DIETARY PROTEIN AND BODY COMPOSITION IN OLDER WOMEN

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。据推测，能量和/或蛋白质营养不良是导致与年龄相关的肌肉量减少和随后的身体功能丧失的一个因素。即使RDA对于体重稳定的老年人来说是足够的，在减肥和体重循环的背景下，相对较低的膳食蛋白质摄入量也可能导致肌肉减少症。因此，在热量水平下可以提供足够蛋白质的饮食，在达到减肥目的时可能会缺乏蛋白质。我们建议进行一项试点研究，这将使我们能够收集初步数据来计算精确的样本量，以便设计一项随机对照临床试验，以测试老年、超重和肥胖女性在摄入两倍于RDA的蛋白质后，是否会减轻标准蛋白质低热量饮食导致的瘦体重损失。主要结果将是瘦质量损失相对于总重量损失的量。我们还将评估与肌肉质量、心血管危险因素和身体功能相关的次要结果，以深入了解蛋白质摄入在调节这些因素中的作用。在试点研究中，我们计划招募12名年龄较大、超重或肥胖的女性，并让她们进行低热量饮食。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. It has been hypothesized that energy and/or protein malnutrition is a contributing factor to age-related loss of muscle mass and subsequent loss of physical function. Even if the RDA is adequate for weight stable older adults, relatively low dietary protein intakes might contribute to sarcopenia in the context of weight loss and weight cycling. Thus, diets that may provide adequate protein when consumed at eucaloric levels may be protein deficient when consumed at amounts to achieve weight loss. We propose to conduct a pilot study, which will allow us to gather preliminary data to calculate accurate sample sizes for the design of a randomized controlled clinical trial to test whether a protein intake twice the RDA will attenuate the loss of lean body mass seen in response to a standard protein hypocaloric diet in older, overweight and obese women. The primary outcome will be the relative amount of lean mass lost in relation to the total amount of weight lost. We also will assess secondary outcomes related to muscle quality, cardiovascular risk factors, and physical function to gather insight into the role of protein intake in modulating these factors. For the pilot study we plan to enroll 12 older, overweight or obese women and place them on a hypocaloric diet.