McGee D, Rhoads G, Hankin J, Yano K, Tillotson J
Am J Clin Nutr. 1982 Oct;36(4):657-63. doi: 10.1093/ajcn/36.4.657.
Within-person variability of nutrient intake is examined using data on 7 consecutive days for 329 men. The variability of nutrient intake within persons differs for the nutrients examined. Some nutrients, such as starch, have small within-person components of variance and are therefore highly reliable even using a single 24-h recall. Others, such a polyunsaturated fatty acids, have large within-person components of variance and are thus less reliable. Within-person variability affects the power of a study to detect differences in nutrient intake between groups and also affects the magnitude of calculated correlation coefficients. For the least reliable nutrient it is estimated that the correlation would be attenuated to two-thirds its true size. Eating patterns in the cohort appear to be nonrandom. Using this nonrandomness of nutrient intake it may be possible to reduce the within-person component of variance using less recalls than is suggested if random eating patterns are assumed.
利用329名男性连续7天的数据，研究了个体内部营养素摄入量的变异性。所研究营养素的个体内部摄入量变异性有所不同。一些营养素，如淀粉，个体内部方差成分较小，因此即使使用单次24小时回忆法也具有很高的可靠性。其他营养素，如多不饱和脂肪酸，个体内部方差成分较大，因此可靠性较低。个体内部变异性会影响研究检测组间营养素摄入量差异的效能，也会影响计算出的相关系数的大小。对于最不可靠的营养素，估计相关性将减弱至其真实大小的三分之二。该队列中的饮食模式似乎并非随机。利用营养素摄入的这种非随机性，与假设随机饮食模式时相比，有可能使用更少的回忆次数来降低个体内部方差成分。
