Understanding What’s In What You Eat

Need to Know!

The Law – what has to go on a food label – and what doesn’t!

Certain things have to be included on food labels by law. These include the name of the food, the weight of the food, the ingredients (starting with the largest), use by or best before dates, recommended storage conditions and preparation instructions.

The law does not require nutritional information on packaging, unless a specific nutritional claim is made. When it is included, it too has to follow certain rules. The energy value of the food (joules and calories) must be included, as must the amount of protein, carbohydrate and fat in grams.

The amount of sugar, saturates, fibre and sodium does not have to be included unless a claim has been made regarding the content of these. The information must always be given as values per 100g or 100ml, values per serving size can be given too.

If a food is claiming to be organic it must have certification which will be found on the label – if this is not included then the product is not genuinely organic.

Nice to Know!

Once you have this information it is up to you how you choose to use it!

You have already been advised that a good diet for an active person should be 55–65% carbohydrate, less than 25% fat and 10–20% protein but how do you get this information from a label?

The calculations take into account the differing number of calories per gram of the different macronutrients.

Carbohydrate and protein each contain 4kcal per gram whereas fat has 9kcal per gram. To work out a percentage you need to perform the following calculation:

  1. Multiply the number of grams of the nutrient per 100g of the product by the appropriate number of calories i.e. 4 for protein and carbohydrate or 9 for fat (see below)
  2. Divide this number by the number of calories per 100g of the product (see below)
  3. Multiply this number by 100 to give you a percentage.

E.g. Product containing 6g fat per 100g and 450kcal per 100g

  • 6 x 9 = 54
  • 54/450 = 0.12
  • 0.12 x 100 = 12% fat

What will become apparent is that marketing claims are not always what they seem, particularly those regarding fat content.

As products only have to give information on the number of grams per 100g of the product, if it has 3g of fat per 100g then the product can claim to be 3% fat, regardless of the number of calories per 100g.  You can work out the percentages of your favourite products, but you can’t do this with every product you pick up – shopping would take you days!  So, when dealing with fat content it is easier to look at the ingredient list.

If fat, in any form (oil, butter, lard, cream, cheese etc) is listed in the top three, then the product is probably high in fat.

Fun Facts!

  1. A good example of clever marketing is whole fat milk, which has 4g fat per 100ml, but only 69kcal per 100ml. When calculated this product works out to be 52% fat which is more than most chocolate bars!
  2. Although the food industry is governed by laws stating what must be included on labels and there is legislation to deal with false claims, there are no such controls in the supplement industry! So, be careful when buying dietary supplements – they aren’t always what they seem!
  3. The average person will lose a teaspoon of salt with each bout of prolonged exercise – if you work out twice a week, that’s more than 100 teaspoons per year! But be careful, salt is in pretty much every packaged food you buy.

The easiest way to be sure you know how much fat, salt and sugar you are eating is to buy fresh foods and prepare them yourself.

Mark Foster
Understanding What’s In What You Eat
A Health Tip from Mark Foster