The use of summary statistics for sample size allocation for food composition surveys and an application to the potato group

Abstract

To give a quantitative guide to sample size allocation for developing sampling designs for a food composition survey, we discuss sampling strategies that consider the importance of each food; namely, consumption or production, variability of composition, and the restrictions within the available resources for sample collection and analysis are considered., Here we consider two strategies: ‘proportional’ and ‘Neyman’ are discussed. Both of these incorporate consumed quantity of foods, and we review some available statistics for allocation issues. The Neyman optimal strategy allocates less sample size for starch than proportional, because the former incorporates variability in the composition. Those strategies improved accuracy in dietary nutrient intake more than equal sample size allocation. Those strategies will be useful as we often face sample size allocation problems, wherein we decide whether to sample ‘five white potatoes and five taros or nine white and one taros’. Allocating sufficient sample size for important foodstuffs is essential in assuring data quality. Nevertheless, the food composition table should be as comprehensive as possible.

Keywords::

• Sampling
• sample size allocation
• potatoes
• production
• dietary assessment
• variability

Declarations of interest

The authors are grateful to the anonymous referees for their constructive comments. I hereby declare that there are no interests that could potentially conflict with our role as researchers in the national food research institute of Japan.