You would not trust a diet plan for yourself that skipped the actual numbers, so do not trust one for your dog that does either. To help your dog lose weight safely, feed for the weight the dog should be rather than the weight it is, weigh every meal on a gram scale, cap treats at 10 percent of calories, and aim to lose 1 to 2 percent of body weight per week. Faster than that costs muscle; slower is fine as long as the scale keeps moving. This post covers how to tell if your dog is actually overweight, how to set the calorie target, what kind of food makes the diet easier, and how to keep the dog from talking you out of it.
Is your dog actually overweight
Probably, statistically. The Association for Pet Obesity Prevention's 2022 survey classified 59 percent of US dogs as overweight or having obesity: 37 percent overweight and 22 percent with obesity, against 40 percent at an ideal condition.1 Owners are bad at seeing it because a slightly round dog now looks normal at the park.
Use the 9 point body condition score instead of your eye. The WSAVA chart describes a 5 as ribs palpable without excess fat covering, a waist visible behind the ribs from above, and an abdomen that tucks up from the side. A 7 is ribs palpable with difficulty under heavy fat cover, noticeable fat deposits over the lower back and tail base, and a waist absent or barely visible. An 8 is ribs not palpable, or palpable only with significant pressure, with no waist and no tuck.2 Run your hands over your dog right now. If you have to push to find ribs, you are at 7 or above.
Why it matters more than a few extra pounds
Cornell's Riney Canine Health Center puts it plainly: obesity affects nearly every major organ and body system and often leads to shorter lifespans, with joint stress the most common consequence, and it raises anesthesia risk if the dog ever needs surgery.3 The weight is not a cosmetic issue. It is the single most fixable health problem most dogs have.
Set the target: ideal weight, not current weight
Every calorie formula starts with body weight, and if you plug in the current weight of an overweight dog you get a number that maintains the problem. Estimate ideal weight from the body condition score, or ask your vet for a number. Then calculate resting energy: the Merck Veterinary Manual gives it as 70 times ideal weight in kilograms raised to the 0.75 power.4 For a dog whose ideal weight is 50 lb (22.7 kg) that is about 727 kcal. Weight loss diets typically feed at or slightly above that resting number rather than the 1.6 times maintenance multiplier, but your vet should set the exact figure, since VCA notes the calorie target for weight loss is calculated by the veterinary team and adjusted as the dog progresses.5 Our portion guide walks through the full formula and a table by weight.
The safe rate
VCA's weight reduction guidance says dogs should ideally lose between 1 and 2 percent of their starting body weight per week, and that closer to 0.5 percent may be more realistic for severely obese dogs.5 Cornell gives the same 1 to 2 percent range.3 For a 70 lb dog that is roughly 0.7 to 1.4 lb a week. A dog that needs to drop 14 lb is looking at three to five months, and VCA points out the obvious math that losing 1 percent a week takes twice as long as losing 2 percent.5 Plan for the long version. Crash diets lose muscle along with fat, and a dog that loses muscle looks thinner while getting weaker.
Weigh everything
VCA recommends a kitchen gram scale rather than a measuring cup, because cups are not accurate enough for a weight loss plan.5 A heaping cup versus a level cup is a real difference on the same food, and that difference can eat the entire deficit you were trying to create. Weigh the dog every two weeks on the same scale, at the same time of day, and write it down. If the number has not moved in a month, cut the daily food by 10 percent and try again.
Treats: the 10 percent rule, enforced
The WSAVA treat guide says "Treats should always make up less than 10% of a dog's daily calorie intake," and VCA's weight reduction plan uses the same rule, 10 percent from treats and 90 percent from food.6 For the 727 kcal dog above that is about 70 kcal a day, which is a small handful of freeze dried liver or a couple of commercial biscuits, and it comes out of the food budget, not on top of it. The dog does not know a treat is small. Break them into pieces and count the pieces. Our single ingredient treats guide covers low calorie options that still feel like a reward.
What kind of food helps
Cornell describes weight loss diets as lower in calories per cup, higher in fiber, and lower in fat, and suggests a density of around 300 calories per cup as a reasonable target.3 The logic is volume: a dog on a diet still wants a full bowl, and a food with fewer calories per cup lets you give one. Two practical routes get you there:
- A lower calorie kibble with real protein. Check the kcal per cup on the bag and compare across brands. Some "weight management" formulas cut calories by adding fiber and cutting protein at the same time; look for one that keeps protein near the top of the ingredient list so the dog holds muscle while losing fat. Our label reading guide covers how to spot the difference.
- Adding water and volume. Rehydrated food or a spoon of plain canned pumpkin adds bulk with few calories. It does not change the math, but it changes how the dog feels about the math.
Freeze dried raw can work for a dieting dog, but it is calorie dense, so the dry portion looks tiny and the temptation to add "a little more" is constant. If you feed it, weigh it, and rehydrate fully so the bowl looks like a meal. Everything in the dog food collection has passed The Truva Standard, which tells you about the label and the brand, not calories; you still have to read the kcal line.
Exercise helps, but food does the work
More walking is good for joints, mood, and the owner, and it should be part of the plan. It will not by itself fix a dog that is eating 30 percent over its needs. If your dog is stiff or reluctant to move, start with short, frequent walks on soft ground and build slowly. Swimming is excellent for heavy dogs with sore joints if you have access to safe water.
Keeping the dog on your side
A dog on a diet will lobby. Feed at fixed times, split the daily amount into two or three meals so the gaps are shorter, and use a slow feeder or a snuffle mat to stretch the meal out. Move the family onto one rule: nobody feeds from the table, and every treat gets counted. Most failed diets fail in the kitchen with the person who cannot say no, not on the walk.
When to call the vet
Call before you start if your dog is more than a couple of body condition points over, since a vet can confirm the target weight and rule out thyroid or other conditions that cause weight gain. Call if your dog is losing faster than 2 percent a week, loses appetite, or seems weak. Call if two months of honest measuring has moved nothing, because the plan needs adjusting and there may be a medical reason.
Sources
- Association for Pet Obesity Prevention, "2022 State of U.S. Pet Obesity Report," 2022. petobesityprevention.org
- WSAVA Global Nutrition Committee, "Body Condition Score chart, dogs," 2025. wsava.org
- Cornell University Riney Canine Health Center, "Obesity and weight loss in dogs." vet.cornell.edu
- Merck Veterinary Manual, "Nutritional Requirements and Related Diseases of Small Animals." merckvetmanual.com
- VCA Animal Hospitals, "Creating a Weight Reduction Plan for Dogs." vcahospitals.com
- WSAVA Global Nutrition Committee, "Feeding treats to your dog," 2025. wsava.org