How it works
Step one: Resting Energy Requirement (RER) = 70 × body weight(kg)^0.75 — the calories needed for basic life functions (breathing, heartbeat, body temperature). Step two: multiply by a life-stage factor (MER): growing puppies/kittens ×2-3, neutered adults ×1.2-1.6, weight loss ×0.8-1.0, hard-working dogs up to ×2+. This is the standard method from the WSAVA nutrition guidelines used in veterinary clinics.
Example: a 5kg neutered adult cat has RER ≈ 70×5^0.75 ≈ 234 kcal, MER ≈ 234×1.2 ≈ 280 kcal/day. On a 380kcal/100g dry food that's ≈74g per day, split into two 37g meals.
Three practical tips
- • Weigh the food: measuring cups can be off by ±20%. A kitchen scale (0.1g) is the best pet purchase you'll make.
- • Count treats in the total: keep them under 10% of daily calories; use kibble as training rewards.
- • Re-weigh your pet every 2 weeks: the formula is a starting point — adjust ±10% based on the weight trend.
FAQ
Why do pets gain weight after being spayed/neutered?
After neutering, sex-hormone decline lowers basal metabolism by ~20-30% while appetite rises. Switch to the “neutered” calorie tier proactively and weigh regularly — the single most effective obesity prevention.
Can cats just eat less to lose weight? Why is feline weight loss slow?
Cats must lose weight very slowly (≤1% body weight per week): crash dieting triggers hepatic lipidosis (fatty liver), which can be fatal. Feline weight loss should be veterinarian-guided, typically with a prescription diet, precise weighing and indoor play.