Adaptive responses to overfeeding and weight regain in reduced obese individuals

项目总结/摘要 减肥后体重反弹的持续问题可能是最重要的障碍， 解决当前肥胖流行的问题。减肥后恢复体重的生物动力是由于 部分增加食欲，导致增加能量摄入（EI）和减少能量消耗（EE）， 部分原因是身体活动（PA）消耗的能量变化。这些对体重的生理适应 损失是最相关的饮食不谨慎的事件导致过度喂养（OF）时，减少 肥胖（RO）的人不能以维持减少的能量平衡的方式对正能量平衡状态做出反应。 状态有越来越多的证据表明，RO个人谁行使（RO-Ex）不太可能恢复， 与久坐不动的RO个体（RO-Sed）相比。我们对OF对EI的影响进行了研究， 易肥胖（OP）或抵抗肥胖（OR）的非肥胖个体的EE、PA和脂肪代谢。科目 然后随访5年以测量体重变化。这些研究表明， 夜间脂肪氧化反应和较高水平的中度/剧烈PA后OF与5 年体重增加表明这些因素是体重增加的潜在重要机制。进一步 我们已经表明，饥饿的措施未能抑制与反式脂肪酸的个人和夜间脂肪， 在包括一次运动的一天后，RO-Sed中的氧化减少，但在RO-Ex中保持。我们 现在建议研究EE，EI，PA和脂肪代谢对OF（3%高于基础能量40%）的反应 在肥胖、RO-Sed和RO-Ex男性和女性中， 随后几年。我们假设这些变量中的一个或多个对OF的反应的变化将 与体重反弹有关。这些研究的意义在于，它们将开始澄清 代谢机制的基础上的体重反弹的倾向，在RO个人。创新：The 拟议中的研究将系统地检查对OF的一系列反应，并将它们与 体重增加，同时考虑与体重恢复相关的行为方面。我们相信这些 这些研究将为未来的研究奠定基础，这些研究将研究特定适应性的潜在机制。 与体重反弹直接相关的反应，并有助于设计解决和/或应对 这些过程。

Project Summary/Abstract The persistent problem of weight regain following weight loss is perhaps the most significant barrier to addressing the current obesity epidemic. The biological drive to regain weight following weight loss is due in part to increased appetite leading to increased energy intake (EI) and reductions in energy expenditure (EE) in part due to changes in energy expended in physical activity (PA). These physiological adaptations to weight loss are most relevant during episodes of dietary indiscretion resulting in overfeeding (OF) when reduced obese (RO) people fail to respond to the state of positive energy balance in a way that maintains the reduced state. There is increasing evidence that RO individuals who exercise (RO-Ex) are less likely to regain as compared to RO individuals who are sedentary (RO-Sed). We conducted studies on the effects of OF on EI, EE, PA and fat metabolism in non-obese individuals either prone (OP) or resistant to obesity (OR). Subjects were then followed for 5 years to measure weight change. These studies showed that differences in the response of nocturnal fat oxidation and higher levels of moderate/vigorous PA following OF correlated with 5 year weight gain suggesting that these factors were potentially important mechanisms for weight gain. Further we have shown that measures of hunger fail to suppress with OF in RO individuals and that nocturnal fat oxidation is reduced in RO-Sed but maintained in RO-Ex following a day that included a bout of exercise. We now propose to study the responses of EE, EI, PA and fat metabolism to OF (40% above basal energy for 3 days) in obese, RO-Sed and RO-Ex men and women and correlate these responses to weight change over the subsequent year. We hypothesize that changes in the response of one or more of these variables to OF will correlate with weight regain. The Significance of the studies lies in the fact that they will begin to clarify the metabolic mechanisms that underlie a propensity for weight regain in RO individuals. Innovation: The proposed studies will systematically examine a range of responses to OF and prospectively correlate them with weight gain while taking into account aspects of behavior relevant to weight regain. We believe that these studies will lay a foundation for future studies that will examine the mechanisms underlying specific adaptive responses that directly relate to weight regain and help with the design of strategies to address and/or respond to these processes.