An important part of choosing healthy nutritious food is knowing how to read food labels. Unfortunately labels have their own language and it is not always easy separating fact from fiction. The best starting point is learning how to decipher what a manufacturer has to tell you, as opposed to the information they volunteer in order to convince you to buy.
All manufacturers are required to list their ingredients in descending order according to their relative proportion by weight. Although by no means an exact measure, this list will give you an indication of the relative amounts of the different ingredients that make up the food. Be aware that some manufacturers will use several different kinds of sugar (fructose, lactose, maltose, molasses, treacle, golden syrup, icing sugar, honey) or fat (shortening, vegetable fat, vegetable oil, beef fat, butter, margarine, cocoa butter, canola oil, milk solids) so that each one will be present in a smaller proportion and will not be seen to be a major ingredient in the product.
Fat, carbohydrate and protein content determine the energy provided by food. Food energy is measured in either kilojoules (kj) or calories (cal) (American usage). To change kilojoules to calories you divide kilojoules by 4.184 (calories = kilojoules/4.184).
Fat provides 37 kj per gram (9 cal). Carbohydrate 16 kj (4 cal) and protein 17kj (4 cal). You can use the nutrition panel on foods to estimate the percentage of total kilojoules provided by each of these nutrients. Simply multiply the above kj levels per gram by the number of grams per serving then divide this figure by the total kilojoule level of the product. The average person should aim for a daily energy (kj) intake made up of 50% protein, 40% carbohydrates and 10% fat. These are general guidelines only and will vary between individuals depending on a number of factors which may include physical activity level and weight loss goals.
When comparing products for energy, fat, sugar and sodium content, be sure to check that the serving size is consistent across all the products. Some manufactures give smaller serving sizes than others, so make sure you are comparing equal amounts. Make sure to base your comparisons on the per 100 gram information rather than the per serving information.
Salt and Sugar Content
The body's need for sodium is estimated at 900 to 2000 milligrams per day. However, the average person takes in 10 to 20 times as much salt as required, much of which comes from processed foods. The true name for salt is sodium chloride and ingredient lists may classify salt under either title. If the nutritional panel is present it is possible to determine the amount of salt in the product by looking at the sodium content.
Be aware of hidden salts in processed foods. For example, a vegemite sandwich provides approximately 700 milligrams of sodium, of which only 150 comes from the vegemite and the rest comes from the processed bread and margarine.
To find out the sugar content of a food, you have to look at the total carbohydrate per serve. For example, the total carbohydrate per 100 grams may be listed as 50 grams, including a sugar listing of 30 grams. This means that 30 grams of that 50 grams total carbohydrate is sugar. A general rule is try to keep sugar at less than 7 grams per serve as over-consumption will lead your body to produce excessive amounts of insulin - affecting your body's ability to use stored fat for fuel.