What is low-fat dog food, and does your dog need it? Low-fat food is a food that carries less fat than a standard adult food — often below about 10% fat on a dry-matter basis, against a published AAFCO minimum of 5.5% fat for an adult dog. Fat is the most calorie-dense part of food, carrying more than twice the calories of protein or carbohydrate per gram, so cutting fat is the fastest way to cut calories — which is why low-fat food is used for weight loss and for dogs that cannot cope with fat, most often after pancreatitis. This guide explains what low fat means, who benefits, who should not have it, and how to read the label.
The short version is: most healthy dogs do not need a low-fat food — a standard complete and balanced food with a moderate fat level is right for them. Low-fat food is worth considering for a dog that needs to lose weight, a dog that has had pancreatitis, or a dog whose vet has advised a low-fat diet for a digestive problem. A growing puppy, a very active dog, or a pregnant or nursing mother should not have a low-fat food without veterinary advice, because they need the calories that fat provides. The dog food calculator works out daily calories for any dog, and the adult dog food calculator guide gives the full calorie tables by weight.
What does low fat mean on a label?
Fat on a label is given as a percentage of the food as sold, and that number is not comparable between a wet food and a dry food, because wet food is mostly water. To compare foods fairly, convert to a dry-matter basis: take the fat percentage, divide it by the dry matter percentage (100 minus the moisture percentage), and multiply by 100. A wet food at 4% fat and 75% moisture is 16% fat on a dry-matter basis, while a dry food at 12% fat and 10% moisture is about 13% — so the wet food carries more fat per mouthful than the dry food, even though its label number is lower. Always compare on a dry-matter basis, and always check the moisture figure on the label.
The published AAFCO minimum for an adult dog is 5.5% fat on a dry-matter basis, and fat is not just calories: it carries the fat-soluble vitamins, it supplies the essential fatty acids a dog cannot make for itself, and it makes food taste good. A food below the minimum is not complete and balanced, and a food far below the minimum for a long time can leave a dog short of essential fatty acids. A food marketed as low fat often carries below about 10% fat on a dry-matter basis — clearly less than a standard food, but still well above the minimum. That is the range to look for: low enough to cut calories, high enough to stay complete and balanced.
Who benefits from low-fat food?
A dog that needs to lose weight benefits most: cutting fat cuts calories fast, because fat carries more than twice the calories of protein or carbohydrate per gram, so a low-fat food lets the dog eat a satisfying amount while taking in fewer calories. A dog that has had pancreatitis benefits too — pancreatitis is an inflamed pancreas, and a fatty meal is the most common trigger for a flare-up, so a vet will usually recommend a low-fat diet for life after pancreatitis. A dog with some digestive problems, where fat is hard to digest, may also do better on a lower-fat food, with veterinary advice.
A dog that is simply fussy, or that has a sensitive stomach without a fat problem, does not necessarily need a low-fat food — a sensitive stomach is usually about a particular protein or a sudden change, not about fat itself, and many dogs with sensitive stomachs do well on a food with a moderate fat level. The best food for dogs with sensitive stomachs guide covers that choice, and the pancreatitis in dogs guide explains the condition and why fat matters after it.
Who should not have low-fat food?
A growing puppy should not have a low-fat food without veterinary advice: a puppy is growing fast and needs a lot of calories per mouthful, and a low-fat food may not provide enough. A very active or working dog should not have one either, for the same reason — a dog that runs or works for hours a day burns a lot of calories, and fat is the easiest way to supply them. A pregnant or nursing mother should not have a low-fat food: she needs more calories than at any other time in her life, and cutting fat then is the wrong direction. A dog that is underweight should not have a low-fat food either — it needs more calories, not fewer.
A dog with a health condition of any kind should have its diet changed only with veterinary advice, and that applies to low-fat food as much as to any other change. If your dog has had pancreatitis, follow your vet's advice on fat level for life, not just for a few weeks — pancreatitis can come back, and a fatty meal is the most common trigger. The feeding a pregnant dog guide and the feeding a nursing dog guide cover the times when extra calories are needed, and the how much food should a puppy eat guide gives the calorie tables for growing dogs.
How to choose a low-fat food
Choose a food labelled complete and balanced, with a named animal protein as the first ingredient, and compare fat on a dry-matter basis — not by the number on the front of the bag. Check the kcal per 100 g too, because a low-fat food can still be high in calories if it is high in carbohydrate, and the calorie density is what matters for weight loss. Feed a measured amount, not a free choice, and weigh the dog monthly so weight does not creep up unnoticed. If the dog has had pancreatitis, ask your vet which fat level to aim for, and stick to it — a 'low-fat' label without a number on it is not enough information.
Change foods gradually over seven days, mixing the old and new in increasing proportions, because a sudden change upsets even a healthy gut — and a dog that has had pancreatitis has a gut that is already sensitive. Give the new food at least four weeks before judging it, and watch the stools: a dog that moves to a lower-fat food may have softer stools for a few days, and if they do not settle, the food may not suit that dog. Keep treats low in fat too — a low-fat food with fatty treats is not a low-fat diet, and a single fatty treat can be enough to trigger a flare-up in a dog that has had pancreatitis. The how to switch dog food safely guide gives the full seven-day plan, and the high-protein dog food guide covers the other end of the protein and fat choice.
Low fat and weight loss
Low-fat food helps weight loss because fat is the most calorie-dense part of food, so cutting fat cuts calories without cutting the amount of food much — and the amount of food matters, because a dog that feels hungry all the time will beg, scavenge, and make its owner's life hard. A low-fat food often also carries more fibre, which adds bulk without calories and helps the dog feel full. That combination — less fat, more fibre — is why a low-fat food is a common choice for weight loss, and why it works better than simply feeding less of a high-fat food, which leaves the dog hungry on a small amount.
But low fat is not the whole answer to weight loss: the amount matters as much as the food, and a dog fed too much of a low-fat food will still gain weight. Measure every gram, keep treats under 10% of daily calories, and weigh the dog monthly. A commonly cited safe target is about 1% of body weight per month for dogs and about half a percent to 1% for cats — slow, steady loss that stays off. The best food for overweight dogs guide explains how a weight-loss food differs from a normal food, and the how many calories to lose weight for dogs guide gives the calorie tables.
For related reading, see the dog food calculator, the adult dog food calculator guide, the high-protein dog food guide, the best food for overweight dogs guide, the pancreatitis in dogs guide, the how to switch dog food safely guide.
Frequently asked questions
What is low-fat dog food?
A food that carries less fat than a standard adult food — often below about 10% fat on a dry-matter basis, against a published AAFCO minimum of 5.5% fat for an adult dog. Compare foods on a dry-matter basis, not by the number on the bag, because wet food is mostly water and its label number looks lower than it really is.
Does my dog need low-fat food?
Most healthy dogs do not — a standard complete and balanced food with a moderate fat level is right for them. Low-fat food is worth considering for a dog that needs to lose weight, a dog that has had pancreatitis, or a dog whose vet has advised a low-fat diet for a digestive problem. Growing puppys, very active dogs, and pregnant or nursing mothers should not have a low-fat food without veterinary advice.
Is low-fat food good after pancreatitis?
Yes — a vet will usually recommend a low-fat diet for life after pancreatitis, because a fatty meal is the most common trigger for a flare-up. Ask your vet which fat level to aim for, keep treats low in fat too, and do not let the dog scavenge fatty food. A single fatty treat can be enough to trigger a flare-up.
How do I compare fat between wet and dry food?
Convert to a dry-matter basis: take the fat percentage, divide it by the dry matter percentage (100 minus the moisture percentage), and multiply by 100. A wet food at 4% fat and 75% moisture is 16% fat on a dry-matter basis, while a dry food at 12% fat and 10% moisture is about 13% — so the wet food carries more fat per mouthful than the dry food.
Will low-fat food help my dog lose weight?
It helps, because fat carries more than twice the calories of protein or carbohydrate per gram, so cutting fat cuts calories without cutting the amount of food much. But the amount matters as much as the food — measure every gram, keep treats under 10% of daily calories, and weigh the dog monthly. Aim for slow, steady loss of about 1% of body weight per month for dogs and about half a percent to 1% for cats.
How do I switch to a low-fat food?
Gradually, over seven days — three quarters old food and one quarter new food for two days, half and half for two days, one quarter old and three quarters new for two days, then all new food. Give the new food at least four weeks before judging it, keep treats low in fat, and weigh the dog monthly.
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.