Instituto de Nutrição Josué de Castro, Universidade Federal do Rio de Janeiro, Brasil.
Cad Saude Publica. 2010 Nov;26(11):2101-11. doi: 10.1590/s0102-311x2010001100011.
For dietary intake assessments, one needs to know the minimum 24-hour recall or food record replications that are required to estimate usual energy and nutrient intake and to classify subjects correctly according to their nutrient intake. Data from two different studies on dietary intake that were carried out with 300 adults and 169 adolescents in the Rio de Janeiro Metropolitan area, Brazil, were analyzed. To estimate the number of replications two methods were applied: one based on the variances ratio, the other based on the within-subject variance alone. The most important results found were the requirement for 14 replications for boys and men, 15 for girls, and 23 for women in order to estimate energy intake with a precision of 90%. Also four replications for boys and seven for men, girls and women are required to classify individuals' energy intake with a correlation coefficient of 0.9. Due to the within variance in food intake, a larger number of replications is required to obtain estimates of usual intakes than is needed to classify subjects according to levels of dietary intake.
对于膳食摄入量评估，需要知道估计通常能量和营养素摄入量所需的最小 24 小时回忆或食物记录重复次数，并根据营养素摄入量正确分类受试者。分析了在巴西里约热内卢大都市区进行的两项针对 300 名成年人和 169 名青少年的不同饮食摄入研究的数据。为了估计重复次数，应用了两种方法：一种基于方差比，另一种仅基于个体内方差。最重要的发现是，为了以 90%的精度估计能量摄入，男孩和男性需要 14 次重复，女孩需要 15 次重复，女性需要 23 次重复。为了以 0.9 的相关系数对个体的能量摄入进行分类，男孩和男性需要 4 次重复，女孩和女性需要 7 次重复。由于食物摄入量的个体内差异，获得通常摄入量的估计值所需的重复次数多于根据饮食摄入量水平对受试者进行分类所需的重复次数。
