Lewis C J, Beloian A M, Yetley E A
Clinical Nutrition Branch, Food and Drug Administration, Washington, D.C. 20204.
J Am Diet Assoc. 1988 Dec;88(12):1545-52.
The intake of cola beverages from two national surveys (NFCS 1977-78 and NHANES II) was used to examine certain assumptions important to a mathematical model employed to estimate dietary exposure to substances in food. The assumptions center on the relationship between frequency of consumption and serving size and on the constancy of serving size within age groups. Results showed the frequency of cola consumption was associated with 55% to 83% of the variability in cola intake and that mean cola serving size was not linearly related to frequency of consumption. However, while upper-level (90th + percentile) cola consumers consumed more frequently, they also had larger than average serving sizes. Therefore, because the model incorporates a standard serving size, it significantly underestimated (p less than .01) intake for the two groups of upper-level consumers examined. Furthermore, comparisons for cola serving sizes reported in the surveys showed differences by sex as well as systematic differences between the surveys in that the average difference between age and sex groups within each survey was similar, but NFCS 1977-78 had a larger average size for each group than did NHANES II. Attention should be given to the nature of the food consumption databases used for estimating dietary exposure because systematic bias may cause considerable differences in estimation.
利用两项全国性调查（1977 - 1978年全国食物消费调查和第二次全国健康与营养检查调查）中可乐饮料的摄入量，来检验对用于估计食物中物质膳食暴露量的数学模型很重要的某些假设。这些假设集中在消费频率与食用量之间的关系以及各年龄组内食用量的稳定性上。结果显示，可乐消费频率与可乐摄入量55%至83%的变异性相关，且可乐平均食用量与消费频率并非线性相关。然而，虽然高消费水平（第90百分位数及以上）的可乐消费者消费频率更高，但他们的食用量也高于平均水平。因此，由于该模型采用了标准食用量，它显著低估了（p小于0.01）所研究的两组高消费水平消费者的摄入量。此外，调查中报告的可乐食用量比较显示出性别差异以及调查之间的系统性差异，即每次调查中年龄和性别组之间的平均差异相似，但1977 - 1978年全国食物消费调查中每组的平均食用量都比第二次全国健康与营养检查调查中的大。在估计膳食暴露量时，应注意所使用的食物消费数据库的性质，因为系统性偏差可能导致估计结果出现相当大的差异。
