What is the best food for overweight dogs? An overweight dog does not need a different kind of food — it needs fewer calories, in a food that keeps it full and holds its muscle while the weight comes off. This guide covers how a weight-loss food differs from a normal food, how many calories an overweight dog should eat, how fast weight should come off, and the mistakes that make weight loss fail. Every figure is an estimate, and a dog that needs to lose a lot of weight should have a plan set with its vet, because a crash diet is dangerous — especially for cats, where rapid weight loss can cause a serious liver problem.
The short version is: feed a complete and balanced food made for weight loss, or feed less of the normal food with your vet's agreement, measure every gram, keep treats under 10% of daily calories, and aim for slow, steady loss — about 1% of body weight per month. Weigh the dog monthly, and if weight is not moving after a month, cut food by about 10% and re-weigh in another month. A dog that loses weight slowly and keeps it off is a success; a dog that loses weight fast and puts it straight back on is not. The dog ideal weight calculator works out a target weight range, and the how to help a dog lose weight safely guide gives the full plan.
How does a weight-loss food differ from a normal food?
A weight-loss food is a normal complete and balanced food with fewer calories per mouthful. It usually does that in three ways: less fat, more fibre, and more protein. Less fat matters because fat carries more than twice the calories of protein or carbohydrate per gram, so cutting fat cuts calories fast. More fibre matters because fibre adds bulk without calories, so the dog feels full on fewer calories — a dog that feels hungry all the time will beg, scavenge, and make its owner's life hard, so fullness is not a luxury, it is part of the plan. More protein matters because a dog losing weight loses muscle as well as fat unless its protein intake stays good, and muscle is what keeps it moving and keeps its metabolism up.
Some weight-loss foods also add ingredients that help the dog feel full or support joint health, but those are extras, not the core of it. The core is the calorie density on the label: check the kcal per 100 g or per cup, and compare it with the normal food. A weight-loss food should carry clearly fewer calories per 100 g than the normal food from the same maker — if it does not, it is not doing the job. Do not choose a food by the picture on the bag or by the word 'light' alone: 'light' is a marketing word, and the only number that matters is the kcal per 100 g. The dog food calculator and the cat food calculator convert calories into cups and grams for any food.
How many calories should an overweight dog eat?
Start with the resting energy requirement, or RER — the calories a dog burns at rest. The formula vets use is: RER equals 70 times body weight in kg to the power of 0.75. A typical neutered adult dog needs about 1.6 times its RER, and an overweight dog that needs to lose weight usually needs about 1.1 times its RER as a starting point — less than maintenance, but not a crash diet. The table below gives the daily calories for an overweight dog at different weights, at the normal adult factor, at the weight-loss target, and at a gentler senior factor. Use the row nearest the dog's current weight, then adjust by monthly weigh-ins.
| Body weight | Normal adult calories | Weight-loss calories (target) | Senior / gentle loss |
|---|---|---|---|
| 5 kg | 375 | 255 | 305 |
| 10 kg | 630 | 435 | 510 |
| 20 kg | 1060 | 730 | 860 |
| 30 kg | 1435 | 985 | 1165 |
| 40 kg | 1780 | 1225 | 1445 |
If weight is not moving after a month, cut food by about 10% and re-weigh in another month. If weight is falling faster than about 1% of body weight per month, feed a little more — fast weight loss in a dog loses muscle as well as fat, and in cats it can cause a serious liver problem, so slow is safe. Note that calories are the real target and cups are only a translation: different foods have very different calorie densities, so always check the kcal per cup or per 100 g on your own bag or tin and work from that. The dog calorie calculator works out the same figures for any weight, and the how many calories to lose weight for dogs guide gives the full tables.
How fast should an overweight dog lose weight?
Slowly. A commonly cited safe target is about 1% of body weight per month, which means a 20 kg dog losing about 200 g a month and a 5 kg cat losing about 25 to 50 g a month. That sounds slow, and it is — but slow weight loss is the kind that stays off, because it gives the dog time to adjust, keeps muscle, and does not leave the dog hungry and miserable. A dog that loses weight faster than that is losing muscle as well as fat, and a cat that loses weight fast can develop a serious liver problem called hepatic lipidosis, which is a veterinary emergency. If your dog is losing weight faster than the target, feed a little more and mention it to your vet.
Weigh the dog monthly, at the same time of day, on the same scales, and write the number down — the line over months is what matters, not any single reading. Feel the ribs at every weigh-in too: you should be able to feel them easily under a thin layer of fat, and see a waist from above and from the side. A dog that is losing weight but still has no waist is still overweight, and a dog whose ribs are easy to see and whose waist is very obvious may have gone too far. The how to weigh your dog at home guide explains the bathroom-scale method, and the dog body condition score chart and cat body condition score chart show the nine-point scale vets use.
Feeding routine for an overweight dog
Split the daily amount into two meals a day for an adult dog — morning and evening — rather than one large meal, because two smaller meals are easier on digestion and keep the dog feeling fed through the day. Measure food with scales or a measuring cup, not a mug or a handful: a mug of dry food can carry a quarter more calories than a measured cup, and that quarter is often the whole difference between losing weight and not losing it. Feed in a quiet place, at the same times every day, and take the bowl away after twenty minutes so the dog learns that food comes at meal times, not all day.
Keep treats under 10% of daily calories, and count them. A treat here, a piece of cheese there, and a biscuit for being good can add a quarter to the dog's daily calories without anyone noticing — and that quarter is often the whole weight-loss plan, undone. Use the dog's own food as treats, or a single low-calorie treat, and stop giving food from the table. If there are children in the house, agree together who feeds the dog and what treats are allowed, because a dog fed by three people is fed three times. The free feeding vs scheduled feeding for dogs guide explains why leaving food down all day makes weight loss almost impossible.
Mistakes that make weight loss fail
The most common mistake is guessing the amount: a dog fed by eye is almost always fed too much, because a mug or a handful is not a measure. The second is forgetting treats: treats, table scraps, and food from other pets' bowls all count, and they often add up to more than the meal itself. The third is changing food every few weeks: a weight-loss plan needs at least two months before it can be judged, and a food changed after two weeks has not had a fair trial. The fourth is cutting food too fast: a crash diet loses muscle, leaves the dog hungry and miserable, and in cats can cause a serious liver problem. The fifth is giving up after a plateau: weight loss is rarely a straight line, and a month with no change is normal — cut food by about 10% and keep going, rather than abandoning the plan.
The sixth mistake is forgetting exercise: food is most of weight loss, but exercise matters too, because it keeps muscle, burns calories, and keeps the dog happy. An overweight dog should build exercise up gradually — short, frequent walks or play sessions rather than one long weekend hike, because a heavy dog that is suddenly asked to run will strain its joints. The best exercise for overweight dogs guide gives a safe build-up plan, and the dog weight loss diet plan guide puts food and exercise together into a week-by-week plan.
For related reading, see the how to help a dog lose weight safely guide, the dog weight loss diet plan guide, the how many calories to lose weight for dogs guide, the dog ideal weight calculator, the best exercise for overweight dogs guide, the free feeding vs scheduled feeding for dogs guide.
Frequently asked questions
What is the best food for an overweight dog?
A complete and balanced food made for weight loss — fewer calories per mouthful, less fat, more fibre so the dog feels full, and enough protein to hold muscle while weight comes off. Check the kcal per 100 g on the label rather than the word 'light' on the bag, feed a measured amount, keep treats under 10% of daily calories, and weigh the dog monthly.
How many calories should an overweight dog eat?
As a starting point, about 1.1 times its resting energy requirement (RER), which is 70 times body weight in kg to the power of 0.75. A dog of 10 kg needs about 435 calories a day to lose weight, against about 630 at normal maintenance. Adjust by monthly weigh-ins, and ask your vet to set the target for a dog that needs to lose a lot of weight.
How fast should an overweight dog lose weight?
A commonly cited safe target is about 1% of body weight per month. That sounds slow, and it is — but slow weight loss is the kind that stays off, and fast weight loss loses muscle as well as fat. In cats, rapid weight loss can cause a serious liver problem, so slow is especially important for cats. If your dog is losing weight faster than the target, feed a little more and mention it to your vet.
Can I just feed less of the normal food?
Yes, with your vet's agreement — feeding less of a normal complete and balanced food works, as long as the amount is measured and the dog is weighed monthly. A food made for weight loss has the advantage of more fibre and protein per calorie, so the dog feels fuller and holds muscle better, but a measured smaller portion of normal food is a fair alternative for a dog that only needs to lose a little.
Do treats count in a weight-loss plan?
Yes — treats, table scraps, and food from other pets' bowls all count, and they often add up to more than the meal itself. Keep treats under 10% of daily calories, use the dog's own food as treats or a single low-calorie treat, and agree in the household who feeds the dog so it is not fed three times by three people.
When should an overweight dog see a vet?
Before starting a weight-loss plan if the dog needs to lose a lot of weight, if it has a health condition, or if it is a senior — and promptly if it is losing weight faster than the target, if it stops eating, or if it is lethargic. A vet check first is sensible because some medical conditions cause weight gain, and those need treating, not just less food.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.