Consistency in Individual Differences in Energy Intake Following Acute Exercise

描述(由申请者提供)：项目摘要/摘要：有证据表明，体力活动(PA)可能会降低患几种主要癌症的风险。一种被提出的减少癌症发生的机制是通过PA对能量平衡的影响，特别是通过创造能量赤字。然而，最近的证据表明，运动对能量平衡的影响存在显著的个体差异，尖锐的研究表明，一些人在运动后显著增加了他们的能量摄入量(EI)，并留下了正能量平衡(“补偿器”)，而另一些人在运动后降低或略有增加EI，导致能量不足(“非补偿器”)。运动后的补偿性饮食行为可能会削弱运动对控制体重和预防癌症的有效性。因此，研究人员讨论了确定“补偿者”和“非补偿者”行为表型的重要性，并已开始朝这个方向努力。然而，对这一未来研究路径的一个担忧是，我们目前不知道一个人对运动的EI反应是否随着时间的推移而一致。也就是说，运动后吃得明显更多的人在一场运动比赛后总是吃得更多吗？因此，这项研究的主要目的是确定一个人对运动的急性EI反应是否随着时间的推移而一致。我们建议检查30名超重/肥胖女性，她们每人将参加3对测试，每对测试由运动(中等强度步行30分钟)和休息(坐着30分钟)组成，测试间隔48-96小时。能量摄入量将通过在运动/休息后1小时提供的临时自助餐来测量。在完成3对测试过程中的每一对之后，将计算来自每一对的EI的平均差异(EIdiff=EIex-EIrest)，并且组内相关性将被美元，以检查EIdiff在个体内是否随着时间的推移而一致。检查运动对急性EI反应的一致性有助于形成下一系列关于运动对能量平衡的影响的研究。如果我们的假设得到支持，并且一个人对运动的急性EI反应是一致的，我们就可以开始研究一个重要的临床问题，即是否可以从一对测试阶段的EI反应预测个人对慢性运动的反应(即体重减轻与体重增加)。也就是说，如果一个人体重增加了 对于运动训练，这是不是由于运动后EI急剧增加所致？ 此外，未来的研究可能会开始检查是否有生理、行为和认知因素可以预测一个人在运动后是否会增加或降低EI。或者，如果我们的假设不被支持，我们的研究结果可以用来支持更大规模的研究，这些研究考察参与者对运动过程的反应是否存在差异(例如，情感、饥饿、疲劳等方面的变化)。有助于运动后较高或较低的EI。 与公众健康相关：运动对控制体重和预防癌症的重要性是有充分证据的；然而，如果运动导致能量摄入增加，运动的有益效果可能看不到。这项研究解决了目前文献中的一个空白，研究了急性运动对能量摄入反应的个体变异性，并检查了这些反应是否随着时间的推移而一致。更好地了解运动和能量摄入之间的相互关系，最终将导致未来的研究，这些研究可以解决为什么一些人在参加运动训练计划时体重增加，另一些人体重减轻的临床重要问题，并有助于制定运动计划，使其对体重和癌症控制产生最大效果。

DESCRIPTION (provided by applicant): Project Summary/Abstract: Evidence suggests that physical activity (PA) may reduce the risk of several major forms of cancer. One proposed mechanism for this reduction in cancer occurrence is through the effect of PA on energy balance, specifically by creating an energy deficit. However, recent evidence suggests that there is marked individual variability in the effect of exercise on energy balance with acute studies demonstrating that some individuals significantly increase their energy intake (EI) post-exercise and are left with a positive energy balance ("compensators") while others decrease or slightly increase EI post-exercise and are left with an energy deficit ("non-compensators"). Engaging in compensatory eating behaviors following exercise could undermine the effectiveness of exercise for weight control and cancer prevention. Consequently, investigators have discussed the importance of determining the behavioral phenotype of "compensators" and "non-compensators" and efforts have already begun in this direction. However, one concern with this future research path is that we currently do not know whether an individual's EI response to exercise is consistent over time. That is, does someone who eats significantly more after exercise always eat that much more after an exercise bout? Therefore, the primary aim of this study is to determine whether one's acute EI response to exercise is consistent over time. We propose to examine 30 overweight/obese women, each of whom will participate in 3 pairs of testing sessions, with each pair consisting of an exercise (30 minutes of moderate-intensity walking) and resting (seated for 30 minutes) testing day, separated by 48-96 hours. Energy intake will be measured using an ad-libitum buffet meal served 1 hour post-exercise/rest. Following the completion of each of the 3 pairs of testing sessions, the mean difference in EI (EIdiff = EIex - EIrest) from each pair will be calculated and an intraclass correlation will be usd to examine whether the EIdiff is consistent within individuals over time. The examination of the consistency in acute EI responses to exercise can help shape the next series of studies on the effect of exercise on energy balance. If our hypothesis is supported and one's acute EI response to exercise is consistent, we can begin to examine the important clinical question of whether individual responses to chronic exercise (i.e., weight loss vs. weight gain) can be predicted from EI responses from 1 pair of testing sessions. That is, if an individual gains weight with exercise training, is this due to repeated increases in EI acutely following an exercise bout? In addition, future studies could begin to examine whether there are physiological, behavioral, and cognitive factors that predict whether an individual will increase or decrease EI post-exercise. Alternately, if our hypothesis is not supported, findings from our study can be used to power larger studies which examine whether differences in participants' responses to an exercise session (e.g., changes in affect, hunger, fatigue, etc.) contribute to higher or lower EI post-exercise. PUBLIC HEALTH RELEVANCE: The importance of exercise for weight control and cancer prevention is well documented; however if exercise results in an increase in energy intake, the beneficial effect of exercise may not be seen. This study addresses a gap in the current literature and examines the individual variability in energy intake responses to acute exercise and also examines whether these responses are consistent over time. A better understanding of the interrelationship between exercise and energy intake will ultimately lead to future studies that can address the clinically significant question of why some individuals gain weight and others lose weight when engaging in exercise training programs and help to develop exercise programs that maximize the effect on body weight and cancer control.