Postprandial glycemic response to 4-week low and high glycemic load diets

描述（由申请人提供）：本申请的总体目标是了解高血糖负荷餐和低血糖负荷餐的餐后代谢反应。很多研究都是关于餐后葡萄糖和胰岛素对不同血糖指数的食物的反应，但在人类研究中测量的大多数其他生物标志物都是在禁食状态下进行的。我们对膳食对生物标志物的影响知之甚少，这些生物标志物可能更直接地参与致癌途径，如胰岛素样生长因子。由于经常吃正餐和零食使许多美国人在醒着的许多时间里处于餐后状态，因此了解膳食对感兴趣的生物标志物的影响是一个重要的研究领域，但尚未得到充分研究。我们建议在一项随机交叉喂养研究中测试20名受试者对低血糖负荷和高血糖负荷膳食的餐后反应。在父母研究中，参与者是自由生活的，但在两个为期四周的时间里，他们从人类营养实验室获得所有的食物和饮料。在一个喂养期间，参与者被给予低糖负荷饮食，在另一个期间给予高糖负荷饮食。空腹血在每个喂养期的开始和结束时抽取。在这项拟议的研究中，参与者将被邀请在每个喂养期结束时多吃两顿饭（早餐和午餐），随后进行8小时的连续抽血，以评估胰岛素、葡萄糖、IGFI、IGFII、IGFBP1、IGFBP3、游离脂肪酸和甘油三酯的餐后反应。我们认为，这项研究有效地利用了现有的控制良好的喂养研究，并将为人类对各种膳食模式的代谢反应提供重要信息。研究特定食物如何影响健康的一种方法是给人们喂食含有已知数量营养物质的食物，并测量血液中的各种标志物。这项研究的目的是比较低血糖或高血糖食物与各种生物标志物的关系，这些生物标志物与各种慢性疾病（如癌症）有关。参加随机交叉喂养研究的志愿者将被要求多吃两顿饭；我们将在餐后8小时内通过测量血液中的生物标志物来监测餐后反应。

DESCRIPTION (provided by applicant): The overall goal of this application is to understand the postprandial metabolic response to high vs. low glycemic load meals. Much research has been done on postprandial responses of glucose and insulin to acute feeding of individual foods of varying glycemic index, but most other biomarkers measured in human studies are done in the fasting state. Very little is known about meal effects on biomarkers that may be more directly in the carcinogenesis pathway, such as the insulin-like growth factors. Because frequent eating of meals and snacks places many Americans in the postprandial state for many of their waking hours, understanding meal effects on biomarkers of interest is an important, but understudied, area of research. We propose to test postprandial responses to low- and high-glycemic load meals in 20 individuals who are enrolled in a randomized, cross-over feeding study. In the parent study, participants are free-living but receive all food and beverages from a human nutrition laboratory for two four-week periods. During one feeding period participants are given a low-glycemic load diet and during the other a high glycemic load diet. Fasting bloods are drawn at the beginning and end of each feeding period. For this proposed study, participants will be invited to consume two extra meals (breakfast and lunch) at the end of each feeding period followed by eight hours of serial blood draws to assess the protracted postprandial response of insulin, glucose, IGFI, IGFII, IGFBP1, IGFBP3, free fatty acids, and triglycerides. We believe that this proposed study makes efficient use of an existing well-controlled feeding study and will provide important information on the human metabolic response to various meal patterns. Postprandial glycemic response to 4-week low and high glycemic load diets One way to study how specific foods affect health is to feed people meals with known quantities of nutrients and measure various markers in the blood. This study is designed to compare meals that are low- or high- glycemic load with respect to various biomarkers that are known to be related to various chronic diseases such as cancer. Volunteers enrolled in a randomized cross-over feeding study will be asked to eat two additional meals; we will monitor the postprandial responses by measuring biomarkers in the blood for eight hours after the meals.