“Are nutrition labels accurate?”,
Written by: Tracey Strudwick, Nutritional Therapist
Aside from being a legal requirement, labels displaying the nutritional value of packaged foods help us make healthy choices between products, but should we take nutrition labels with a pinch of salt?
Since December 2016 in the UK, it has been mandatory for most packaged foods to display a nutrition label on the back of the pack. According to the Food Standards Agency, legislation requires the nutritional information on food labels to be clear, accurate, up-to-date, and not misleading, so that consumers can make informed decisions at the point of sale.
This is particularly relevant in light of recent public health concerns regarding energy (calories), saturated fat, sugar and salt intakes in the UK, and increasing awareness of the intake of nutrients required for good health.
Labelling on the front of the pack is voluntary but manufacturers often use this in the form of ‘traffic-light’ labelling. This red, amber, green coding aims to give at-a-glance information to consumers about how much energy (calories), fat, saturated fat, sugar and salt is contained in the product.
Measurements on the mandatory back-of-pack label include calories, fat (and saturates), carbohydrates (and those from sugars), fibre and protein.
Nutrient quality of natural foods
Values stated on the packaging are ‘typical’ or average values, since the composition of natural foods has several variables. The nutrients contained in plant foods vary according to the climate and season, and the quality and composition of the soil in which they were grown.
Nutritional quality of animal foods is affected by the genetic propensity of the animal, as well as the conditions in which it was reared (for example indoor or outdoor poultry, wild or farmed salmon), and the animal’s diet (for example grass-fed beef can have up to five times more omega-3 fatty acids than grain- or corn-fed beef).
Other variables include types of manufacturing processes used, and transport and storage of the products.
Measuring the nutrient content of foods
Scientists working for food manufacturers will employ analytical methods that can be used to determine the nutritional value of food, such as the Kjeldahl method (protein), liquid chromatography (carbohydrates), and gas chromatography (fats). The manufacturers can then compare their products to a database of generally acknowledged nutritional values for food products. In the UK this is McCance and Widdowson’s The Composition of Foods Integrated Dataset.
Manufacturers may use this food composition data to analyse nutrition values of foods from suppliers, but there are limitations: data may not always be accurate, or appropriate for their ingredients, since infrequent updates mean that the data can be out of date and the limited number of foods to choose from doesn’t reflect the variety of products on supermarket shelves.
In addition, current legislation in food manufacturing allows for an error margin of 20% either side of the labelled value, so you might be eating 20% more calories, or 20% less fibre than your label suggests.
It’s important to remember that an unprocessed, wholefood diet is the optimum way to eat for good health, so cutting down on packaged foods and focusing on fresh vegetables and fruit, good quality protein, wholegrains, beans and pulses, is the best way to avoid navigating food labels.
