Compiling FCDB

Data on the composition of foods are essential for nutrition research, product development, nutrition education, trade of foods and food products between and within countries, and development of nutrition and agricultural policies by government agencies. Food composition data have been compiled into many data bases throughout the world. As the uses of those data increase, a larger number of individuals and organizations become involved in their compilation, and thus the need for guidelines on their gathering, formatting, and documentation increases. This document describes and presents recommendations for the procedures involved with compiling the values for food composition data bases and tables. Specifically addressed are the five major ways to obtain data on the nutrient content of foods:

• direct analysis based on analytical measurements,
• calculated as representative values (e.g., weighted means of several samples),
• gathered from other sources (e.g., taken from other tables or the literature),
• estimated from similar foods (e.g., substitution of data),
• estimated from ingredients (e.g., recipe calculations).

The terms "calculated" and "imputed" are often used for data that are not analytic, "calculated" implying more trustworthiness than "imputed". While many people distinguish between these two terms, there is little agreement on their precise meaning. To avoid conflict, we use the term "estimated" for those data which are not strictly laboratory values.