Centre for Rural Health, Faculty of Health, University of Tasmania, Locked Bag 1322, Launceston, TAS, 7250, Australia.
Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia.
Nutr J. 2018 Jan 12;17(1):7. doi: 10.1186/s12937-017-0309-7.
Within- and between-person variation in nutrient intake is well established, but little is known about variability in dietary flavonoid intake, including the effect of seasonality.
Within- and between-individual variability of flavonoid intake, and intake of flavonoid subclasses was examined in older adults (n = 79; mean age 70.1 y (range: 60y-80y)), using three separate 4-day weighed food records (WFR) collected approximately 4 months apart. The effects of seasonality were also examined. Mixed-effects linear regression models were used to estimate within- and between-individual variance components for flavonoids and subclasses. The number of days of dietary assessment required for a high level of hypothetical accuracy was calculated from variance ratios.
Within- and between-individual variability was high for flavonoid intake, and intake of flavonoid subclasses, with variance ratios > 1. It was calculated that six days of WFR data are required for total flavonoid intake, and between 6 and 10 days was required for flavonoid subclasses. There was no effect of seasonality for total flavonoid intake or intake of flavonoid subclasses, with the exception that flavan-3-ol and flavanone intakes which were relatively low in summer, and in summer and winter, respectively.
While the effects of seasonality on total flavonoid intake may be small, within- and between-individual variation associated with flavonoid intake assessment appears to be substantial across 12 days of WFR data in older adults. It is recommended that a minimum of 6 days of weighed food records are collected to minimise the impact of within- and between-individual variability on total flavonoid intake assessments in this population.
营养摄入的个体内和个体间变异性是众所周知的，但关于饮食类黄酮摄入的变异性知之甚少，包括季节性的影响。
在 79 名老年人（平均年龄 70.1 岁（范围：60 岁-80 岁））中，使用三次单独的为期 4 天的称重食物记录（WFR），大约相隔 4 个月收集，检查类黄酮和亚类的摄入个体内和个体间变异性。还检查了季节性的影响。使用混合效应线性回归模型估计类黄酮和亚类的个体内和个体间方差分量。从方差比计算出达到假设准确性高水平所需的饮食评估天数。
类黄酮摄入和亚类的个体内和个体间变异性很高，方差比>1。计算得出，需要 6 天的 WFR 数据来测量总类黄酮摄入量，而类黄酮亚类则需要 6 到 10 天。总类黄酮摄入量和类黄酮亚类的摄入没有季节性影响，除了在夏季和冬季分别相对较低的黄烷-3-醇和黄烷酮摄入量。
虽然季节性对总类黄酮摄入量的影响可能很小，但在 12 天的 WFR 数据中，与类黄酮摄入评估相关的个体内和个体间变异性在老年人中似乎很大。建议至少收集 6 天的称重食物记录，以最大程度地减少个体内和个体间变异性对该人群总类黄酮摄入量评估的影响。
