Making sense of Guideline Daily Amounts
04 October 2007
You may have noticed the term Guideline Daily Amounts or GDAs mentioned on food labels, but what does it mean? Guideline Daily Amounts are a guide to the total amount of energy and nutrients that a typical healthy adult should be eating in a day.
These values are provided on a voluntary basis by the food and beverage and retail industries, to give context to the energy and nutrient content of foods and beverages. By providing consumers with this information, it is hoped that they will have a better understanding of how individual products contribute to achieving an overall balanced diet.
The food and beverage and retail industries derive their GDA values from international, EU and government guidelines that are based on the latest published scientific data on dietary requirements and recommendations. However, differences have been observed between the various systems used, due to the origin of the scientific data reference and minor differences in calculation techniques. Consumers in the UK are already familiar with the concept of GDAs, following the introduction of this on pack information by many manufacturers and retailers in 1998. In continental Europe, GDAs are gradually gaining acceptance. Recently, the Confederation of the Food and Drink Industries of the EU (CIAA) proposed a harmonised industry approach to nutrition labelling across the EU, including the use of standardised GDA values. This would help to eliminate the differences between GDA values that have currently been observed.
GDAs for energy and nutrients
In general, GDAs are available for energy (calories) and the four most important nutrients that may increase the risk of developing some diet-related diseases: fat, saturated fat, sugars and sodium (or salt). GDAs for carbohydrates, protein and fibre may also be given at the manufacturer’s discretion. Guidelines for adults are based on typical requirements for healthy men and women over 18 years of age, of normal weight and/or for weight maintenance. The energy GDA values are derived from estimated average population requirements (EAR) for energy and take account of the current activity levels and lifestyle of an average citizen, which tends to be fairly sedentary. The energy is commonly measured in “kilocalories” (kcal), also referred to as “Calories”: both expressions are equivalent and commonly used on food labels. For an average woman the energy GDA is 2000 kcal and 2500 kcal for an average man: these values are used as a reference to calculate the guideline daily amounts for nutrients. Where it is impractical to provide separate guidelines for men and women, ‘adult’ GDA values are based on GDA values for women, to discourage over-consumption. Guidelines for children have also been developed for both boys and girls. Reference GDAs for children are generally only found on labels or literature associated with products intended specifically for children.
Table 1, provides an example of adult GDAs that you may see on different products in Europe, based on a daily intake of 2000 kcal and derived from EURODIET recommendations (refer to reference 5; for Total sugars, refer to references 6, 7).
Guidelines, not individual targets
For any individual, energy and nutrient requirements may be higher or lower than the published GDAs, based on their gender, age, weight, level of physical activity and other factors. Furthermore, it is unlikely that an individual will achieve their GDA for every nutrient on any one day. For these reasons, GDAs should not be regarded as strict individual targets. Rather, consumers should consider them a benchmark for assessing the potential contribution of a particular product to their daily requirement for individual nutrients.
Vitamins & minerals, the RDAs
Where vitamin or mineral content is declared on the label, this is given as a percentage of the recommended dietary allowance (RDA) rather than GDA, and is regulated by EU food law. Vitamins and minerals need to be consumed in specific amounts for the good functioning of essential metabolic reactions in the body and the preservation of physical health. For this reason, their recommended levels of intake are set higher than the average population requirement (which was the case of GDAs), in order to eliminate any cases of deficiency. The RDA is the average daily intake that will meet the nutrient requirement of nearly all healthy adult people. As with GDAs, this does not mean that those amounts should be taken every day. They represent the average intake over a period of time (Table 2).
Source: Council Directive 90/496/EEC of 24 September 1990 on nutrition labelling for foodstuffs
Visual examples explained
Figure 1 below is an example of a nutrition signpost that you may find on a product pack. To exemplify how this information can be useful to the consumer, a detailed explanation of the energy GDA has been provided: the same principles of interpretation are required to gain a full understanding of the sugar, fat, saturated fat and salt content of this product, allowing the consumer to determine how this product fits in his overall diet.
Figure 1. Example and explanation of a signpost
Figure 2 provides an example of nutritional tables that consumers may see on the back of product packaging. The figure compares two similar kinds of breakfast cereal. In this case, type 2 cereal would benefit people who have a low consumption of dietary fibre.
Figure 2: Comparison of the nutrition information of two back of packs of breakfast cereals
Putting theory into practice
In a shopping or a cooking context, GDAs are designed for guiding consumers’ choices: for people concerned by the amount of salt they consume, these values can assist with the identification of the lowest source between two products.
GDAs can help in promoting a better understanding of how different foods contribute to a well balanced diet by indicating which foods should be consumed now and again, and those that could be consumed more frequently.
It is however important to note that there is still very little known about how such labelling systems are actually used on a day-to-day basis and further research is required to understand how consumers use this information in practice.
- Institute of Grocery Distribution (2006) Best Practice Guidance on the Presentation of Guidelines Daily Amounts.
- Council Directive 90/496/EEC of the 24 September 1990 on nutrition labelling for foodstuffs.
- CIAA (2006) Recommendations for a Common Nutrition Labelling Scheme.
- COMA (1991) Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. (Report on Health and social Subjects). HMSO, London.
- EURODIET (2001) Nutrition & Diet for Healthy Lifestyles in Europe. Core Report.
- INPES (2002) La santé vient en mangeant. Guide alimentaire pour tous.
- FAO/WHO (2003) Diet, Nutrition and the Prevention of Chronic Diseases. Report of an expert consultation. WHO, Geneva
- FAO/WHO (1998) Carbohydrates in Human Nutrition. FAO food and nutrition paper no. 66. FAO, Rome.