Every part of the dog food industry has something to sell you about what to feed. Almost nothing is sold about how much, and the amount is the part with actual evidence behind it.
Here is that evidence in one sentence, before anything else. In the only lifelong controlled feeding trial ever run in dogs, the ones kept lean lived 1.8 years longer than their own littermates, and the age at which hip arthritis first showed up moved from six years old to twelve.
Nothing in any bag has ever been shown to do that. It costs nothing, which is precisely why you have never seen it advertised.
This article is how to work out the number, why the number on the bag runs high, and the hands-on test that beats the arithmetic every time.
The short answer
There is a formula, and it is worth doing once so you know roughly where you are:
Resting calories = 70 × (body weight in kilograms) to the power of 0.75 Then multiply: × 1.6 for a typical neutered adult dog, × 1.8 if intact, × 1.4 if she gains weight easily.
For a 65 lb dog that works out to about 1,150 calories a day.
And now the caveat that the Merck Veterinary Manual attaches to it, which matters more than the formula:
“Any given animal may require as much as 30% more or less of the calories calculated for its body weight than another animal with the same body weight.”
Thirty percent in either direction. Two identical-looking dogs of the same weight can genuinely need 800 calories and 1,500 calories. So the formula is a starting point and nothing more — the thing that settles it is your hands on the dog’s ribs, checked every couple of weeks.
If you would rather not do the arithmetic, the feeding calculator does it, including the thirty percent band and what it works out to in cups and cost.
How much should I feed my dog?
Start from resting calories — 70 × (weight in kg)^0.75 — then multiply by about 1.6 for a typical neutered adult, 1.8 if intact, or 1.4 if your dog gains weight easily. A 65 lb dog lands near 1,150 calories a day. Treat that as a starting point only: the same-weight requirement varies by up to 30 percent between individual dogs, so adjust based on body condition over the following weeks.
Why the number on the bag runs high
Most people skip the arithmetic and use the feeding chart on the package. That is reasonable, and it is also the single most common reason dogs are overfed.
Lisa Freeman, a board-certified veterinary nutritionist at Tufts, went through the feeding directions on eight dry adult dog foods. Her finding: “four of the diets recommended appropriate calorie intake for dogs of small or medium sizes but recommended excessive calories for larger dogs.” One food recommended up to 61 percent more calories than the dog needed.
Sixty-one percent. On a 1,150-calorie dog, that is an extra 700 calories a day, every day.
Her conclusion is the useful part: “feeding directions are only a starting point.”
And the manufacturers agree, in writing. AAFCO’s own consumer language says: “Always remember, feeding directions are guidelines that may need modification to meet a particular pet’s needs.” The American Animal Hospital Association adds the part that explains why they vary so much between brands — AAFCO does not standardize how those directions are calculated. Every company works them out its own way.
Being honest about the limits of this: that Tufts analysis is a veterinary nutritionist’s review of eight products, not a peer-reviewed study, and as far as we can find no peer-reviewed head-to-head study comparing dog food label directions against measured requirements exists. One has been done in cat food. Not in dogs. So the fair statement is that the best available evidence says label directions skew high, particularly for large dogs, and that nobody has measured it rigorously. That gap is itself worth knowing about.
There is a second, quieter reason the numbers drift high. The calorie figure on a bag is often calculated rather than measured, and the calculation uses crude fiber — which understates true dietary fiber by about half. That inflates the calculated calories by roughly five percent, which is about fifty-seven calories a day of invisible overfeeding in a medium dog. Not a catastrophe on its own. It compounds over a decade.
Are the feeding instructions on the bag accurate?
They are a starting point, and they tend to run high — especially for large dogs. A Tufts veterinary nutritionist reviewing eight dry foods found several recommended excessive calories for bigger dogs, one by up to 61 percent. AAFCO’s own guidance calls feeding directions “guidelines that may need modification,” and AAHA notes AAFCO does not standardize how they are calculated. Use them to start, then adjust to your dog.
Cups, scoops and the thing to fix first
Whatever number you land on, it arrives in the bowl through a measuring cup — and that is where a careful plan quietly falls apart.
A “cup” of kibble is a volume, not a weight, and how much food fills it depends on kibble size, shape and density. Scooping straight from the bag compacts it. Different foods differ substantially per cup. None of that shows up when you look at the bowl.
Weigh the food instead. A twelve-dollar kitchen scale removes the entire problem, permanently. Weigh once to learn what your dog’s portion looks like, and after that the cup is at least consistent.
This matters because owners are not good at estimating any of it, and that is measured. In a study of 174 dog owners:
- 51 percent scored their dog’s body condition correctly
- 38 percent underestimated it — they thought their dog was leaner than it was
- only 48 percent estimated their dog’s weight within 10 percent
- only 49 percent interpreted a wet food label correctly, and 44 percent a dry food label
Read the direction of that error. When owners are wrong about body condition, they are wrong toward “she’s fine.” Nobody looks at a slightly heavy dog and sees a fat one.
Body condition: the answer the formula cannot give you
This is the part that actually decides how much to feed. The WSAVA nine-point body condition chart is free, takes thirty seconds, and needs no equipment.
The middle of the scale, in WSAVA’s own words:
| Score | What it feels and looks like |
|---|---|
| 4 / 9 | “Ribs easily palpable, with minimal fat covering. Waist easily noted, viewed from above. Abdominal tuck evident.” |
| 5 / 9 | “Ribs palpable without excess fat covering. Waist observed behind ribs when viewed from above. Abdomen tucked up when viewed from side.” |
| 6 / 9 | “Ribs palpable with slight excess fat covering. Waist is discernible viewed from above but is not prominent.” |
| 7 / 9 | “Ribs palpable with difficulty; heavy fat cover.” |
How to actually do it. Run both thumbs along your dog’s ribs with light pressure, the way you would feel the back of your own hand. You are looking for ribs that are easy to find without pressing. Then look down at her from above for a waist behind the ribs, and from the side for the tuck up toward the hind legs.
Do it every two weeks, at the same time of day, and write the score down. A single score tells you where you are; a series tells you whether what you are doing is working. That is the whole feedback loop, and it is the only one that matters.
If she is drifting up, cut the daily amount by about ten percent and reassess in a month. If she is dropping when you do not want her to, add ten percent. Slowly, in both directions.
How do I know if my dog is overweight?
Use your hands, not the scale. At an ideal score of 4 or 5 out of 9, ribs are easy to feel with light pressure, there is a visible waist behind the ribs when you look down from above, and the belly tucks up when viewed from the side. At 6 you can feel ribs through a layer of fat and the waist is faint. At 7 the ribs are hard to find. Roughly half to sixty percent of dogs are assessed as overweight by veterinarians, so it is worth checking rather than assuming.
Muscle condition is a separate score, and for a working dog it matters more
This is the part almost nobody is told, and it changes how you read everything above.
Muscle condition is scored separately from body condition, by feeling over the spine, hips, shoulders and skull for muscle loss. It is graded simply: normal, or mild, moderate or severe atrophy.
The reason it is separate is this, from Valerie Parker, a board-certified veterinary internist: “You can have an obese animal with moderate or severe muscle loss.”
Sit with that. Fat and muscle move independently. A dog can be carrying too much weight and losing the muscle she needs to work, at the same time — and the fat hides it, because she still looks substantial.
For a service dog this is not a cosmetic issue. Muscle is what braces, what climbs stairs, what gets a dog up off a floor at eleven years old. A dog who is heavy and under-muscled is carrying more load on less structure, which is the worst combination for joints already doing a job. We went through what that end of a working life looks like in retiring a service dog.
Check both. Every time.
The finding that should decide this for you
Now the evidence that makes the rest of this article worth acting on.
Forty-eight Labrador Retrievers were followed from eight weeks old until death, in littermate pairs. One of each pair was fed twenty-five percent less than its sibling. Same food, same kennel, same everything else. The results were published across two decades:
“Major lifetime observations included 1·8 years longer median lifespan among diet-restricted dogs, with delayed onset of late life diseases, especially osteoarthritis. Long-term DR did not negatively affect skeletal maturation, structure or metabolism.”
Median lifespan 13.0 years against 11.2. About fifteen percent more life.
And the joints:
“Median age at first identification of radiographic evidence of hip joint osteoarthritis was significantly lower in the control-fed group (6 years), compared with the restricted-fed group (12 years).”
| Age | Hip arthritis, control-fed | Hip arthritis, lean-fed |
|---|---|---|
| 2 years | 25% | 4% |
| 5 years | 39% | 13% |
| 8 years | 64% | 14% |
| 14 years | 83% | 50% |
At eight years old: 64 percent against 14 percent. Same breed, same lines, same kennel. The only difference was how much went in the bowl.
The two things you must know about that study
First, “restricted” is a misleading word. The restricted dogs sat at a body condition score of 4.6 out of 9. The control dogs sat at 6.7. The lean group was at a normal, healthy weight. The control group was overweight — which is to say, the control group was the ordinary dog in the ordinary home. This is a study of leanness, not of deprivation. Nobody was going hungry.
Second, disclose the funding. The trial was conducted and funded by Nestlé Purina. It was forty-eight dogs, of one breed, at one kennel, on one diet. That is a real limitation and we are not going to skip it just because we like the result. What supports it is that the population data points the same way: across 50,787 neutered dogs in twelve breeds, overweight dogs had shorter median lifespans in every breed studied — two and a half years in Yorkshire Terriers, around six months in Labradors. That study can only show association. The littermate trial supplies the causal arm.
Why this is different for a working dog
For a pet, hip arthritis at six versus twelve is a welfare question. For a service dog it is a career.
A dog who develops significant hip arthritis at six is retiring at seven. A dog who develops it at twelve may work until eleven. That is the difference between one dog and two — two years of training, two placements, and, for an owner-trainer, doing the whole thing again from a puppy while the first dog is still alive and still needs care.
There is no supplement, no premium formula and no ingredient that has ever been shown to do that. The intervention is free, and it is the amount.
Does a working dog need more food?
Usually less than people assume, and this is where “working dog” marketing does real damage.
Actual work costs about 1.1 calories per kilogram of body weight per kilometer traveled. The published activity bands put agility, flyball and racing in the lowest tier — under a 25 percent increase over maintenance. Field trials and hunting sit in the middle. Only sled racing and long-distance carting exceed double maintenance.
A mobility or psychiatric service dog doing house, errands and appointments is nowhere near any of those. Energetically she is an adult pet dog. Skilled work and endurance work are different things, and only one of them is a calorie problem. There is no AAFCO working dog nutrient profile for a “performance” food to meet either — the pillar article goes through why that gap exists.
The comparison that makes the point sharpest: a study of sports dogs against pet dogs found median body condition scores of 5 versus 6, and that 78 percent of the pet dogs were classified as too heavy, against 45 percent of the sports dogs. Pet dog owners fed approximately sixty percent more per day.
The dogs doing more work were eating less, and were in better condition.
Does a service dog need more food than a pet dog?
Generally no. A mobility or psychiatric service dog’s daily workload is energetically similar to an active pet dog’s. Real increases in requirement start with sustained endurance work — sledding, long-distance carting — not with task work through a normal day. Feed to body condition rather than to job title, and treat any bag marketed as a “performance” or “working” formula as an ordinary adult food, because legally that is what it is.
Where the number genuinely changes
Older dogs need more protein, not less. The old advice to restrict protein in seniors is out of date. The National Academies’ own consumer publication states that older dogs “appear to require somewhat more protein to maintain their protein reserves, perhaps as much as 50% more,” while needing about twenty percent fewer total calories.
Fewer calories and more protein means a higher protein density — not a bag with “senior” on the front, which is a marketing word with no AAFCO profile behind it.
Puppies need substantially more, roughly three times resting calories under four months and twice resting after that, dropping toward adult levels as growth finishes.
But if you are raising a large-breed puppy — anything that will mature over 70 pounds — do not use this article as your guide. Growth rate and calcium intake in large-breed puppies are a genuinely high-stakes subject with permanent consequences, and it deserves its own treatment rather than a paragraph. Talk to your veterinarian, and look for the AAFCO growth statement that explicitly covers “growth of large size dogs (70 lb or more as an adult)” — which is explained in how to read a dog food label.
Should I feed my senior dog less protein?
No. That advice is outdated. The National Academies states that older dogs may need “as much as 50% more” protein to maintain their protein reserves, while needing around 20 percent fewer total calories because of reduced activity and a slower metabolism. That means a higher protein density in fewer calories, not a reduction. Muscle loss in an older working dog is the thing to guard against.
How much should I feed a puppy?
Roughly three times resting calories under four months, and about twice resting after that, tapering toward adult levels as growth completes. Large-breed puppies are a separate and higher-stakes question — growth rate and calcium intake affect permanent skeletal development in dogs who will mature over 70 pounds. Use a food whose AAFCO statement explicitly covers large-size growth, and work it out with your veterinarian rather than from a chart.
Nobody sells leanness
Here is the part worth naming plainly.
There is an entire industry built around what goes in the bowl. Premium tiers, ancestral formulas, fresh subscriptions at six to fifteen dollars a day, supplements, boosters, toppers. Some of it is fine. Almost none of it has evidence behind it approaching the strength of the finding above.
And the one intervention that does have that evidence — keeping the dog lean — has no product attached, no margin, and no advertising budget. There is no company whose revenue improves when you feed less. That is not a conspiracy; it is just how attention gets allocated. It does mean that the most valuable thing you can do for your dog is the thing you are least likely to be told.
If you are disabled and on a fixed income and have been made to feel that you are letting your dog down by buying the cheaper bag — the evidence says the amount in the bowl matters more than the price on it. Feed a complete and balanced food you can afford, and feed the right amount of it. That is not a consolation prize. It is the intervention with the best evidence in the entire subject.
What to do this week
- Work out the starting number. Formula above, or the calculator.
- Weigh a portion once on a kitchen scale so you know what it actually looks like.
- Score her body condition today on the nine-point scale, and write it down with the date.
- Score her muscle condition too — spine, hips, shoulders, skull.
- Count the treats. They are food. If treats are more than about ten percent of the day’s calories, take that off the meals.
- Reassess in two weeks. Adjust by ten percent in whichever direction the dog is telling you, and only ten.
- Take the numbers to your next vet appointment. A written series is far more useful to your vet than a guess.
None of this is veterinary advice, and weight loss in particular is a clinical matter — sudden loss or gain that you did not cause needs a veterinarian, not a smaller scoop. If your dog has a diagnosed condition, is pregnant or nursing, is recovering from surgery, or is a large-breed puppy still growing, the plan should be made with your vet.
If we ever review a food we bought, this is one of the seven questions it gets measured against — what it actually did to the dog’s condition over a real trial, not what the bag claimed. You can read how we review things, including what we spend and what we refuse.