Health and Fitness

How to Feed a Dog to Lose Weight


Every other dog, and then some, in the United States is overweight according to the Association for Pet Obesity Prevention (APOP). That means that there are around 44 million overweight or, worse, obese dogs in this country. These dogs need help and that help needs to come from their family in the form of a methodical portion control schedule that uses daily calories as a guide.

One of the challenges with feeding a dog to lose weight is that it requires time, a lot of time, to implement a safe weight loss regimen. Simply cutting back on the dog’s kibble for a week or two will suffice. How much time will it take for an overweight dog to reach their target weight? A numerical example can help to illustrate.

Assume that we have a normally active 52 lb. dog that is about 10 lbs. overweight. This dog is very overweight, almost 20% overweight, although not yet obese. This dog would burn about 1,150 calories each day at 52 lbs. At its target weight of 42 lbs., the dog would burn about 1,000 calories per day. To feed a dog for weight loss, a common guideline is to feed about 75% of the calories that the dog would burn at its target weight until the dog reaches its goal. In our example, that means feeding the dog 75% of 1,000 or 750 calories per day. This works out to be an initial calorie deficit of about 425 calories on the first day of the new ‘diet’. As the dog loses weight over time, the calorie deficit will slowly shrink as the dog is losing weight and their daily calorie needs are slowly shrinking as well.

The graph below depicts the theoretical weight of our 52 lb. dog who is fed 750 calories per day.

dog weight loss feeding

You will notice a few things from this chart. First of all, it will take 106 days for this dog to lose 10 lbs., even on a diet that is rather calorie restrictive. Second, the speed of weight loss is not consistent, even in a theoretical world. The rate of weight loss will change (slow) over time as evidenced by the fact that the line is not straight but slightly curved. In reality, the rate of weight loss is even more non-linear due to a multiple of factors (including owner’s compliance or lack thereof, to the diet program). The graph below shows a more realistic scenario, where the weight loss, while steady over the 106 days, is variable day to day. Those of us who have tried to lose weight ourselves can appreciate this.

actual dog weight loss

The lesson from this analysis is that pet parents with overweight pets need to adjust their expectations when it comes to their pet’s weight loss. Reaching the dog’s target weight will not happen overnight, and will require weeks and weeks of diligence. Obviously, the more overweight (in percentage terms) the pet is, the longer it will take to safely reach their goal. For reference, the table below shows the time it will take for a dog to lose one single pound of body weight while being fed a different daily calorie deficit scenarios.

Daily Calorie Deficit Days to lose 1 lb.
50 70
100 35
150 23
200 18

Lastly, be aware that weight is proportional so a small dog, say 12 lbs. would only need to be 2 lbs. overweight to be as ‘fat’ as in our example. This smaller dog will also need many weeks of dieting in order to lose those 2 lbs.

Steve Pelletier
Steve Pelletier VP, Food

Steve is an advocate for healthy pet food offerings.