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Active, Not Recruiting

NCT Number: NCT07534254

Piloting a Generative Artificial Intelligence Chatbot in a Mobile Weight Loss Program

The goal of this study is to learn if integrating a chatbot into an existing 12-week smartphone-delivered behavioral weight loss program is feasible and effective for weight loss among young adults. Researchers will compare a standard behavioral weight loss program for young adults that delivers 1-2 brief messages per day (AGILE) to the same program with a chatbot that offers additional behavior change support integrated into the app (AGILE + Chatbot) to determine if the program with the chatbot is feasible, acceptable to participants, and improves program engagement and weight change compared to AGILE alone.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Overweight and/or Obesity Body Weight Body Weight Changes Pathological Conditions, Signs and Symptoms Signs and Symptoms Weight Loss

Age range

18 year–39 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of North Carolina at Chapel Hill

Chapel Hill, North Carolina, 27514, United States

About this study

At baseline, 20 young adults, ages 18-39, with overweight or obesity, will be randomized to either the AGILE or AGILE + Chatbot group. Participants in both groups will receive a 12-week mobile behavioral weight loss intervention (AGILE) delivered via the study smartphone application. The weight loss intervention includes weekly evidence-based lessons; personalized goals; self-monitoring of diet, activity, and weight; weekly tailored feedback on progress; and brief, tailored messages 1-2 times per day displayed in the study smartphone app. Participants in the AGILE group will receive no additional program features. Participants in the AGILE + Chatbot group will have a version of the smartphone app with an integrated chatbot. The chatbot will be available for brief conversations 1-2 times per day. Assessments will occur at baseline and 12 weeks.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • body mass index (BMI) of 25-45 kg/m^2
  • English-speaking and writing
  • own an iPhone with a data plan
  • willing to be randomized to either treatment group

Exclusion criteria

  • Type 1 diabetes or currently receiving medical treatment for Type 2 diabetes
  • Other health problems which may influence the ability to walk for physical activity or be associated with unintentional weight change, including tuberculosis, currently receiving cancer treatment, or history of a heart attack or stroke
  • Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q; items 1-4), or report any other reason not able to walk for physical activity
  • Lost 10 or more pounds (and kept it off) in the last 6 months
  • Currently taking weight loss medications
  • History of weight loss surgery or planning weight loss surgery in the next 4 months
  • Report a past diagnosis of, or receiving treatment for, a DSM-5-TR (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision) eating disorder (anorexia nervosa or bulimia nervosa)
  • Currently pregnant or planning to become pregnant within the next 4 months
  • Health or psychological diagnoses that preclude participation in a prescribed dietary and exercise program, including history of or diagnosis of schizophrenia or bipolar disorder, hospitalization for a psychiatric diagnosis in the past year, current diagnosis of alcohol or substance abuse
  • Another member of the household is a participant or staff member on this trial
  • Currently participating in a weight loss, nutrition, or physical activity study or program or other study that would interfere with this study
  • Not willing to wear a Fitbit every day
  • Have participated in another study conducted by the UNC Weight Research Program within the past 12 months

Treatment and study plan

AGILE Intervention

Behavioral

12-week behavioral weight loss intervention that includes daily self-monitoring (tracking) of dietary intake, physical activity, and weight; personalized daily goals for dietary intake and physical activity; weekly behavioral lessons in the study app; weekly tailored feedback on goal progress and weight change; and 1-2 intervention messages per day that are tailored based on current diet, activity, and/or weight progress.

Participants receive a Fitbit activity tracker and scale and track their activity and weight in the Fitbit app. Participants use a simplified approach to self-monitoring their dietary intake by tracking 'red' (high calorie) foods in the study's food log smartphone app. This data is used to inform the daily intervention messages and weekly tailored feedback.

Chatbot

Behavioral

The AGILE chatbot operates via a trained generative artificial intelligence large language model and offers additional support to participants for making changes in their dietary and physical activity behaviors.

The chatbot is available for conversation only after a message has been delivered in the AGILE app. Participants can choose to start a conversation or not, and the ability to start a conversation expires at midnight. The chatbot is able to provide evidence-based cognitive behavioral support to participants including, but not limited to: 1) strategies and tips for dietary self-monitoring, physical activity tracking (wearing the Fitbit), and self-weighing; 2) overcoming common barriers to dietary and physical activity goal achievement; 3) general support for remaining engaged in behavior change efforts during the course of the program.

Primary outcomes

  1. Program engagement

    Time frame: up to 12 weeks

    Program engagement is defined as the mean percent of days in which participants accessed the AGILE app.

  2. Chatbot engagement

    Time frame: up to 12 weeks

    Chatbot engagement is defined as the mean percent of days in which participants started a conversation with the chatbot.

Secondary outcomes

  1. Acceptability - Perceived usefulness of chatbot

    Time frame: 12 weeks

    Perceived usefulness (PU) of the chatbot is measured by the Perceived Usefulness subscale of the Technology Acceptance Model Questionnaire. This subscale includes four items that assess usefulness of the chatbot within the AGILE program that are scored on a Likert scale of 1 = Strongly disagree to 7 = Strongly agree. A composite score is calculated by taking an average of the four items. Higher values on the composite PU score represent a greater perceived usefulness of the chatbot.

  2. Acceptability - Perceived ease of use of chatbot

    Time frame: 12 weeks

    Perceived ease of use (EU) of the chatbot is measured by the Perceived Ease of Use subscale of the Technology Acceptance Model Questionnaire. This subscale includes six items that assess how easy it is to use the chatbot within the AGILE program that are scored on a Likert scale of 1 = Strongly disagree to 7 = Strongly agree. A composite score is calculated by taking an average of the six items. Higher values on the composite EU score represent a greater perceived ease of use of the chatbot.

  3. Percent weight change

    Time frame: Baseline, Week 12

    Percent weight change is defined as weight change from baseline to 12 weeks, calculated as [(weight at 12 weeks - baseline weight) / baseline weight] × 100

Sponsors and collaborators

Lead sponsor

University of North Carolina, Chapel Hill

Other

Collaborators

  • UNC Gillings School of Global Public Health

Registry information

Official study title

Leveraging Generative Artificial Intelligence in Mobile Health Promotion Programs: A Use Case for Enhancing Tailored Messaging and Engagement in a Mobile Healthy Weight Program

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Apr 16, 2026
Registry last updated
Jun 26, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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