Cut-out and Keep Guide...Calculating the Energy Content of Pet Food

Introduction

Why is it important to know the energy content of pet foods? Because if the energy content of the food(s) and the quantity of food(s) consumed is known, it is possible to determine how much energy a pet is being fed. This in turn will enable the clinician to provide more precise feeding recommendations to an owner, advice which is particularly important for clients who are in the process of changing their pet’s diet or are feeding multiple diets. owners may not appreciate that feeding guides can vary between pet food manufacturers, and that different manufacturers may have different approaches to estimating a food’s energy content.

Knowing the energy content of a pet food also means that different diets can be accurately compared. By normalizing to a fixed energy content it is possible to compare nutrient content, or other factors such as cost, across a range of quite different foods, e.g., one can accurately evaluate the difference between a wet and a dry diet. Some pet food manufacturers provide information on the energy content of their diets, but mandatory legislation varies from country to country and there is no standard method as to how the energy content should be calculated. The approach outlined in Table 1 provides a consistent way to estimate the energy content across a range of foods for both dogs and cats.

Foods differ in the amount of energy they contain, and this is primarily a function of the amount of moisture, protein, fat and carbohydrate present, and (in the case of the macronutrients) their respective digestibilities. Typically dry foods are more energy-dense per unit weight than wet foods; the energy content of wet foods can vary from 70-130 kcal/100 g of food, compared with dry foods that can vary from 280-480 kcal /100 g of food.