Evaluation of the 24-Hour Individual Recall Method in China

We compared two dietary survey methods using the 1991 nationwide China Health and Nutrition Survey. Data were collected over three consecutive days by 24-hour dietary recall and a household inventory for 3,563 households with 13,606 individuals. We studied the absolute difference between the two methods and the relative differences expressed as dietary in take per capita per day. There was only a 74-kcal difference between the methods for average daily calorie intake; the relative difference was 1%. Ratios were larger for average daily protein (5%) and fat (3%) intakes. Analysis of covariance was used to compare the means of the intakes of nutrients when adjusting for other confounding variables. The largest difference was in households with guests eating at home, where fat intake was significantly higher. Particularly important was an adjustment for household cooking oil consumption used to modify the recall results. Removing this adjustment greatly expanded differences in the two methods.