青年女性膳食蛋白质需要量的研究

目的 营养素参考摄入量是营养学研究的基础.根据“2002年中国居民营养与健康状况调查”的数据显示,目前我国正常成年人膳食蛋白质参考摄入量偏高,需要重新评估.方法 9名健康成年女性分别摄入不同蛋白质水平膳食0.75、0.82、0.89、0.97、1.05 g/(kg·d)],每个蛋白质水平持续6d,在第6天时以 13C-亮氨酸作为指示剂进行稳定性同位素代谢实验,计算标记亮氨酸的流量、氧化率和氧化产物产生率等各项动力学参数,通过建立蛋白质摄入量和呼气中13CO2产生率之间的二相回归方程,确定方程的拐点处即为蛋白质的平均需要量.结果 青年女性平均需要量为0.85 g/(kg·d),平均需要量加上2个标准差得到推荐摄入量为0.97 g/(kg·d).结论 结合近年来全国营养调查成年女性的体重代表值推荐我国成年女性的每日蛋白质摄入量为55 g,该推荐量低于我国现行的成年女性蛋白质推荐摄入量.

Study on the dietary protein requirements of young female adults

Objective: Reference intakes of nutrients are the basis for nutritional research. The results of The Nutrition and Health Status Survey of Chinese Residents in 2002 pointed out that dietary reference intakes of protein in healthy adults are overestimated and need to be reevaluated. Methods: 9 healthy female adults received a restricted daily level of protein intake (0.75, 0.82, 0.89, 0.97 and 1.05 g/(kg•d)). Every dietary protein level lasted six days. On the sixth day, take 13C-leucine as a tracer to carry out stable isotope metabolic experiment. The kinetic parameters including leucine flow, oxidation rate and oxidation products production rate were calculated. We applied biphasic linear regression crossover analysis on F13CO2 data and protein intakes. By doing this, we identified a breakpoint at the minimal rate of appearance of 13CO2 expiration, specific to each level of dietary protein. Results: The Estimated Average Requirement (EAR) and the Recommended Nutrient Intake (RNI) of protein for healthy Chinese young female adults were determined to be 0.85 and 0.97 g/(kg•d). Conclusion: According to the reference weight of female adults in recent national nutrition survey, We calculated that the daily protein recommended requirements for female adults is 55g, which is lower than current protein recommended requirements.