For almost all countries some information is available on the nutritional situation of the population. This information should be collected before starting a nutrition survey since it

• provides important information for the planning process and
• yields complementary information for analysis and interpretation of data.

1. Scientific literature
2. Data from national literature and/or international institutions
3. Nutritional information obtained directly in the local setting.

2.1 Scientific Literature

Literature searches for relevant scientific nutritional articles can be made using special computer software with CDROM or the Internet:

• Current Content (Life Science),
• Medline (e.g. http://www.ncbi.nlm.nih.gov/PubMed/ ).

The search for relevant articles requires one or several index words in the English language, for example:

nutritional status, malnutrition, anemia, IDD, or xerophthalmia

Pakistan, Brazil, or Sahel

Quechua, Bantu, or casts.

• the authors' names and addresses,
• the title of the scientific article,
• the literature citation (e.g., Am J Clin Nutr 1994;60:36-41.)

The quality and relevance of articles are not uniform. The following criteria should be used for evaluation:

• the reputation of the scientific journal
• the quality of the presentation.

2.2 Data obtained from national and international institutions

Information from published and unpublished national as well as from international institutions is available and may complement information from scientific literature.

Multilateral and bilateral organizations can also be contacted at their respective offices in most countries, usually in the capital city.

Besides international organizations, most national agencies, such as ministries of health, agriculture, education, planning and related areas can provide valuable information. Similarly, in some countries there are ministries of land reform, water resources, women's affairs, family planning and social affairs, urban development, etc. The country-specific political and bureaucratic delineations of ministries and their subordinate offices have to be considered.

As literature from these sources often fails to include methodology, and there is sometimes a risk of political influence on the contents of publications by government institutions, the validity of these data should be carefully reviewed.
 

2.3 Information obtained directly in the local setting

Chapters 2.1 and 2.2 have dealt with the collection of scientific and technical information based on literature review and to a lesser or greater degree on official statistics. However, actual experiences in everyday life can provide valuable supplementary information about the local situation. Only with the help of many observers from as many different points of view as possible can precise intervention measures successfully be found. In this case, sociologists, anthropologists and psychologists can provide valuable insight. The explanation of the causes of the nutritional situation of a particular community group leads to a greater understanding of the environmental conditions, in terms of social and cultural factors that determine the life of the community concerned.

Valuable information that would be difficult, if not impossible, to collect through quantitative methods, such as epidemiological techniques, can be obtained through qualitative methods, such as focus group discussions. Two examples are given below:

1. It is extremely difficult to establish whether there is a vitamin A deficiency in a certain area. Deficiency can be determined only through a large random survey in which blood samples are analyzed using an expensive assay procedure. Measurement of the prevalence of xerophthalmia (blindness caused by vitamin A deficiency) is also very difficult, and this symptom occurs only in cases of extreme vitamin A deficiency. If there is no xerophthalmia in a region, it is still possible to find many people suffering from vitamin A deficiency. However, information on the problem of vitamin A deficiency can be obtained through discussions with the target groups, e.g., inquiring whether there are words for night blindness in the local language,
2. The word "kwashiorkor," used to describe symptoms of protein deficiency, originates from Ghana and means "the displaced child ." It is a euphemism used by village people when speaking about imminent death due to protein-energy-deficiency.

In conclusion, methods of social sciences may provide very important complementary information about the nutritional situation and help to put the data gathered by natural science methods into the proper context.
 

2.4 Survey of structural data

Before embarking on door-to-door interviews, relevant community structural data on the village or suburb and region must be obtained for a nutrition survey. This is particularly important to put the results of the survey into the proper context of the overall situation of the province or country. For example, a 20% undernutrition rate in a population can be low if the general prevalence in a country is 40%, and it can be high if the general prevalence is only 5%. Consequently, nutritional data have to be set within the overall demographic, socioeconomic and ecological framework.

Therefore, it is necessary to obtain demographic, economic, ecological and other information, such as: Do many families migrate in or out of the survey area? Are there any unusual climatic conditions at the time of the survey? Is the country going through an economic crisis?

Other important structural data to consider are:

1. Growth of the Gross Domestic Product (GDP).

The GDP growth reflects a country's economic structural environment and assists in the interpretation of other indirect indicators such as:

• Agriculture (e.g., fertilizer consumption per ha of cultivated land, agricultural output).
• Education (e.g., teachers per 10,000 inhabitants, school attendance rates, % illiteracy)
• Health (e.g., doctors per 10,000 inhabitants, hospital beds per 10,000 inhabitants, infant mortality)

Exact demographic data of the project area are necessary to identify the target group and to plan intervention measures. These data include if possible:

• Population density (number of people/km²)
• Annual population growth (%)
• Population migration rate (%)
• Birth rate (%)
• Breakdown (%) of the population by age group (e.g., 0-5 months, 6-11 months, 1-4 years, 5-9 years, 10-17 years, 18-29 years, 30-39 years, 40-49 years, 50-59 years, 60 and more years)
• Life expectancy at birth for men and women (years)
• Infant mortality (%)

In many parts of the world, water is a limiting resource for agricultural production and living conditions. Particularly in marginal regions, rainfall patterns may differ substantially in relatively small geographical areas. Therefore, information should be collected on the amount and yearly distribution of precipitation. Inadequate rainfall can cause a precarious nutritional situation. To do this, one should begin with the survey month and then trace back over the most recent 12 months. Rainfall measurements can generally be obtained from meteorological institutes or agricultural agencies in the district or state capital. In certain areas, factors other than rainfall data, such as frost and hail, also exert an effect.

Table 1. Rainfall data in the project area
 

Month	Average annual rainfall over the last 10 years (mm)	Observed rainfall over the last 12 months (mm)

Structural data can be sought from the statistical yearbooks at local government agencies. However, it is advisable to ask also for data from officials in the capital city, because the data are often more readily obtainable at the capital than in provincial areas due to centralization.