How fast should a dog lose weight?

One to two percent of body weight a week (AAHA 2021): for a 30 kg dog, 0.3 to 0.6 kg a week. At 1% the 30 to 25 kg plan takes 18 weeks, at 1.5% 12, at 2% 9. Faster than 2% a week usually means the dog is losing muscle as well as fat, or is not eating; slower than 1% means the calories are still too high or the treats are not being counted.

Can I just feed less of the normal food?

You can, but the cut is 36%, and it cuts the protein, vitamins and minerals in the bowl by the same 36%. A weight-loss food has more of those per calorie so the dog gets a full ration of everything except energy, and more fibre so the smaller bowl still fills it up. Ask the vet before starting any diet; some dogs have a medical reason for the weight.

Count them inside the 783 kcal: a 10% allowance is 78 kcal a day, which leaves 704 kcal for food, 207 g instead of 230. Set the day's kibble aside in the morning and use pieces of it as treats; a dog does not know the difference, and the total cannot creep.

My dog is hungry all the time. What can I do?

Split the 230 g into three or four meals instead of two, feed from a slow bowl or a puzzle feeder so the meal lasts longer, and add water to the kibble. Plain green beans or zucchini add bulk for almost no calories. Do not add the calories back unless the four-week check says the dog is losing faster than 2% a week.

What do I feed once the dog reaches 25 kg?

The neutered-adult amount for 25 kg, not for 30: 1,062 kcal a day, 312 g of the same 3,400 kcal/kg food or the grams of any other food from the dog food calculator. Weigh the dog monthly for the first three months; if the scale creeps up by a kilogram, go back to the diet amount for a month.

How to help a dog lose weight: a 12-week plan with the grams

Published 2026-09-22 · 6 min read

A 30 kg (66 lb) dog that should weigh 25 kg is fed about 783 kcal a day for the whole diet: the resting energy requirement of the target weight (AAHA 2021), 36% below the 1,218 kcal a neutered 30 kg dog eats to stay 30 kg. On a 3,400 kcal/kg weight-loss food that is 230 g a day, 115 g a meal, and at 1.5% of body weight a week the 5 kg come off in 12 weeks. Below is the week-by-week weight to expect on the scale, the same plan for other dogs, and what to change at the four-week check.

Dog food calculator

Step 1: pick the target weight

Weigh the dog on the vet's scale and agree the target with the vet from the body condition score (ribs easy to feel, a waist from above), not from a breed chart. The dog in this article weighs 30 kg and should weigh 25. Write the target down; every number that follows comes from it, not from the weight today.

Step 2: the calories, the food, the grams

The diet calories are the resting energy requirement of the target weight, 70 x kg^0.75 (AAHA 2021): 783 kcal a day for a target of 25 kg. Choose a weight-loss food and read its kcal per kg on the bag: at 3,400 kcal/kg that is 230 g a day, 115 g a meal. Weigh it on kitchen scales every time; a scoop is not a measurement. The dog food calculator gives the grams for your own bag from the target weight and the "needs to lose weight" setting.

Step 3: the week-by-week plan

The calories and grams do not change through the plan; what changes is the weight on the scale, which should fall about 1.5% a week. Weigh the dog on the same scale, at the same time of day, once a week, and write the real weight next to the expected one.

Expected weight each week for a 30 kg dog going to 25 kg at 1.5% a week, on 783 kcal and 230 g of a 3,400 kcal/kg food
Week	Weight to expect	Lost so far	Calories	Food a day
Week 1	29.6 kg (65.1 lb)	0.4 kg	783	230 g
Week 2	29.1 kg (64.2 lb)	0.9 kg	783	230 g
Week 3	28.7 kg (63.2 lb)	1.3 kg	783	230 g
Week 4 (check)	28.2 kg (62.3 lb)	1.8 kg	783	230 g
Week 5	27.8 kg (61.3 lb)	2.2 kg	783	230 g
Week 6	27.4 kg (60.4 lb)	2.6 kg	783	230 g
Week 7	27.0 kg (59.5 lb)	3.0 kg	783	230 g
Week 8	26.6 kg (58.6 lb)	3.4 kg	783	230 g
Week 9	26.2 kg (57.7 lb)	3.8 kg	783	230 g
Week 10	25.8 kg (56.9 lb)	4.2 kg	783	230 g
Week 11	25.4 kg (56.0 lb)	4.6 kg	783	230 g
Week 12	25.0 kg (55.1 lb)	5.0 kg	783	230 g

Why the loss slows down near the goal

The plan is a share of the current weight, not a fixed number of grams a week: 1.5% of 30 kg is 0.45 kg in week 1, but 1.5% of 25.4 kg is only 0.38 kg in week 12. That is normal: as the dog gets lighter its own needs fall towards the 783 kcal it is being fed, so the gap that drives the loss closes. Do not cut the food again just because the last weeks are slower than the first, as long as the scale is still moving.

Step 4: the four-week check

Four weeks is long enough to see the trend and short enough to fix it: the plan expects about 1.8 kg off by then. Add up the loss since the start and act on it; the change is 10% of the calories either way, then another four weeks before the next change. If the dog has lost nothing at all, look for the calories first: treats, table food, a second person feeding, the neighbor.

What to do at week 4 for the 30 kg dog, by weight lost since the start
Lost in 4 weeks	Action	New calories	New food a day
Less than 1.2 kg (under 1% a week)	Cut the food by 10%	704	207 g
1.2 to 2.3 kg (1-2% a week)	Keep going	783	230 g
More than 2.3 kg (over 2% a week)	Add 10% back	861	253 g

The same plan for other dogs

Calories today on the neutered-adult line, diet calories from the target weight, grams on the same 3,400 kcal/kg food and weeks at 1.5% a week. The guide to how many calories a dog should eat to lose weight has the same targets for three food densities and at 1% and 2% a week.

Diet calories, grams and weeks by dog, on a 3,400 kcal/kg weight-loss food at 1.5% a week
Dog	Calories today	Diet calories	Food a day	Per meal	Weeks
7 kg to 5.5 kg	409	251	74 g	37 g	16
12 kg to 10 kg	613	394	116 g	58 g	12
18 kg to 15 kg	830	534	157 g	78 g	12
25 kg to 20 kg	1,062	662	195 g	97 g	15
35 kg to 30 kg	1,367	897	264 g	132 g	10
45 kg to 38 kg	1,651	1,071	315 g	158 g	11

Step 5: after the diet

At 25 kg (55 lb) the dog moves to the neutered-adult amount for 25 kg, 1,062 kcal and 312 g of the same food, which is still 156 kcal a day less than it ate at 30 kg. For an older dog the tables in how much to feed a senior dog keep it on the lower lines, and how much should I feed my dog gives the maintenance grams for any bag.

Frequently asked questions

How fast should a dog lose weight?: One to two percent of body weight a week (AAHA 2021): for a 30 kg dog, 0.3 to 0.6 kg a week. At 1% the 30 to 25 kg plan takes 18 weeks, at 1.5% 12, at 2% 9. Faster than 2% a week usually means the dog is losing muscle as well as fat, or is not eating; slower than 1% means the calories are still too high or the treats are not being counted.
Can I just feed less of the normal food?: You can, but the cut is 36%, and it cuts the protein, vitamins and minerals in the bowl by the same 36%. A weight-loss food has more of those per calorie so the dog gets a full ration of everything except energy, and more fibre so the smaller bowl still fills it up. Ask the vet before starting any diet; some dogs have a medical reason for the weight.
What about treats?: Count them inside the 783 kcal: a 10% allowance is 78 kcal a day, which leaves 704 kcal for food, 207 g instead of 230. Set the day's kibble aside in the morning and use pieces of it as treats; a dog does not know the difference, and the total cannot creep.
My dog is hungry all the time. What can I do?: Split the 230 g into three or four meals instead of two, feed from a slow bowl or a puzzle feeder so the meal lasts longer, and add water to the kibble. Plain green beans or zucchini add bulk for almost no calories. Do not add the calories back unless the four-week check says the dog is losing faster than 2% a week.
What do I feed once the dog reaches 25 kg?: The neutered-adult amount for 25 kg, not for 30: 1,062 kcal a day, 312 g of the same 3,400 kcal/kg food or the grams of any other food from the dog food calculator. Weigh the dog monthly for the first three months; if the scale creeps up by a kilogram, go back to the diet amount for a month.

Figures come from the calculators on this site and the published feeding equations (NRC 2006, WSAVA, AAHA). Individual animals vary by up to 30%: adjust by body condition, and ask your vet before changing the diet of a puppy or kitten, a pregnant or nursing animal, or one with an illness.