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

Inclusion Criteria: 1. Hong Kong residents aged ≥18 years; 2. able to read and communicate in Chinese; 3. own a smartphone with internet access; 4. have good mobility alone without gait aid; 5. body mass index ≥ 23.0; 6. 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 Exclusion Criteria: 1. 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; 2. currently receiving treatment for any cancer (active cancer patients) or cancer survivor of any GI cancers (e.g. colorectal cancer, stomach cancer); 3. lactating, pregnant or planning for pregnancy in the coming 6 months; 4. have current diagnosis of psychiatric disorder; 5. have previous diagnosis of eating disorder; 6. have diagnoses of gastrointestinal conditions (e.g. Irritable Bowel Syndrome, Ulcerative Colitis, Crohn's Disease, Coeliac Disease); 7. currently receiving intensive diet or exercise treatment; 8. 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).