Is long-term maintenance worth the wait? Using real time data capture to examine delayed discounting as a putative target of physical activity adherence in weight loss maintenance interventions

减肥维持（WLM）是体重管理的主要挑战。虽然大多数人谁 减肥打算保持他们的体重，在遵守行为建议方面的衰退是常见的， 导致体重反弹。行为WLM干预可以帮助维持健康的生活方式，但应对 治疗是可变的。此外，干预措施发挥其作用的作用机制并不 这阻碍了更有效的治疗方法的发展。推进 行为改变的科学，需要研究来确定WLM参与的假定目标 干预和驱动行为改变。时间自我调节理论（TST）认为， 意图导致的行为在很大程度上取决于自我调节能力（即，执行功能）。 与WLM特别相关的是延迟贴现（DD）的认知结构，或贴现倾向 更大的未来奖励（体重管理）有利于更小的即时奖励（例如，一个愉快的 活动）。实验和临床研究表明，DD有助于行为决策- 但尚未在WLM的背景下进行探索。此外，本发明还 TST假定环境的调节作用，使得当参与行为的成本（例如， 在恶劣天气下锻炼）比它的好处（健康改善）更接近，自我调节 像DD这样的结构将是行为的更强的决定因素。这项研究的目的是测试 是否如TST预测的那样，延迟折扣介导了对体力活动的坚持（PA） WLM干预措施的建议，以及环境因素是否缓和这种关系。PA是 焦点的行为，因为它是WLM成功的一个强大的预测因素，可以在自然界中客观地测量。 环境这项工作是新颖的，因为它将使用实验医学方法来确定是否 DD由行为WLM干预参与，该干预通过使用情景未来明确针对DD 思维，一个可视化的程序，显示在放大长期奖励的价值，从而承诺， 降低DD。DD的参与和体力活动之间的时间关联将被检查， 真实的实时数据采集方法（生态瞬时评估和加速度计）， 了解假定目标（DD）如何/何时参与WLM治疗，以及这是否 参与预测持续的PA行为改变。这种密集的人内纵向设计也将 允许探索环境因素如何调节延迟折扣-身体活动联系， 为未来的减肥维持及时适应性干预奠定了基础。

Weight loss maintenance (WLM) is the major challenge in weight management. While most individuals who lose weight intend to keep their weight off, decay in adherence to behavioral recommendations is common, leading to weight regain. Behavioral WLM interventions can help sustain healthy lifestyles but response to treatment is variable. Moreover, the mechanisms of action by which interventions exert their effects are not clearly elucidated, which has thwarted the development of more efficacious treatment approaches. To advance the science of behavior change, research is needed to identify putative targets that are engaged by WLM interventions and that drive behavior change. Temporal Self-Regulation Theory (TST) posits that whether intentions lead to behavior depends, in large part, on self-regulatory capacity (i.e., executive function). Particularly relevant to WLM is the cognitive construct of delayed discounting (DD), or the tendency to discount a larger future reward (weight management) in favor of smaller immediate rewards (e.g., a pleasurable sedentary activity). Experimental and clinical research suggests that DD is instrumental in behavioral decision- making and predictive of health behavior change but has yet to be explored in the context of WLM. Further, TST posits a moderating role for the environment such that when the costs of engaging in a behavior (e.g., exercising in bad weather) are more proximal than its benefits (health improvements), self-regulatory constructs such as DD will be a stronger determinant of behavior. The aim of the proposed study is to test whether, as predicted by TST, delayed discounting mediates adherence to physical activity (PA) recommendations in WLM interventions and whether environmental factors moderate this relationship. PA is the behavior of focus as it is a robust predictor of WLM success and can be measured objectively in the natural environment. This work is novel because it will use an experimental medicine approach to establish whether DD is engaged by a behavioral WLM intervention that explicitly targets DD through the use of episodic future thinking, a visualization procedure that shows promise in amplifying the value of long-term rewards, thus reducing DD. Temporal associations between engagement of DD and physical activity will be examined with real time data capture methods (Ecological Momentary Assessment and accelerometry) providing a nuanced understanding of how/when the putative target (DD) is in engaged in WLM treatment and whether this engagement predicts sustained PA behavior change. This intensive within-person longitudinal design will also allow for an exploration of how environmental factors moderate the delayed discounting-physical activity link, setting the stage for a future just-in-time adaptive intervention for weight loss maintenance.