LOW FAT OR A LOW CARBOHYDRATE DIETARY AND BREAST CANCER RISK

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 肥胖与乳腺癌和许多其他癌症以及心血管疾病、糖尿病、肌肉骨骼疾病和预期寿命缩短的风险有关。 建立有效的饮食和运动行为是控制体重的基础。 预防癌症或减肥的最有效饮食模式是一个有争议的话题，也是科学界各方面争论的主题。 低碳水化合物饮食，如阿特金斯饮食，斯卡斯代尔饮食和区域饮食，主张饮食中总热量的10%至30%来自碳水化合物，总热量的约40%来自蛋白质。 这一数量的蛋白质超过了美国国家科学院建议的蛋白质总热量的10%至35%的范围（食品和营养委员会，2002年）。 低碳水化合物饮食的支持者报告说，高碳水化合物饮食导致较高的血浆胰岛素水平，并促进脂肪生成。 低碳水化合物饮食在普通大众中非常受欢迎，一些短期研究报告称，与富含碳水化合物但低脂肪的饮食相比，低碳水化合物饮食可以更大程度地减少体脂，并更好地维持瘦体重（Farnsworth，2003; Foster，2003）。 然而，只有少数研究减少碳水化合物饮食的持续时间超过六个月，长期体重维持和安全性尚不清楚。 此外，已发表的研究没有利用密集的教育，反馈和监测，这可能是成功的关键决定因素。 因此，我们建议在绝经前妇女中进行一项为期18个月的临床试验，通过强化营养和体力活动咨询来检查诱导和维持体重减轻的疗效。 这项随机II期试验将为所有参与者提供集中监测的干预措施，并将比较低脂饮食干预与蛋白质节约（低碳水化合物）干预。 我们假设热量限制/热量消耗是成功减肥的主要决定因素，而大量营养素分布不太重要，饮食之间没有显着的长期差异。 坚持每一种饮食和身体活动的建议是关键的结果。 这些数据将为未来更大规模的、多机构的、关于体重控制、身体活动和癌症风险因素的随机研究提供必要的可行性数据。 这项研究的次要目标包括一些可能与癌症风险有关的人体测量和生物测量。

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. Obesity is linked to the risk of breast and many other cancers as well as cardiovascular disease, diabetes, musculoskeletal disorders, and reduced life expectancy. Establishing effective behaviors regarding diet and exercise are the foundations of weight control. The most effective dietary pattern for cancer prevention or weight loss is a controversial topic and the subject of great debate among various facets of the scientific community. Low carbohydrate diets such as the Atkins Diet, the Scarsdale Diet and the Zone Diet advocate a diet consisting of between 10% and 30% of total calories from carbohydrates and approximately 40% of total calories from protein. This amount of protein is exceeds the National Academy of Sciences recommended range of between 10 and 35% of total calories from protein (Food and Nutrition Board, 2002). Proponents of low carbohydrate diets report that diets high in carbohydrates result in higher plasma insulin levels and promote lipogenesis. Low carbohydrate diets have been extraordinarily popular among the general public and some short-term studies report greater loss of body fat and greater maintenance of lean body mass when compared with a diet rich in carbohydrate but low in fat (Farnsworth, 2003; Foster, 2003). However, there are only a few studies of reduced carbohydrate diets that are greater than six months in duration and long-term weight maintenance and safety are unknown. Furthermore, the published studies have not utilized intense education, feedback, and monitoring which are likely to be key determinants of success. Thus, we propose an 18-month clinical trial in premenopausal women with intensive combined nutrition and physical activity counseling to examine the efficacy in inducing and maintaining weight loss. This randomized phase II pilot trial will provide intensively monitored intervention to all participants, and will compare a low-fat dietary intervention to a protein-sparing (low carbohydrate) intervention. We hypothesize that calorie-restriction/calorie expenditure is the major determinant of successful weight loss and that macronutrient distribution is less important with no significant long-term difference between diets. Adherence to each diet and physical activity recommendations are key outcomes. These data will provide essential feasibility data for a future larger, multi-institutional, randomized study of weight control, physical activity and cancer risk factors. Secondary goals of the study include a number of anthropometric and biological measures that may be related to cancer risk.