[Comparison study of food, energy and nutrient intake by 24-hour dietary recall method on two consecutive days versus...

To compare the differences in estimated food, energy, and nutrient intakes between the consecutive 3 days 24-hour dietary recall(24HR)(referred to as the 3-day method) and consecutive 2 days 24HR(referred to as the 2-day method) to provide a basis for the use of consecutive 2 days 24HR in China nutrition surveillance.

Using objective sampling to select participants in northern and southern provinces, dietary data were obtained through consecutive 3 days 24HR, and the average intakes of food, energy and nutrients were calculated for three days from Thursday to Saturday and two days on Friday and Saturday, respectively. The 3-day method was considered as the reference standard method to evaluate the performance of the 2-day method for estimating food, energy and nutrient intakes.

Among 778 participants aged 18-60 years in urban and rural areas of two provinces, the errors of the mean and median of 2-day method for estimating the intake of four major food categories less than 6% compared with the 3-day method, and there were significant equivalencies(P<0.025) and no significant differences in four major food categories group(P>0.05). Of the 24 food groups estimated by the 2-day method, 17 had mean errors within 5%, the largest error was in animal offal(13.45%) and the smallest in fruit(0.15%), and there were significant equivalencies(P<0.025) and no significant differences in seven food groups(P>0.05). For energy and nutrients, the mean and median errors of energy were less than 0.5% and there were significant equivalencies(P<0.025) and no significant differences for energy(P>0.05). Among the 25 nutrients, except sodium, iodine and vitamin E, the mean and median errors of the other 22 nutrients were less than 5%, and there were significant equivalencies(P<0.025) and no significant differences in 16 nutrients(P>0.05).

There was little difference between the two survey method in assessing the intake of high consumption frequency foods, energy and most nutrients at group level, the 2-day method can be used as an alternative to the 3-day method to collect dietary intake data with high consumption rates in the population.