In China, the standard approach to collecting accurate dietary data was the three-day household inventory to measure household food consumption and nutrient intake. Measuring individual food consumption was regarded as less accurate and was thought to be unacceptable before the 1980s. A multiple-day household inventory method is time-consuming and expensive, as it requires a high-quality, durable scale and trained field workers. Moreover, the method provides only nutrient intake and food consumption data at the household level. It neither differentiates the intake of guests from
usual household members nor measures food eaten away from home (AFH). For these reasons, it is very difficult to assess nutrition status and conduct a range of studies at the individual level with the inventory method. Nevertheless, nutritionists in China and elsewhere in Asia believe the increased cost and effort are justified by the increased quality of measurement.
Since the 1980s, several large-scale nutrition surveys have been completed to observe the impact of socioeconomic changes on food consumption and chronic diseases in China. However, there has been no systematic analysis of the quality of 24-hour dietary recall, and little work has been done to consider ways to improve these dietary-assessment methods. Although more and more studies and discussions have focused on such methods in the world, minimal research has assessed the reliability of 24-hour dietary recall, and little attention has been paid to improving the quality of the dietary surveys in China.