Obesity affects an increasing proportion of the population and is associated with numerous comorbidities that cause increased morbidity and mortality.

The most effective therapy for morbid obesity is metabolic bariatric surgery. Surgical numbers are increasing worldwide. Before surgery, patients must try to reduce weight conservatively in a multimodal therapy concept. In addition, numerous protocols must be collected and appointments must be organized. Postoperatively, patients are expected to receive lifelong follow-up care, which increasingly overwhelms bariatric centers.

People with overweight and obesity ° I are often left largely alone with the treatment of their disease. There is a considerable gap in care here.

For the care of patients with obesity and empowerment in dealing with their disease, the smart visit app from the company aycan, which is adapted to obesity patients, is to be investigated. This is designed as a pilot project with the primary endpoint of usage and satisfaction (after 3 months, key secondary endpoint after 12 months). A total of 100 patients from 3 groups (postoperative, preoperative, permanent conservative with only overweight/obesity °I) will use the app for 1 year for this purpose.

The prevalence of obesity has been increasing dramatically for decades. The comorbidities are manifold, and the treatment of obesity is a long-term, usually lifelong task. Metabolic-bariatric surgery offers the best results. However, even after bariatric-metabolic surgery, there is a need for lifelong follow-up to ensure the success of therapy and to identify and treat possible complications, nutritional problems or deficiencies in a timely manner.

The treating centers are increasingly overwhelmed by the follow-up care of the numerous patients. At the same time, the guidelines of the professional societies recommend involving the patient in the success of his or her therapy and enabling him or her to play an active role in shaping his or her treatment. An app tailored to the treatment of obese people, which helps both in the self-organization of the patients in complying with the therapy recommendations and in maintaining contact with the center on a permanent basis and making low-threshold contact when necessary, would be a valuable addition to the existing therapy options for patients and centers alike.

Such an app would also have its value in the preoperative patient, especially since a lot of documentation work has to be done by the patient in this phase.

Patients whose obesity is not pronounced enough for a surgical procedure often complete nutritional counseling and exercise at their own expense without receiving support from experts. Here, too, there would be a need to supplement the therapy options with an appropriately coordinated app.

For the care of patients with obesity and empowerment in dealing with their disease, the smart visit app from the company aycan, which is adapted to obesity patients, is to be investigated. This is designed as a pilot project with the primary endpoint of usage and satisfaction (after 3 months, key secondary endpoint after 12 months). A total of 100 patients from 3 groups (postoperative, preoperative, permanent conservative with only overweight/obesity °I) will use the app for 1 year for this purpose.

General inclusion criteria:

• Smartphone available (iOS or Android with sufficient version of the operating system).
• Age >/= 18 years
• Sufficient language skills to answer the questionnaires

Additional group specific inclusion criteria:

Group 1 (bariatric-metabolic surgery):

• Bariatric-metabolic surgery (sleeve gastrectomy, Roux-Y gastric bypass, omega-loop bypass) at least 24 months ago.

Group 2 (multimodal treatment):

• Participation in a full or partial (if primary indication) multimodal approach.

Group 3 (conservative therapy):

• BMI 28-34.9 kg/m2
• No planned bariatric-metabolic surgery
• Desire for conservative weight reduction

Exclusion Criteria:

• current pregnancy