Am I Feeding My Pet Too Much or Too Little?

Dave Zanoni

Founder of Purrs McBarkin’ and certified in canine and feline nutrition through Southern Illinois University (SIU). My education is fully independent, with no ties to pet food companies or corporate funding. I studied nutrition because I care deeply about what goes into your pet’s bowl. There’s a clear difference between science and marketing—and I choose science every time. Every product I offer, every conversation I have, and every decision I make is centered on helping pet parents make thoughtful, informed choices that truly support their pets’ health—not the corporate bottom line. I believe in staying curious, always learning, and sharing the latest knowledge—backed by science and built on compassion.

Am I Feeding My Pet Too Much or Too Little? Here’s the Science Behind It.

By Dave Zanoni, Certified Canine & Feline Nutritionist

One of the most common questions I hear at Purrs McBarkin’ is:
“How do I know if I’m feeding my pet the right amount?”

It’s a fair question—and it’s more complicated than the back of a pet food bag will ever tell you.

Let’s dig into the science of how your dog or cat’s daily calorie needs are calculated and why getting it wrong (even slightly) over time can lead to chronic health issues like obesity, malnutrition, joint stress, or immune dysfunction.

🔬 First, Understand RER: Resting Energy Requirement

RER stands for Resting Energy Requirement. This is the baseline number of calories your pet needs each day to simply survive in a resting, non-active state. We’re talking heartbeat, breathing, digestion—basic life support, nothing more.

How is RER calculated?

RER = 70 × (Body Weight in kg)^0.75

Let’s break that down with an example:

If your dog weighs 20 lbs (about 9.07 kg), the math looks like this:
RER = 70 × (9.07)^0.75 ≈ 400 kcal/day

That’s just enough to keep the lights on. It doesn’t account for playtime, stress, growth, cold weather, or daily activity.

🏃‍♂️ Now Add MER: Maintenance Energy Requirement

MER (Maintenance Energy Requirement) builds on RER and adjusts for real life—your dog’s or cat’s age, breed, activity level, reproductive status, health condition, and even emotional state.

Each life stage or activity level has a different MER multiplier:

Life Stage / Condition	Multiplier (× RER)
Neutered Adult Dog	1.6
Intact Adult Dog	1.8
Active Working Dog	2.0 – 5.0+
Puppy (0–4 months)	3.0
Puppy (4+ months)	2.0
Neutered Adult Cat	1.2
Intact Adult Cat	1.4
Kitten (growing)	2.5

So for our 20 lb dog example (RER ≈ 400 kcal/day):
MER = 400 × 1.6 = 640 kcal/day

That’s your target daily intake—not just what’s listed on a generic label.

🍽️ Treats Count Too—Even When the Food Is “Right”

Many pet parents nail the base food quantity but unknowingly overshoot calories with treats.
Treats should not exceed 10% of your pet’s daily caloric intake.

In our earlier example:
10% of 640 kcal = 64 kcal/day in treats

This means a few training bites, a bully stick, or even that “healthy” jerky chew can tip the balance fast—especially in small dogs and cats.

If treats exceed 10%, you risk throwing off the diet’s macronutrient balance (especially protein-to-calorie ratios), and over time this can contribute to weight gain or nutritional imbalances.

⚖️ Why Guessing Doesn’t Work

Eyeballing portions or following generic label charts can be misleading. Most feeding guidelines are based on broad averages—they don’t consider your pet’s muscle mass, metabolism, body condition score, or spay/neuter status.

And if you’re feeding a mix of kibble and canned, or rotating diets, the math gets even fuzzier.

📊 Use Calorie Calculators Made for Real Life

That’s why I created free calorie calculators—to give you science-based feeding estimates tailored to your pet.

👉 Kibble Calorie Calculator
👉 Canned Food Calorie Calculator

These tools use RER and MER formulas under the hood and factor in calorie density so you can feed based on data—not guesswork.

🔎 Still Not Sure? Look at Body Condition

Feeding math is helpful—but how your pet looks and feels is the most honest indicator.

Signs you may be overfeeding:

Loss of waist definition
Difficulty feeling ribs
Lethargy or joint stiffness
Chronic soft stools

Signs of underfeeding:

Visible ribs or hip bones
Low energy
Poor coat quality
Muscle loss (especially along the spine and hips)

If you’re unsure, bring your pet into the shop—I’ll help you evaluate their condition and guide you with no judgment, just science and support.

🧠 Final Thought

Feeding your pet the right amount isn’t about perfection—it’s about awareness.

Whether your goal is weight loss, muscle gain, or just giving your dog or cat a better quality of life, understanding how many calories they really need is the first step toward better health.

So if you’ve ever wondered, “Am I feeding too much or too little?”—now you know there’s a better way to find out.

Let’s stop guessing. Start calculating.
And remember, I’m here to help every step of the way.

Purrs McBarkin’ is an independently owned pet supply store in Hartsville, SC, offering expert guidance and curated products. Visit us at purrsmcbarkin.com.