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Is My Dog Obese? Should I Put Him On a Doggie Diet?

Obesity among our dog population is estimated at 40%-50%. Many pet owners will show their affection through excess food, table scraps and treats. We obviously love our furry friends and this statistic shows just how much. This, however, is not an appropriate outlet because just like in humans, obesity predisposes dogs to arthritis, diabetes, a variety of respiratory issues, decreased quality of life, and even a shortened lifespan. Our pets rely on us to regulate their caloric intake as the vast majority of dogs will not self-regulate their weight. As such, we strongly recommend a twice daily feeding routine over a free-choice feeding method. This not only allows better control over caloric intake but it also establishes a set routine which most dogs prefer.

To answer this question, veterinarians use a system called a Body Condition Score or BCS. This approach grades your dog on a scale of either 1-5 or 1-9. Using this system takes the differences in breed, skeletal or “frame” size and other factors out of the equation. For example, if you tell me that you have a German Shepard weighing approximately 100 pounds, I cannot tell by that alone if the pet is overweight. A full grown male Shepard may very well reach 100 pounds and still have a perfect body condition score (5/9), while a female with a much smaller frame would most likely be severely overweight at 100 pounds. This grading system gives us a more objective assessment of a pet’s weight. Personally, I prefer the 1-9 scale as I feel that it is more accurate and specific (1 being emaciated, 3 is ideal, 5 being morbidly obese). You can do this assessment at home using the following specific guidelines, Also, next time you’re at the vet ask them to BCS you pet and see how you did!

How much food does my dog need?

The answer to this question may not be as simple as you may think. Just like humans, each individual pet is going to have different caloric requirements based on breed, size, activity level, spay/neuter status, and weight management goals (lose, maintain, gain). To make things even more complicated each individual dog food will vary in its caloric density. Most dog food companies do not include the number of Calories per cup of kibble on the actual bag of food, but this information can be food relatively easily online by a quick google search. Calculating the exact amount of cups of kibble your dog will need per day is done by two simple equations, known as the resting energy requirement or RER and the maintenance energy requirement or MER. Below is a detailed definition of each term, the equations themselves, and an example calculation.

The resting energy requirement (RER) is the BASE energy in calories that your pet needs to maintain his or her current weight based ONLY on what he or she needs to maintain normal physiologic processes and not taking into account any factors such as exercise, current BCS, or any other metabolic differences

The maintenance energy requirement (MER) is basically just the RER adjusted to account for any factors that will affect your dog’s metabolism. For example, a puppy will have an MER of 3 times his or her RER because of the caloric requirements for growth. On the other hand, an obese dog will have an MER of 80% of his or her RER, in order to induce weight loss.

Weight in pounds (lbs) / 2.2 = Weight in kilograms (kg)

RER=30 (Weight kg) + 70


weight loss= RER x 0.8

Puppy (wean to 4 months)=RER x 3

Puppy ( 4months to adult)=RER x 2

neutered/spayed adult=RER x 1.6

intact adult=RER x 1.8

working dog (light to heavy)= RER x 3 to 4

MER X Energy Density of food = (Cal/day) (Cal/Cup of food)

***The energy density will vary greatly based your choice of food. This value will not be on the bag but can be found with a quick internet search.

dog sloganFood Groups


The energy content in dog food just like our food is measured in Calories (also referred to as kcal). This value varies greatly based on the brand and formulation (I.e. Puppy) of your pet’s diet. This topic is covered in detail under the weight management section of this website including instructions for calculating your pet’s exact daily caloric needs.


Complex carbohydrates or starches are molecules that provide energy in the form of glucose, which is an absolute requirement for proper brain and nervous tissue function. Thus, having carbohydrate in your pet’s diet is extremely important. Carbohydrates also contribute to overall health by providing the building blocks for substances like Vitamin C and nonessential amino acids.

SOURCES: Grains such as rice, corn, wheat, barley, and oats are the most commonly used ingredients that provide carbohydrates. Other sources like carrots, apples, and potatoes are becoming increasingly more common as well.

AMOUNTS REQUIRED: There is no definitive recommendation for carbohydrate percentages in diets. In fact, most dog foods do not even include this value on the bag. However, as mentioned above, carbs are an extremely efficient energy source and are an important part of any balanced diet regardless of current trends (see common pet food myths). This is especially true in dogs that are growing, lactating, or pregnant as these animals will have much higher energy requirements that are difficult to meet due to limitations in feeding volumes.


Fiber is a specific type of carbohydrate. Fiber is not metabolized and absorbed in the small intestine like most nutrients. Instead, these molecules are fermented by the normal bacteria that live in the colon. This process promotes and regulates normal bowel function, including the volume and consistency of stool. It is important to monitor fiber intake closely as too much of any one source of fiber can lead to diarrhea, flatulence, abdominal pain, or constipation.

SOURCES: peanut hulls, soybean hulls, beet pulp, cellulose, hemicellulose, bran, guar and other gums, pectin

AMOUNT REQUIRED: No more than 5% for healthy adult dogs. Some specialty foods such as weight loss diets may contain up to 10% to aid in satiety (feeling full).


Proteins are long chains of amino acids that are used as a structural component in almost all the body’s tissues. Although this is the most recognizable contribution of protein in the body, it is important to note that proteins are also crucial for immune and enzyme function. A high quality, highly digestible protein source is an absolute requirement for any good diet as some amino acids cannot be synthesized and must be provided in food. However, proteins cannot be stored in the body, so extremely high protein diets are not necessarily a good thing.

SOURCES: Meat (chicken, beef, fish, venison, duck), Soy

AMOUNT REQUIRED: Minimum of 18% on a dry matter (DM) basis for adult maintenance, minimum 22% for growth (see next section for calculations of dry matter percentages).


Simply stated fat is just stored energy. In fact, fat contains over double the energy volume of protein or carbohydrates. It also aids in the absorption of Vitamins D, E, A, and K. In addition, it provides omega 3 fatty acids that have anti-inflammatory effects throughout the body.

SOURCES: Meat fats (pork, beef, poultry), Oils (vegetable, sunflower)
AMOUNT REQUIRED: minimum 5% of metabolizable energy (ME) for adult maintenance, 8% for growth

Vitamins and Minerals

Vitamins are organic substances that are essential to normal physiology function. Minerals are generally defined as any inorganic material found in foods. Both are required for your pet to be healthy. Any AAFCO certified diet with a “complete and balanced” claim on the label will contain all the vitamins and minerals that your pet requires. Homemade diets, however, are often lacking in this category. Vitamin and mineral deficiencies can have serious consequences. Please consult your veterinarian if you would like to start a homemade diet so you can work together to ensure you are providing all the nutrients your beloved pet needs to be happy and healthy.

funny dog food pictureComparing the nutrient of dog foods

The percentage of each nutrient on the side of a dog food bag is expressed as an “As fed” percentage, meaning that it is specific for THAT particular food and includes moisture content of said food. In other words, you CANNOT just put two bags of dog food side by side and compare percentages of each nutrient. The differing moisture contents of each food will make those percentages meaningless. In order to get an accurate comparison, you have to convert each nutrient percentage to a common value. Remember common denominators when multiplying fractions? This can be done by converting to dry matter basis (DM) or Metabolizable Energy basis (ME). Below is a quick summary and definition of each value as well an example calculation of converting a food into Dry Matter percentages.

Metabolizable Energy (ME):

Gives nutrient density by expressing nutrients as grams per 1000 kcal of energy. Generally considered more accurate but can be more difficult to calculate.

 Dry Matter Basis (DM):

Essentially a measure of the percent contribution of each nutrient (protein, carb, fat) towards the total energy content of the diet. For example, if a diet has a 25% protein content on a DM basis than 25% of the Calories in that diet come from protein. This value accounts for the different moisture contents of food and is relatively easy to calculate

 Calculating Dry Matter

100% – Moisture content = Total Dry Matter %

Convert Total Dry Matter % into decimal

Above Value / % nutrient AS FED= % of nutrient as DM


A food has a moisture content of 25% and a protein of 30% AS FED.

100%-25%=75% Total Dry Matter

75% as a decimal = 0.75

30%/0.75= 40% Protein DM

About the Author fastandy

When not being widely appreciated and acknowledged for his outstanding contributions to the dog blogging community, Andy likes to spend his time filling out social profiles and writing about himself in the third person

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