An Innovative Care Model Integrating Mobile Health Support to Promote Weight Management in Adults With Overweight or Obesity

NCT06996431 | Enrolling By Invitation

• 1 other identifier: WM
• Study Type: interventional
• Target: 876
• Locations: 1 country
• Sites: 3

Brief Summary

The objective of this clinical trial is to evaluate whether an innovative care model integrating mobile health (mHealth) support improves weight management in adults with overweight or obesity. The primary research questions are: (1) Does the intervention promote weight change at the 6-month follow-up? (2) Does the intervention enhance physical activity and encourage a healthy diet at the 3- and 6-month follow-ups? To address these questions, researchers will compare the intervention group with a control group to measure changes in weight, physical activity, and dietary habits. At baseline, all participants will complete a survey assessing demographics, body weight, height, central obesity, lifestyle, weight loss history, and expectations. The intervention group will receive a weight management program based on Ecological Momentary Assessment (EMA), incorporating risk-stratified health services, with follow- ups at 3 and 6 months. The control group will receive minimal intervention in the form of general health advice, with follow-ups at the same intervals.

Conditions

Overweight or Obesity; Physical Activities; Healthy Diet; Weight Change; Body Fat; Muscle Mass

Keywords

ecological momentary assessment; weight management; mHealth; primary care; stepped-wedge; cluster RCT; risk stratification; nurse-led

Outcome Measures

Primary Outcomes (1)

• Change in weight

  Defined as the change in weight of participants over a specified period, this measurement compares the weight change between the intervention and control groups. Participants' weights will be recorded in kilograms at baseline and at a 6-month follow-up using a calibrated digital scale.

  6-month from baseline

Secondary Outcomes (17)

• Change in weight

  3- and 12-month from baseline

• Proportion of overweight or obesity

  3-, 6- and 12-month follow-up from baseline

• Proportion of participants with ≥5% weight change

  3-, 6- and 12-month follow-up from baseline

• Change in body fat

  3- and 6-month follow-up from baseline

• Change in muscle mass

  3- and 6-month follow-up from baseline

Study Arms (2)

Control group intervention

ACTIVE COMPARATOR

Participants in the control group will receive minimal Intervention. They will not be provided with risk-stratified services.

Behavioral: Minimal Intervention

EMA-based weight management intervention

EXPERIMENTAL

Participants in the intervention group will join an mobile health (mHealth) weight management program integrating ecological momentary assessment (EMA) via a mobile app, post-EMA counseling, and risk-stratified coaching. This program provides real-time monitoring and personalized feedback to improve diet and physical activity.

Behavioral: EMA-based weight management intervention

Interventions

EMA-based weight management intervention BEHAVIORAL

Participants will complete four 7-day EMA sessions, reporting their diet for 3 days and physical activity for 4 days by completing five brief daily mobile app surveys (under 2 minutes each), using a 5-digit case number for privacy. The app automatically retrieves Fitbit data-such as step count, moderate-to-vigorous physical activity (MVPA), sedentary behavior, and heart rate- and sends timely reminders if surveys are missed. Within one week after the first EMA session, participants will attend a nurse- led counseling session using the 5A Model (Assess, Advise, Agree, Assist, Arrange), providing tailored feedback based on EMA and Fitbit data, and addressing barriers to change. This is followed by risk-based coaching from a dietitian and fitness instructor, with individualized diet and exercise plans. Between sessions, participants receive ongoing support, including instant reminder messaging and weekly motivational messages to encourage healthy behaviors.

EMA-based weight management intervention

Minimal Intervention BEHAVIORAL

Participants will not receive risk-stratified services but will be provided with informational leaflets offering general advice on maintaining a healthy diet, regular exercise, smoking cessation, and alcohol cessation.

Control group intervention

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Hong Kong residents aged ≥18 years;
• able to read and communicate in Chinese;
• own a smartphone with internet access;
• have good mobility alone without gait aid;
• body mass index ≥ 23.0;
• and no contraindication for physical activity as evidenced by: If aged \< 70: do not meet any criteria in PAR-Q, or sign declaration of having medical clearance if meet any criteria in PAR-Q; If aged ≥ 70: sign the declaration about conducting physical activity frequently or having medical clearance

You may not qualify if:

• Have a terminal illness (e.g., advanced cancer, dementia, pulmonary, neurological, motor-neuron, and advanced cardiovascular disease) or with a life expectancy of less than 6 months;
• currently receiving treatment for any cancer (active cancer patients) or cancer survivor of any GI cancers (e.g. colorectal cancer, stomach cancer);
• lactating, pregnant or planning for pregnancy in the coming 6 months;
• have current diagnosis of psychiatric disorder;
• have previous diagnosis of eating disorder;
• have diagnoses of gastrointestinal conditions (e.g. Irritable Bowel Syndrome, Ulcerative Colitis, Crohn's Disease, Coeliac Disease);
• currently receiving intensive diet or exercise treatment;
• have clinical obesity (e.g. confirmation of excess body fat plus limitations of day-to-day activities or signs or symptoms of obesity-related organ dysfunction). Examples of obesity-related organ dysfunction include NAFLD with hepatic fibrosis, the cluster of hyperglycaemia, high triglyceride levels, and low HDL cholesterol levels. Examples of limitations of day-to-day activities include significant age-adjusted limitations of mobility and/or other basic ADL (e.g. bathing, dressing, toileting, continence, eating).

Sponsors & Collaborators

• The University of Hong Kong: lead
• The Hong Kong Jockey Club Charities Trust: collaborator

Study Sites (3)

Aberdeen Kaifong Welfare Association

Hong Kong, Hong Kong

Location

Haven of Hope Christian Service

Hong Kong, Hong Kong

Location

Hong Kong Sheng Kung Hui Welfare Council

Hong Kong, Hong Kong

Location

MeSH Terms

Conditions

Overweight; Obesity; Motor Activity; Body Weight Changes

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavior

Study Officials

• Siu Chee Chan Professor

  he University of Hong Kong

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: A stepped-wedge cluster randomized controlled trial will be conducted. This design is considered a type of unidirectional crossover randomized controlled trial (RCT). Stepped-wedge trials evaluate the effect of an intervention implemented at the cluster level. In this design, all clusters initially begin in the control condition. Clusters are then randomized into different sequences, which determine the time point at which each cluster transitions from the control condition to the intervention condition. Once a cluster transitions to the intervention, it remains in that condition for the rest of the study. By the final phase, all clusters, including new participants, will be receiving the intervention.

Study Record Dates

• First Submitted: April 17, 2025
• First Posted: May 30, 2025
• Study Start: February 10, 2025
• Primary Completion (Estimated): December 16, 2026
• Study Completion (Estimated): April 30, 2027
• Last Updated: June 11, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF

Locations

HK (3)