Technical Abstract: This paper is an introduction to a forthcoming series of articles on Nutritional Metrology, "the Science of Nutritional Measurements." This series will appear in a new publication, Food Testing and Analysis, aimed at the entire food laboratory testing community. Demands for more reliable food testing data required for food labeling regulations, food monitoring and clinical and human nutrition research programs lead to increased demands for a more accurate and reliable measurement infrastructure for food analysis. Food analysis and testing must be traceable to a known and recognizable set of national and international standards. Valid and accurate measurements depend upon use of valid methods of analysis, use of known test sample reference materials and establishment of adequate quality control systems.