Murphy Suzanne P
Cancer Research Center of Hawaii, 1236 Lauhala St., Suite 407, Honolulu, HI 96813, USA.
Asia Pac J Clin Nutr. 2008;17 Suppl 1:299-301.
Nutrient standards such as the Dietary Reference Intakes (DRIs) may be used to assess diets of both individuals and of population groups. The goal is to estimate the probability of dietary adequacy (or inadequacy) for an individual and the prevalence of dietary adequacy for a group. The DRI that is needed to estimate the probability of dietary adequacy is the estimated average requirement for a nutrient (EAR), as well as an estimate of the standard deviation of the requirement. The probability of adequacy for an individual should be based on usual long-term intake, because the DRIs apply to a person's usual intake, rather than to intake on only a few days. Due to day-to-day variation in intakes, it is usually necessary to record or observe a person's intake for a large number of days. For population groups, the prevalence of adequacy can be calculated as the average of each person's probability of adequacy, and should correspond to the proportion of the population with nutrient intakes exceeding nutrient needs. A short-cut method to estimating the prevalence of adequacy simply calculates the proportion of intakes that are above the EAR. It is not necessary to have usual long-term intake for each person in the group, but a statistical procedure must be used to remove the effect of day-to-day variation from the intake distribution before the prevalence of adequacy within a group is estimated. With the new DRIs, a more informative assessment of both individual and group intakes is possible.
诸如膳食参考摄入量（DRIs）之类的营养标准可用于评估个体和人群组的饮食。目标是估计个体饮食充足（或不足）的概率以及群体饮食充足的流行率。估计饮食充足概率所需的膳食参考摄入量是营养素的估计平均需求量（EAR）以及需求量标准差的估计值。个体充足概率应基于通常的长期摄入量，因为膳食参考摄入量适用于一个人的通常摄入量，而不是仅几天的摄入量。由于摄入量存在每日变化，通常有必要记录或观察一个人大量天数的摄入量。对于人群组，充足流行率可计算为每个人充足概率的平均值，并且应对应于营养素摄入量超过营养需求的人群比例。一种估计充足流行率的捷径方法是简单地计算高于估计平均需求量的摄入量比例。对于组内的每个人，无需有通常的长期摄入量，但在估计组内充足流行率之前，必须使用统计程序从摄入量分布中消除每日变化的影响。有了新的膳食参考摄入量，对个体和群体摄入量进行更具信息性的评估成为可能。
