John G. Thomas - US grants

DESCRIPTION (provided by applicant): Overweight and obesity are major health problems, affecting over two-thirds of US adults. Standard behavioral treatments (SBT), which are the gold standard for mild and moderate obesity, have been adapted for Internet delivery to facilitate dissemination, reduce cost, and overcome barriers to treatment. However, the weight losses obtained via Internet-delivered treatment are about half the size of those obtained via in-person treatment, likely because of the lack of (1) hands-on training in behavioral weight control strategies, and (2) support and guidance from group leaders and peers, both of which are hallmarks of traditional in-person SBT. The goal of this application is to improve Internet-delivered behavioral obesity treatments by developing a virtual reality (VR) system that can be integrated into existing Internet weight control programs, such as those developed by our research team. The VR system will provide the experience of learning and implementing behavioral weight control strategies in controlled virtual settings with the support of a virtual coach that demonstrates skills and provides encouragement. The ability to see skills being used appropriately, practice skills repeatedly, and receive reinforcement, will improve the learning process that takes place. The VR system will: (a) increase awareness of barriers to weight control behaviors, (b) teach skills to cope with these barriers, (c) build confidence using these skills, and (d) increase commitment to using these skills in real-world situations. The design of the VR System is based on Social Cognitive Theory, which states that health behaviors are learned by observing and imitating peers and role models, and by receiving social reinforcement. The VR system we propose to develop will consist of two parts: (a) the VR software engine that is the core, or architecture, of the program, which makes it possible to create interactive VR environments for delivery via the Internet, increases scalability, and improves cost effectiveness of future content development, and (b) the behavioral intervention content, which is delivered via the software engine, and consists of a series of interactive vignettes (i.e., modules) that will teach and reinforce behavioral weight control strategies. The VR system will be designed for integration with existing Internet-delivered behavioral weight loss programs. Typically these programs provide users with a weekly weight loss lessons on topics such as eating in social situations and building environmental cues for physical activity. The VR vignettes will be designed to complement these topics. The vignettes will be set in fully rendered computer generated environments with virtual actors, and will allow the user to fully experience learning and implementing behavioral weight control strategies. A virtual coach will lead the user through each vignette, teach the user behavioral weight control strategies, and help the user cope with any consequences of using behavioral weight control strategies. In Phase I of this project, we will develop the VR software engine and one vignette focused on social eating situations that will be used to conduct initial feasibility and efficacy testing. In Phase II, we plan to develop additional vignettes and test the complete VR system in a RCT of Internet-delivered obesity treatment. (End of Abstract)

DESCRIPTION (provided by applicant): Overweight and obesity are major health problems, affecting over two-thirds of US adults. Commercially available Internet-based weight loss programs are currently used by millions of overweight/obese individuals in the U.S, but weight losses are often poor, likely because these products on the whole do not incorporate empirically validated behavioral weight loss strategies that have been researched for over 40 years. Similarly, the weight losses obtained via research-based online weight loss programs are about half the size of those obtained via in-person treatment, likely because of the lack of (1) hands-on training in behavioral weight control strategies, and (2) support and guidance from group leaders and peers, both of which are hallmarks of traditional in-person treatment. The goal of this application is to improve commercial Internet -delivered behavioral obesity treatments by developing a virtual reality (VR) system that can be integrated into existing Internet weight control programs, such as Weight Watchers Online. The VR system will allow users to experience learning, implementing, and mastering behavioral weight control strategies in controlled virtual settings with the support of a culturally sensitive virtual coach. The VR system will: (a) increase awareness of barriers to weight control behaviors, (b) teach skills to cope with these barriers, (c) build confidence using these skills, and (d) increase commitment to using these skills in real-world situations. The design of the VR System is based on Social Cognitive Theory, which states that health behaviors are learned by observing and imitating peers and role models, and by receiving social reinforcement. A Phase I application (1R41HL114046- 01) was recently completed successfully by the applicants, in which a prototype VR weight loss intervention, designed for integration with existing Internet-delivered behavioral weight loss programs, was developed and pilot tested with a single VR vignette focused on social eating situations. A virtual coach will was used to lead the user through the vignette, teach the user behavioral weight control strategies, and help the user cope with any consequences of using behavioral weight control strategies. This interactive social eating vignette produced statistically significant improvements in self-reported difficulty controlling eating in social situations, and knowledge, confidence, and commitment for using empirically validated skills for controlling eating in social situations. In this Phase II application we propose to refine the socil eating vignette created and tested in Phase I, and develop an additional 3 vignettes pertaining to other challenging situations involving eating, physical activity, and sedentary behavior (i.e., time spent sitting). We will conduct a randomized controlled trial (RCT) with N = 125 participants to test the efficacy of the 4 vignettes for improving weight losses obtained in a popular paid commercial weight loss program (Weight Watchers Online) over 6 months. Upon successful completion of this Phase II project, we will market the VR system with 4 vignettes to providers of commercially available Internet-based weight loss programs such as Weight Watchers, Inc. (see included letter of support).

PROJECT SUMMARY/ABSTRACT Long-term weight control is difficult to achieve and requires permanent changes in eating behavior. Emerging wearable sensor technology enables accurate and objective measurement of ingestive behavior, and real-time analysis of the sensor data paves the way for development of individually tailored and immediately delivered intervention (just-in-time adaptive Intervention; JITAI) to change eating behavior. Grounded in empirically and theoretically supported behavior change strategies for weight control, the proposed project relies on the synergy of wearable sensor technology, machine learning, behavioral science, personalized medicine, and nutrition to deliver and test such JITAIs. We previously developed a wearable sensor, the Automatic Ingestion Monitor (AIM), that automatically and accurately detects eating and characterizes meal microstructure (e.g., eating duration, rate of ingestion). These data can also be used to accurately estimate energy intake. The goals of this project are to: 1) use the AIM to study two common behavioral patterns observed among individuals with overweight/obesity, namely, excessive total daily energy intake (EI) and fast eating rate; 2) define the optimal personalized triggering metrics for two JITAIs targeting these behaviors; and 3) evaluate JITAIs? effects on daily energy intake and targeted behaviors. In fulfillment of these goals, we will first conduct a study to characterize the target eating behaviors, then simulate and define triggering metrics for personalized JITAIs to change targeted eating behaviors and decrease EI. The JITAIs are rooted in self-regulation theory (SRT): setting a behavioral goal and monitoring progress toward that goal, with feedback to reinforce success. To enable the SRT-informed JITAIs, we will first use the AIM to collect data about ingestive behaviors quantified by objective, sensor-measured metrics from 90 adults with overweight/obesity who will wear the device for one week in free living conditions. Second, using the collected dataset, we will: a) analyze individual curves of cumulative daily EI and rate of eating within eating episodes to define triggering parameters for personalized JITAI delivery, and b) numerically simulate JITAI delivery and effects. We will then conduct a second study to evaluate the immediate effect of JITAIs on EI and ingestive behavior in free living participants. We will conduct a within-subjects trial with 128 adults wearing the AIM for 7 weeks. To personalize JITAIs, the AIM will learn individual eating patterns over a 1-week run-in period. Each JITAI will be delivered for two weeks (weeks 2-3 and 5-6) in a randomized crossover design with the resulting daily EI and ingestive behavior compared to baseline and the acceptability of the JITAIs assessed via questionnaire. On washout weeks 4 and 7, participants will continue to wear the AIM (no JITAIs) to assess persistence of intervention effects. The proposed project is the first step in demonstrating that AIM-based JITAIs can alter a variety of eating behaviors associated with excess EI.