Inclusion Criteria:  Individuals aged 40 - 60 years old Overweight (BMI ≥ 23kg/m2) or obese (BMI ≥ 25 kg/m2) With at least one blood test result showing IGT (7.8-11.0 mmol/L after a two-hour glucose tolerance test), IFG (fasting glucose 5.6 - 6.9 mmol/L) or impaired HbA1c 5.7% - 6.4% Owns a smartphone Able to read Chinese and speak Cantonese.  Exclusion Criteria:  With current or clinical history of T2DM, or with co-morbid conditions that may limit participation in the study, such as recent history of an acute cardiovascular event, uncontrolled hypertension, cancer or major psychiatric or cognitive problems Already participating in a weight loss programme Receiving drug treatment for pre-diabetes or long-term use of medicines known to influence glucose metabolism (e.g. corticosteroids)