Dog Weight Loss Planner
Plan a safe rate of weight loss for an overweight dog, with a daily calorie target and a realistic week-by-week timeline.
From the ideal weight estimator, or agreed with your vet.
Faster than 2% a week risks muscle loss rather than fat loss.
Feed per day to reach target
662 kcal per day
- Weight to lose
- 5.0 kg
- Expected loss per week
- 0.3 kg
- Time to target
- 23 weeks (about 5.3 months)
| Week | Expected weight |
|---|---|
| Start | 25.0 kg |
| Week 4 | 24.0 kg |
| Week 8 | 23.1 kg |
| Week 12 | 22.2 kg |
| Week 16 | 21.3 kg |
| Week 20 | 20.4 kg |
| Week 23 | 20.0 kg |
This calorie figure is the resting requirement at the target weight. It is a genuine restriction, and dogs on it are hungry. Do not go below it without veterinary supervision, and stop if weight falls faster than 2% a week.
How this is calculated
Calories are set from the resting energy requirement of the target weight, which is the standard veterinary starting point for weight loss. Progress is modelled as a percentage of current body weight per week, so it slows as the dog gets lighter, which is what actually happens.
daily calories = 70 × (target weight in kg)^0.75
each week: new weight = current − (current × weekly rate) Worked example
A 25 kg dog with a 20 kg target: daily calories = 70 × 200.75 = 662 kcal. At 1% a week the first week's loss is 250 g, falling to about 205 g a week near the target. Total time is roughly 23 weeks, or five months.
Why loss slows down
A percentage of a shrinking number gets smaller. This is not a plateau or a failure; it is arithmetic, and it is worth knowing in advance so a slowing rate near the end does not look like the diet has stopped working.
Sources
- American Animal Hospital Association. 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats.
- WSAVA Global Nutrition Committee. Global Nutrition Guidelines and toolkit.
- Kealy RD, Lawler DF, Ballam JM, Mantz SL, Biery DN, Greeley EH, Lust G, Segre M, Smith GK, Stowe HD. Effects of diet restriction on life span and age-related changes in dogs. J Am Vet Med Assoc. 2002;220(9):1315–1320. The Labrador lifespan study: lean-fed dogs lived a median 1.8 years longer.
Do this with your vet
A restriction of this size should be supervised, for three reasons. Some causes of weight gain are medical, and hypothyroidism in particular will defeat any diet. Reducing an ordinary complete food by a third can push essential nutrients below requirement, which is why purpose-built weight-loss diets exist. And a monthly weigh-in on the practice scales is far more reliable than a bathroom scale at home.
What makes it work
Weigh the food. Every study of owner-measured portions finds large errors when scoops are used, and a 20% overshoot cancels the entire deficit. Weigh the dog monthly, always on the same scales, and record it. Count everything that goes in the dog's mouth against the daily total, including chews, dental sticks and training rewards.
Tell everyone in the household the same number. The most common reason a carefully calculated diet fails is that two people are each feeding the dog, and both assume the other has not.
Common questions
How fast should a dog lose weight?
One percent of body weight a week is the standard target, with 2% the maximum. Faster than that and the dog loses muscle alongside fat, and the weight comes back. A 25 kg dog losing to 20 kg should take roughly five months.
How many calories should an overweight dog eat?
Start at the resting energy requirement of the target weight: 70 × (target kg)^0.75. For a target of 20 kg that is 662 kcal a day. This is a real restriction, and it is deliberately below what the dog needs to maintain its current weight.
Why feed for the target weight rather than the current weight?
Feeding for current weight maintains current weight. That is the whole point. Feeding the resting requirement of the goal weight creates the deficit that produces loss, while still supplying enough for basic function.
My dog is always hungry on a diet. What can I do?
Split the ration into three or four meals, bulk it out with green beans, courgette or plain canned pumpkin, use a slow-feeder bowl or a puzzle feeder, and move treats to vegetables. A prescription weight-loss food is designed for exactly this: high fiber and protein, low calorie density, so the dog eats a normal-looking volume.
My dog has stopped losing weight. Why?
Almost always uncounted calories: treats, chews, table scraps, another household member feeding, or a neighbor. Track everything for a week before cutting the ration further. If the food is genuinely controlled and loss has stalled, ask your vet about hypothyroidism.
Should I just exercise my dog more instead?
Exercise helps preserve muscle and is worth doing, but weight loss is driven by intake. A 30 minute walk burns roughly 60 to 100 kcal for a medium dog, which is about one and a half biscuits. Diet does the work; exercise protects the muscle.