期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1988
卷号：34
期号：5
页码：459-467
DOI：10.3177/jnsv.34.459
出版社：Center for Academic Publications Japan
摘要：Utilization and requirement of mixed protein in the con-ventional Japanese diet and the obligatory integumental and micellaneous nitrogen losses were measured in female subjects. Twelve female students aged 18 to 24 years were given conventional low-protein diets at N intake levels of 50, 70, and 90mg/kg/day for 10 days. Constituents of the diets corresponded to those of average intake of the Japanese in recent years (1982). N balances were estimated and regression equations between N intake ( X ) and N balance ( Y ) were calculated by the multiple level-constant variation method. The equation was Y =0.426X-40.0 ( n =36, γ=0.615, p <0.01) and the intersection of the regression line with zero nitrogen balance was 93.9±14.3mgN/kg/day. The mean digestibility was 92.2±4.7%. In another experimental group, nitrogen losses due to hair, nails, and menstruation in ten Japanese women were 0.624 ±0.1.72, 0.020±0.005, and 1.76±0.68 mg/kg/day, respectively. In a third experi-mental group, mean of the integumental N losses was 2.8mg/kg/day in both the subjects given a low-protein diet (19 women) and an ordinary-protein diet (4 women). It increased to 12.7mg N/kg/day when subjects exercised in summer (4 subjects). The protein requirement in the conventional Japanese diet estimated as the sum of the mean requirement of dietary protein and obligatory dermal and miscellaneous nitrogen losses in Japanese women was 99.1mg N/kg/day or 0.62g protein/kg/day. The net protein utilization (NPU) of the proteins at the N intake level for N equilibrium was estimated as 48.
关键词：protein requirement;net protein utilization (NPU);dietary protein;Japanese meal;dermal and miscellaneous N losses;female adults
