A pet dog consumes 300 g of dry food per day. The food composition is 20% protein, 30% fat, 40% carbohydrate, and 10% fibre. Calculate the total energy content in kilocalories (kcal) available from protein, fat, and carbohydrate.

Step-by-step solution

1. 1. Find grams of each nutrient: 300 g × 0.20 = 60 g protein; 300 g × 0.30 = 90 g fat; 300 g × 0.40 = 120 g carbohydrate.
2. 2. Use caloric values: protein = 4 kcal/g, fat = 9 kcal/g, carbohydrate = 4 kcal/g.
3. 3. Energy from protein: 60 g × 4 kcal/g = 240 kcal.
4. 4. Energy from fat: 90 g × 9 kcal/g = 810 kcal.
5. 5. Energy from carbohydrate: 120 g × 4 kcal/g = 480 kcal.
6. 6. Sum energies: 240 + 810 + 480 = 1530 kcal.
7. 7. Fibre is indigestible and not counted in kcal calculation.
8. Thus the dog receives 1530 kcal per day.

Concept tested: Caloric calculation from macronutrients

Published 4 October 2026 · How this solution was prepared and checked