Understanding the mechanisms involved in exercise-induced appetite suppression

食欲调节涉及下丘脑中食欲刺激和食欲抑制激素的整合。虽然饮食会影响这些激素，但我的NSERC研究计划的长期目标是了解运动如何影响人类的这些外周信号。使用综合方法，其中运动和营养用于改变食欲调节并研究关键外周食欲信号的影响（即，酰化生长激素释放肽，PYY，GLP-1），我们正在推进对能量摄入调节，代谢和营养领域的理解。我们有四个短期目标，将在未来五年内解决：1）明确乳酸在食欲调节中的作用2）探索血糖和胰岛素在食欲调节中的潜在作用3）检查交感神经系统（SNS）在食欲调节中的潜在作用4）阐明卵巢激素在食欲调节中的任何作用-我们强调了影响这些激素的几种潜在机制，如血流、缺氧和炎症（Hazell et al. 2016，Appetite）。我们的工作来自我最初的NSERC发现资助，表明急性运动后食欲以强度依赖性方式受到抑制，这种运动诱导的食欲抑制可能受到血液乳酸积累的调节。然而，我们不能排除其他运动相关因素在食欲调节中的作用，如血糖和胰岛素，因为有强有力的动物实验支持它们的作用。我们还将研究SNS的作用，这是最假设的机制，但没有数据支持。最后，我们建议继续关注卵巢激素在食欲中的作用，因为女性被排除在这类研究之外，因为月经周期中的激素波动被视为一个不方便的混杂因素，而不是食欲的相关生理调节剂。拟定的工作将使用连续抽血（即，运动前和运动后）几个小时以建立效果的时间过程。所有样本量都是基于检测从先前的工作中确定的男性和女性关键食欲激素的显著差异。将分析特定的食欲调节激素，如酰化生长激素释放肽、PYY、GLP-1和潜在的生理介质（乳酸盐、葡萄糖/胰岛素、SNS儿茶酚胺、卵巢激素）。所有研究都使用急性运动或营养（即，补充）在独特的研究设计，以进一步了解运动在食欲调节中的作用。 影响-重要的是要探索和了解运动如何抑制食欲。提高我们对食欲调节的理解是机械研究应用的一个组成部分，该研究的重点是如何通过锻炼来抑制食欲，从而改善身体成分和整体健康。

Appetite regulation involves the integration of appetite-stimulating and appetite-inhibiting hormones in the hypothalamus. While eating is known to influence these hormones, the long-term objective of my NSERC research program is to understand how exercise affects these peripheral signals in humans. Using an integrative approach where exercise and nutrition are used to alter appetite regulation and study the effects of key peripheral appetite signals (i.e., acylated ghrelin, PYY, GLP-1), we are advancing understanding in the fields of energy intake regulation, metabolism, and nutrition. We have four short-term objectives that will be addressed over the next 5 years: 1)Clearly identify the role of lactate in appetite regulation 2)Explore the potential role of blood glucose and insulin in appetite regulation 3)Examine the potential role of the sympathetic nervous system (SNS) in appetite regulation 4)Elucidate any role of ovarian hormones in appetite-regulation We highlighted several potential mechanisms affecting these hormones such as blood flow, hypoxia, and inflammation (Hazell et al. 2016, Appetite). Our work derived from my initial NSERC Discovery Grant suggests appetite is suppressed after acute exercise in an intensity-dependent manner and this exercise-induced appetite suppression may be modulated by blood lactate accumulation. However, we cannot rule out the contributions of other exercise-related factors in appetite regulation such as blood glucose and insulin as there is strong animal work to support their role. We will also examine the role of the SNS, which is the most-hypothesized mechanism to be involved but with no data to support. Finally, we propose continuing our focus on role of ovarian hormones in appetite as females have been excluded from this type of research because hormonal fluctuations across the menstrual cycle have been viewed as an inconvenient confounding factor, rather than a relevant physiological modulator of appetite. The proposed work will be conducted in humans using serial blood draws (i.e., pre- and post-exercise) over several hours to establish a time course of effects. All sample sizes are based on detecting a significant difference in key appetite hormones established from previous work in males and females. Specific appetite-regulating hormones such as acylated ghrelin, PYY, GLP-1 and potential physiological mediators (lactate, glucose/insulin, SNS catecholamines, ovarian hormones) will be analyzed. All studies use acute exercise or nutrition (i.e., supplement) in unique study designs to further our understanding of the role of exercise in appetite regulation. IMPACT - It is important to explore and understand how exercise suppresses appetite. Improving our understanding appetite regulation is integral in the application of mechanistic research focused on how exercise can be structured to suppress appetite, and therefore improve body composition and overall health.