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2 Dec 2023

The daily amount of food you feed your pet dog or pet cat will be the most indispensable factor that will determine if they will grow up healthy and continue to stay healthy, for as long as possible.

Basically, we are witnessing a lot of confusion.

We often see newly bought or adopted puppies or kittens that are brought to our clinic with very poor body condition scores and poor muscle development, and are tremendously frustrated when the new owner-custodian(s) reiterate that they were taught by the pet shops or previous owner to feed

We also see many adult pet dogs that are emaciated because owner-custodians are rigidly providing a fixed amount of food to their pets daily, solely based on the recommended feeding chart printed on the back of the food package, without taking into consideration the individual’s daily metabolic requirement, activity level, and growth/ maintenance and repair cycles. 

We have observed the misrepresentation and misinterpretation of feeding charts and nutritional data for many years, causing so many baffling nutrition concepts amongst the owner-custodians. 

We are also gobsmacked by the ongoing erroneous propaganda being wilfully broadcasted online about food-related therapies for healthy and diseased pets.

For this article, we are going to try to simplify and decipher the amount of food to feed our pet cat and pet dog per day based on the kilocalories available in a specific can or cup of food, together with you. 

“2 Chinese soup spoon of dry food 2 times a day”.

In general, the law in most countries that make and sell pet food routinely will require that the manufacturers list the following key information on their pet food labels:

1. Brand Name

2. Product Description - including species of animals intended, for complete or complementary feeding, AAFCO nutrient profiles met.

3. Composition - ingredients list arranged in descending order by weight.

4. Guaranteed Analysis -  Information about nutrient levels in percentage

5. Additives - if applicable

6. Feeding Instruction - how much food to feed per day.

7. Weight of product - per can or per pack

8. Manufacturer's information and contact information 

9. Metabolisable Energy - in kilocalories per can or kg of food

10. Best Before Date and Batch Code - usually printed on the can


But the only truly, valuable information on the finely printed list of words is the Metabolizable Energy (ME) or Energy Density value on the feeding instructions.

ME is the usable calorie or energy in a can or a cup of pet food available to be utilized by the pet’s cells and tissue for general function, growth, or repair.

Metabolizable Energy Value for cat and dog food should be easily available for both canned and dry food.


ME = 43.8 kcal/ 100g

ME = 463 kcal/ can

Other knowledge that will help to establish the amount of food to feed per day includes:



1. Body Condition Score (BCS)

Check the body of the pet.
Score 1 (skeletal) -9 (morbidly obese)

2. Muscle Condition Score (MCS)

Check the body of the pet.

3. Resting Energy Requirement (RER)

Calculated based on body weight.

4. Lifestages/ Lifestyle Factors

How old? Activity levels.

5. Daily Energy Requirement (DER)

Calories needed per day.

6. Metabolizable Energy (ME)

Calories in a canned / in 100g/ 1 kg of food.

To determine if the pet cat or dog has a good body condition score and has well-developed muscle, we must inspect the subcutaneous fat layer and muscle distribution on the body.


When palpating the spinal cord, pelvic bone, and ribs with an index finger there should not be a prominent protrusion with no muscle or subcutaneous covering to protect these vital bone structures.


Please refer to CATS and DOGS for a more detailed explanation of Body Condition Score (BCS) and Muscle Condition/ Developmental Score (MCS).


Assuming, we are studying a 14kg neutered dog that has a BCS 4 and MCS indicates Mild Muscle Loss, and we would like the body weight to become 15.5kg with a higher and better BCS (5) and MCS (normal muscle development) level.


We, fundamentally, need to feed the 14kg dog enough energy/calories for the body to perform the basic and essential body functions like digestion, respiration, blood circulation, and cognitive functions.


This is commonly known as the

Resting Energy Requirement (RER).


The equation used by the pet nutrition industry (as well as veterinarians) to reach RER (kilocalories needed per day) is (Body Weight in kg x 30)+70.

For example:

The RER of the 14kg dog

= (Body Weight in kg x 30) +70

= (14kgx30) +70

= 490 kilocalories per day.


This amount of food intake will keep the 14kg dog, who is not moving or not doing any other activity, (barely) alive and not reaching the desired body weight with a good distribution of muscle mass and subcutaneous layer.


To make sure that the 14kg dog thrives, you will need to multiply the RER obtained with one of the life stage/ lifestyle factors provided below.





< 4 months old
>4 months old

RER x 2.5
RER x 2.5

RER x 3
RER x 2


Neutered/ Spayed
Prone to obesity
Weight loss
Weight gain

RER x 1.2
RER x 1.4
RER x 1
RER x 0.8
RER x 1.5

RER x 1.6
RER x 1.8
RER x 1.4
RER x 1
RER x 1.2-1.8




RER x 2
RER x 5


7-10 year old
> 10 year old

RER x 1
RER x 1.2

RER x 1.4
RER x 1.2

* Calories provided for senior pets should derive more from animal-based protein, instead of carbohydrate or fat/oil.

In this example discussed, the estimated Daily Energy Requirement (DER) for the 14 kg dog to thrive and gain weight will be the calculated RER multiplied by the weight gain factor ranging from 1.2 to 1.8 based on the severity of the BCS and MCS.

Let us multiply with the midpoint of about 1.5:

Daily Energy Requirement (DER)

= Resting Energy Requirement x Midpoint of weight gain factor

= [(14x30) + 70] x 1.5

= 490 x 1.5 

735 Kilocalories per day

Therefore, the 14 kg dog must consume 735 Kilocalories per day to thrive and gain weight.

Now, examine the food you have decided to feed.

Let us use a canned food with a Metabolisable Energy (ME) of 463  kilocalories per can as an example.


Number of canned food per day

= DER / ME

= 735/463

= 1.58 can per day

~ 1.5 can per day


Therefore, to increase the weight of the 14 kg dog to 15.5kg, we should start by feeding 1.5 cans of the chosen canned food daily to meet the estimated DER for weight gain.


The emphasis must be placed on the fact that this equation will only provide us with an “estimated DER value.”

This will be considered the starting point only.


The pet dog in question should be weighed every 2 weeks to monitor for weight gain and adjustments must made accordingly.

If the weight gain Is too slow, the DER should be recalculated.

Daily Energy Requirement (DER)

= Resting Energy Requirement x Highest weight gain factor

= [(14x30) + 70] x 1.8

= 490 x 1.8 

882 Kilocalories per day

Number of canned food per day

= DER / ME

= 882/463

= 1.9 can per day

The food fed per day to the dog thus can range between 1.5 to 1.9 (rounding off to 2 cans) cans of food until the body weight reaches 15.5kg.

Assuming, the 14 kg dog reaches 15.5 kg after 3 months, we will then calculate a maintenance feeding protocol to keep the weight at 15.5kg with the correct muscle and subcutaneous layer distribution by adjusting the DER in the chosen food as follows:


Daily Energy Requirement (DER)

= Resting Energy Requirement x Maintenance factor for a neutered adult dog

[(15.5x30) + 70] x 1.6

= 856 kilocalories per day

Number of can food per day

= DER / ME

= 856/463

= 1.85can per day


The muscle and subcutaneous layer distribution can be further fine-tuned by altering the protein percentage in the food offered, but we will discuss protein intake and adjustment in this article.



If your pet is below 1 year old, please expect that it should have a good layer of blubber – no baby animals should be lean or resemble a supermodel.


Growing animals must have adequate nutrition for the growth and development of all vital organ systems, daily basic metabolic expenditure, and a slight excess for just-in-case situations.

Please refer to the recommended life stage/ lifestyle factor (2-3, not for giant breeds like Great Danes) needed to achieve a correct DER for proper growth and development.


If your pet is more than 1 year old, please check that the pet has developed or is developing and maintaining a good and strong muscle layer protecting all the vital bone structures.

Most commercial pet food will always state on their generic feeding chart that the recommended feeding amount is meant for an “average adult dogs with normal activity levels.”


Please do not assume that the apparent “normal activity levels” is the same for every pet dog or pet cat.


A neutered Ragdoll cat will not have the same metabolic rate or activity expenditure as a neutered Bengal cat.


You should determine and adjust the calorie requirement based on the pets BCS and MCS and numerical weight changes, at least monthly.


If your pet is more than 7 years old, please check if sarcopenia has started, you will then need to reduce the calorie intake and increase the protein intake to maintain the muscle mass, tissue and ligament elasticity that helps hold up the bone structures.

Author Contributions

Dr. Denise Ng BSC BVMS

Conflict of interest

The author declares that there is no conflict of interest.


The author received no specific grant from any funding agency in the public, commercial or not-for-profit sectors for the preparation of this review article.


1. AAFCO: Consumers; Understanding Pet Food: Calories. Accessed 27 Oct 2023.

2. AAFCO: Animal Feed Labeling Guideline 2020. Accessed 10 Oct 2023.

3. AAFCO: How to understand a dog or cat food label. 

Accessed 10 3 Nov 2023

4. Accessed 3 Nov 2023

5. Lisa M. Freeman, DVM, PhD, DACVIM (Nutrition). (28 Dec 2020). What Is Guaranteed about the Guaranteed Analysis?  Accessed 29 Oct 2023.

6. Deborah E. Linder, DVM, MS, DACVIM (Nutrition). (11 Nov 2016). What are these numbers? Nutrition Math 101  Accessed 29 Oct 2023.

7. David Dzanis, DVM, PhD, DACVN. Pet food labels: Cracking the code (Proceedings). Accessed 30 Oct 2023.

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