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

June 25, 2026 updated by: University of North Carolina, Chapel Hill

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

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Brooke T Nezami, PhD
  • Phone Number: 2 919-966-5852
  • Email: bnezami@unc.edu

Study Contact Backup

Study Locations

  • United States
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27514
        • University of North Carolina at Chapel Hill

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Core Intervention
Participants receive the standard AGILE behavioral weight loss intervention via the study smartphone application.
Behavioral: AGILE Intervention

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.
Experimental: Core Intervention with Chatbot
Participants receive the standard AGILE behavioral weight loss intervention via the study smartphone application plus a chatbot integrated into the app.
Behavioral: AGILE Intervention

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.

Behavioral: Chatbot

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.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
up to 12 weeks
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.
up to 12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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.
12 weeks
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.
12 weeks
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
Baseline, Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of North Carolina, Chapel Hill

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
UNC Gillings School of Global Public Health

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Brooke T Nezami, PhD, University of North Carolina, Chapel Hill

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 23, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 21, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 28, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 9, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 9, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 16, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 26, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 25, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 25-1638

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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