EFFECT OF DIET-INDUCED WEIGHT LOSS ON PYY LEVELS: A PILOT STUDY

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。肥胖正在成为美国的一个主要健康问题。预计在几年内，肥胖将超过吸烟，成为可预防死亡的主要原因。 研究人员最近发现，肽PYY 3 -36（PYY）通过降低食欲和增加饭后的饱腹感来调节食物摄入。肥胖个体的内源性PYY基线水平显著低于瘦个体。 由于PYY降低食欲，因此假设成功减肥的受试者的餐后PYY浓度高于未减肥的受试者。一些研究报告称，在超重和肥胖的个体中，低碳水化合物饮食比低脂饮食更能减轻体重。也有人提出，饮食组成将影响PYY水平，无论是急性和体重减轻后。一些研究表明，与摄入低脂饮食的受试者相比，摄入低碳水化合物饮食的受试者在减肥计划中的损耗率较低。这种较低的损耗率可能是由于饥饿信号较少。因此，还假设在低碳水化合物饮食上减轻体重的受试者将具有比在低脂肪饮食上减轻体重的受试者更高的PYY水平。 这项研究将分两个阶段进行。第1阶段将评估膳食中的大量营养素组成是否会对肥胖个体的餐后PYY浓度产生急性影响。该研究的第2阶段将评估成功的饮食诱导的体重减轻是否会影响肥胖个体的餐后PYY浓度。

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 becoming a major health issue in the United States. In a few years obesity is predicted to surpass smoking as the primary cause of preventable death. Investigators have recently discovered that the peptide PYY3-36 (PYY) regulates food intake by reducing appetite and increasing a sense of fullness after meals. Obese individuals have substantially lower baseline levels of endogenous PYY than lean individuals. Because PYY reduces appetite, it is hypothesized that postprandial PYY concentrations will be higher in subjects who successfully lose weight compared with those who do not lose weight. Some studies have reported greater weight loss on a low carbohydrate as compared with a low-fat diet in overweight and obese individuals. It is also proposed that dietary composition will influence PYY levels, both acutely and after weight loss. Some studies have suggested that attrition rates in weight loss programs are lower in subjects who ingest low carbohydrate diets compared with subjects who ingest low fat diets. This lower attrition rate may be due to fewer hunger signals. Therefore, it is also hypothesized that subjects who lose weight on a low carbohydrate diet will have higher levels of PYY than subjects who lose weight on a low fat diet. This study will be conducted in two phases. Phase 1 will evaluate whether the macronutrient composition of meals affects postprandial PYY concentrations in obese individuals acutely. Phase 2 of the study will evaluate whether successful diet-induced weight loss affects postprandial PYY concentrations in obese individuals.