This RCT study will evaluate the effect of a lifestyle intervention on overweight or obese patients with type 2 diabetes mellitus. The primary hypothesis is that the mHealth-based intensive lifestyle intervention is sufficient to achieve weight loss and maintain glycated hemoglobin control.

Diabetes mellitus is a chronic systemic metabolic disease caused by the long-term interaction of genetic factors and environmental factors. It is characterized by an increase in plasma glucose levels and is mainly due to metabolic disorders in glucose, fat, and protein caused by insufficient insulin secretion and/or dysfunction in the body, which affects normal physiological activities. As of 2019, 463 million people are suffering from diabetes in the world, of which 90% to 95% have type 2 diabetes mellitus (T2DM), with an average of 1 patient in every 11 adults (aged 20-79). The number of patients with T2DM will jump to 700 million by 2045. There is a close relationship between T2DM and overweight and obesity. The prevalence of diabetes in overweight and obese people in China was 12.8% and 18.5%, respectively. Among T2DM patients, the proportions of overweight and obesity were 41% and 24.3%, respectively.The two kinds of diseases share a common key pathophysiological mechanism, which will have a devastating long-term impact on patients' health and bring serious disease and economic burden to the family. Given the various harms, it is urgent to carry out relevant intervention research and formulate effective intervention strategies. With the development of artificial intelligence technology, the combination of mHealth and multidisciplinary lifestyle intervention may become an efficient and easy-to-popularize management mode for the prevention and treatment of T2DM with obesity.

Given the relative lack of high-quality interventions for T2DM overweight/obesity, the investigators designed a randomized controlled trial to assess the effectiveness of a multicomponent intervention in Ningbo First Hospital. This study plans to adopt the online and offline combination method based on mHealth technology to carry out lifestyle intervention aimed at formulating a set of feasible and effective intervention strategies.

The study aims to identify: 1) whether the mHealth-based intensive lifestyle intervention will be effective for weight and glycated hemoglobin management to reverse or slow down the disease process among T2DM patients with overweight/obesity; 2) whether the intervention will be beneficial for improving biochemical indicators, body composition indicators, and exercise capacity among T2DM patients with overweight/obesity.

Inclusion Criteria:

1. Meet the WHO diagnostic criteria for type 2 diabetes;
2. The duration of diabetes is less than 5 years;
3. HbA1c was between 6.5-11% in recent 3 months;
4. 18-65 years old;
5. 24kg/m2≤BMI#40kg/m2;
6. Weight loss within the past 3 months did not exceed 5% of initial weight;
7. Currently using a smartphone;
8. Voluntary participation.

Exclusion Criteria:

1. Pregnant or lactating woman, or planning a pregnancy within 6 months after recruitment;
2. Uncontrolled hypertension (resting blood pressure ≥ 160/100mmHg);
3. Treatment with insulin;
4. Acute complications of diabetes (diabetic ketoacidosis, hyperosmolar state, infection. etc) have occurred within the past 3 months, or one or more severe chronic complications of diabetes have existed, such as severe cardiovascular or cerebrovascular pathology (angina pectoris, myocardial infarction, grade III-IV heart failure, severe arrhythmia, transient cerebral ischemic attack, stroke, etc.), massive proteinuria (urinary albumin/creatinine ratio ≥300 mg/g), and severe diabetic foot, severe neuropathy, blurred vision.
5. Currently using weight-reducing products such as orlistat, or other medications that can significantly affect weight such as diuretics and hormones;
6. Severe cardiovascular and cerebrovascular diseases, respiratory diseases, hepatic and renal insufficiency, malignant tumors and other chronic consumptive diseases, active infections, and surgical history involving important organs within 3 months;
7. Contraindications to physical activity;
8. The presence of mental or cognitive impairment;
9. Current participation in other clinical trial projects;
10. Having the same family member involved in the research.