Consistency in Individual Differences in Energy Intake Following Acute Exercise

项目摘要/摘要：有证据表明，体育活动（PA）可以降低几种主要癌症的风险。一种提出的减少癌症发生的机制是通过PA对能量平衡的影响，特别是通过产生能量赤字。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，急性研究表明，一些人在运动后显著增加他们的能量摄入（EI），并保持正的能量平衡（“代偿者”），而另一些人在运动后减少或轻微增加EI，并留下能量赤字（“非代偿者”）。运动后的补偿性饮食行为可能会破坏运动控制体重和预防癌症的效果。因此，研究者已经讨论了确定“补偿者”和“非补偿者”行为表型的重要性，并且已经开始朝着这个方向努力。然而，对这一未来研究路径的一个担忧是，我们目前不知道个人对运动的情商反应是否随着时间的推移而保持一致。也就是说，那些在运动后吃得更多的人在运动后总是吃得更多吗？因此，本研究的主要目的是确定一个人对运动的急性EI反应是否随时间保持一致。我们建议检查30名超重/肥胖女性，每个人将参加3对测试，每对测试包括运动（30分钟中等强度步行）和休息（30分钟坐着）测试日，间隔48-96小时。能量摄入将在运动/休息后1小时的自助餐中测量。在完成3对测试会话中的每对之后，将计算每对EI （EIdiff = EIex - EIrest）的平均差异，并将使用类内相关性来检查EIdiff在个体内是否随时间一致。对运动对急性EI反应的一致性的检查可以帮助形成下一系列关于运动对能量平衡影响的研究。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，即个人对慢性运动的反应（即体重减轻与体重增加）是否可以从一对测试的EI反应中预测出来。也就是说，如果一个人体重增加

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.