ones. A cat on one meal a day spends 20 hours hungry and wakes the house at 4 a.m. Weigh portions in grams: cup measures differ by up to 30 percent between brands and kibble shapes, which is enough to erase a 10 percent deficit.

Wet food helps the plan work. It is roughly 75 to 80 percent water, so the same calories fill more stomach, and the extra water supports bladder health. A 3 oz (85 g) can of pâté usually carries 70 to 90 kcal, so a 291 kcal day is about 3.5 cans, or a measured mix of wet and dry. If you are choosing between the two formats, the comparison in wet vs dry food covers volume, cost, and dental claims.

Keep treats at 10 percent of daily calories or less. On this plan that is 29 kcal, about 6 small freeze-dried chicken cubes or 2 dental chews. Subtract them from the ration instead of adding them, and use a puzzle feeder for part of the meal so the food takes 10 minutes instead of 2; see treats and calorie budget for the exchange values of common extras.

Multi-cat households

Most diets fail at the second bowl. Feed in separate rooms with the doors shut for 20 minutes, and pick up what is left. If that is impossible, a microchip feeder that opens only for the tagged cat solves it, and costs less than a year of prescription food for two cats.

Never top up a communal dry bowl. Measure the household's whole daily total once each morning into a container, and feed only from that container. Put the slim cat's bowl down first and in a spot the dieter cannot reach, and give the dieter its meal behind a closed door while the other cat eats.

What needs a vet

Stop the plan and call if the cat refuses food for 24 hours, vomits more than twice in a day, turns yellow at the gums, ear leather, or eye whites, or seems weak. Book a check before starting if there has been no blood work in a year: diabetes, chronic kidney disease, and arthritis all change the numbers, and undiagnosed arthritis is a common reason an overweight cat will not move enough to lose anything.

Your first month

1. Score BCS, weigh in grams, write both down with the date.
2. Set the target weight, then kcal = target kg × 70 × 0.8.
3. Weigh the daily ration once and bag it; feed only from that bag.
4. Weigh the cat weekly, same day, before the first meal.
5. After 3 flat weeks, cut 10 percent, never 20.

A cat that reaches its target weight still needs a maintenance number, usually the full resting energy for that weight, or it will climb back within a year. The long-term view, including how to keep it off, is in obesity and weight loss.

Frequently asked