“Relevant, reliable and up-to-date food composition data are of fundamental importance in nutrition, dietetics and health, but also for other disciplines such as food science, biodiversity, plant breeding, food industry, trade, and food regulation’’ Barbara Burlingame (FAO official)
Variation of nutrient contents in foods
Nutrient contents in foods can vary significantly because:
- of environmental, genetic and processing influences such as feed, soil, climate, genetic resources (varieties/cultivars, breeds), storage conditions, processing, fortification and market share;
- each country has its own consumption pattern resulting in country-specific foods, recipes and brand-name foods (commercial foods with the same brand-name can have varying composition due to taste or fortification regulations across borders)
- food biodiversity highly influences the composition of foods: nutrient values may vary up to 1000 times among different varieties of the same foods. This means that the nutrient content of foods can vary as much among foods as among varieties of the same food.
Therefore, each country has specific data needs as they have different compositions of their foods, even if some people think that foods have similar composition among countries due to globalization.
’’Inadequate food composition data and their use may then lead to erroneous research results, wrong policy decisions (particularly in nutrition, agriculture and health), misleading food labels, false health claims and inadequate food choices’’ U. Ruth Charrondiere (FAO official)
Challenges in developing and maintaining food composition tables or databases (FCT/FCDB)
High-quality food composition data should be representative of national food habits and consumption patterns. They should be generated according to international guidelines so that they are comparable and reliable. Well-designed tables and databases should include a good selection of food components and the majority of highly-consumed foods. However, this is often not the case as many tables only include raw foods and a small number of nutrients while processed and fortified foods are lacking.
Whilst many countries have a national or regional food composition tables or databases, most of them contain incomplete, outdated and unreliable data. On the other hand, there are still many developing and some developed countries without such tables or databases. These countries borrow data from other sources, e.g. data are taken from publicly available database such as the United States Department of Agriculture (USDA) or from FCTs/FCDBs from neighboring countries. This may introduce a variety of errors. It is hoped that in the future more high quality analytical data are produced in order to replace those in old tables/databases. For example the outdated Food Composition Table for Use in Africa (1968), is still widely used in many African countries, making the new West African Food Composition Table (FAO, 2012) a good alternative.
Unfortunately, most FCT/FCDB do not include fortified foods or food supplements (containing vitamins and minerals). And whilst some FCT/FCDBs include a few fortified foods, rarely do they include foods with the specific product/brand-names. Therefore, in many countries nutrient intake estimations have been underestimated.
Moreover, food composition activities must be supported by their organizations in terms of providing sufficient human and financial resources and/or the infrastructure needed to carry out the work. This is often only feasible if these resources are endorsed and/or allocated through the policy environment. However, in many countries, food composition activities have to be carried out as voluntary activities as institutions and policies do not recognize the importance of adequate and high-quality national or regional food composition data. Now that food labelling has become mandatory through Codex Alimentarius this situation may change.
Challenge of awareness raising and training
Many users of food composition databases and tables are not aware that food composition data can vary significantly either because of natural differences (e.g. soil, genetics, climate) or because of artificial differences (e.g. due to nutrient definitions or expressions, enrichment, fortification). People are often not conscious of the different nutrient contents between e.g. raw, cooked and processed foods or between the different expressions and definitions of nutrients and their influence on nutrient values. This is the case for many vitamins (e.g. Vitamin A, D or E, or folate versus folic acid) and even for macronutrients (total vs. available carbohydrates). For all these reasons, it should be recognized that food composition data are not simple numbers; a great deal of knowledge is needed to generate, compile, update and use these data adequately. Adequate training in food composition should therefore be included in universities and other formal training of nutritionists, dieticians and other users. The FAO/INFOODS Food Composition Study Guide is an excellent example to widely disseminate knowledge on food composition and biodiversity as it is a distance learning tool which is freely available on the INFOODS internet. It contains all important information and supporting material (Powerpoint presentations) about food composition and biodiversity.
The three pillars of high-quality food composition data
- International standards and guidelines for the generation and compilation of food composition data
- National and/or regional food composition programmes exist and food composition tables / databases are updated regularly
- Professionals are trained in all aspects related to food composition
