Bariatric surgery is the only treatment with long standing effect of morbid obesity. The key elements to success are the patient-selection, an experienced bariatric team and a completed follow-up program. Follow-up programs can consist of, for example, providing social support in support groups, teaching psychological skills, such as coping with the body change or teaching self-regulation of body weight. Furthermore, follow-up is important for dietary and sports counselling. The experience of the team members and coaching skills are essential in indicating the suitable procedure if necessary and guide the patients through the process. Various studies showed a significant positive effect of a completed follow-up program after bariatric surgery on maintaining weight loss. There is a burden for this on site provided care as organizational and financial resources are not unlimited. Especially as the follow-up period is an obligatory 5 years or if possible life long. Even if this aftercare is provided, not all patients complete the complete program. Various reasons are possible for an increasing no-show-rate, the loss of enthusiasm for onsite visits could be one of them. Analogue to other chronic diseases, the addition of telehealth could be useful. Telehealth is the delivery of health-related services and information via telecommunications technologies. It encompasses preventative, promotive and curative aspects. Examples are exchanging health services or education via videoconference, transmission of medical data for disease management (remote monitoring) and advice on prevention of diseases and promotion of good health by patient monitoring and follow-up. The participation of eHealth has been investigated and considered useful in the treatment of obesity. In a systematic review self-measured blood pressure monitoring was associated with better control of hypertension at least in the first year. Its value in a bariatric tract has not been investigated. It can be hypothesized that self-control by eHealth could enhance clinical outcome as more weight loss and comorbidity reduction. Long-term realistic goals setting, consistent use of routines and self-monitoring has been proven effective for weight loss maintenance. Patients with higher self-control are more certain regarding their abilities, which cause higher commitment and adherence to the program. This eventually leads to more weight loss. For this purpose an online monitoring program was designed for our Obesity Centre (BePATIENT) to provide preoperative information as well as aids in the post-bariatric phase by self-control wireless devices for registration of biometric outcomes, teleconference opportunities and access to additional information. In a prospective trial the implementation in several degrees is evaluated.

Inclusion Criteria:

1. Completed the questionnaire online
2. Having ongoing access to internet
3. Ability to use a model of mobile device (smartphone or tablet) with any version of the Android or iOS platform
4. A body mass index above 40 kg/m2 or above 35 kg/m2 with related comorbidity (hypertension, diabetes type 2, hyperlipidaemia, obstructive sleep apnea syndrome or joint arthritis of lower limbs)
5. A primary gastric sleeve or bypass planned
6. Age of 18 years or more
7. Ability to read and write the Dutch language
8. Signed informed consent

Exclusion Criteria:

1. Patients not meeting the inclusion criteria