Background Increased adoption of off-the-shelf conversational agents (CAs) brings opportunities to integrate therapeutic interventions. Motivational Interviewing (MI) can then be integrated with CAs for cost-effective access to it. MI can be especially beneficial for parents who often have low motivation because of limited time and resources to eat healthy together with their children. Objective We developed a Motivational Interviewing Conversational Agent (MICA) to improve healthy eating in parents who serve as a proxy for health behavior change in their children. Proxy relationships involve a person serving as a catalyst for behavior change in another person. Parents, serving as proxies, can bring about behavior change in their children. Methods We conducted user test sessions of the MICA prototype to understand the perceived acceptability and usefulness of the MICA prototype by parents. A total of 24 parents of young children participated in 2 user test sessions with MICA, approximately 2 weeks apart. After parents’ interaction with the MICA prototype in each user test session, we used qualitative interviews to understand parents’ perceptions and suggestions for improvements in MICA. Results Findings showed participants’ perceived usefulness of MICAs for helping them self-reflect and motivating them to adopt healthier eating habits together with their children. Participants further suggested various ways in which MICA can help them safely manage their children’s eating behaviors and provide customized support for their proxy needs and goals. Conclusions We have discussed how the user experience of CAs can be improved to uniquely offer support to parents who serve as proxies in changing the behavior of their children. We have concluded with implications for a larger context of designing MI-based CAs for supporting proxy relationships for health behavior change.

BACKGROUND Increased adoption of off-the-shelf conversational agents (CAs) brings opportunities to integrate therapeutic interventions. Motivational Interviewing (MI) can then be integrated with CAs for cost-effective access to MI. MI can be especially beneficial for parents who often have low motivation due to limited time and resources to eat healthy together with their children. OBJECTIVE We developed MICA—Motivational Interviewing Conversational Agent to improve healthy eating in parents who serve as a proxy for health behavior change in their children. Proxy relationships involve a person serving as a catalyst for behavior change in another person. Parents, serving as proxies, can bring about a behavior change in their children. METHODS We conducted user test sessions of MICA to understand the perceived acceptability and usefulness of MICA by parents. Twenty-four parents of young children participated in two user test sessions with MICA, approximately two weeks apart. After parents’ interaction with MICA in each user test session, we used qualitative interviews to understand parents’ perceptions and suggestions for improvements in MICA. RESULTS Findings showed participants’ perceived usefulness of MICA for helping them self-reflect and motivating them to adopt healthier eating habits together with their children. Participants further suggested various ways MICA can help them safely manage their children’s eating behaviors and provide customized support for their proxy needs and goals. CONCLUSIONS We discuss how the user experience of CAs can be improved to uniquely offer support to parents who serve as proxies in changing the behavior of their children. We end with implications for a larger context of designing MI-based CAs for supporting proxy relationships for health behavior change.