Evira is a digital support system newly developed for treatment of childhood obesity. Through daily weighings at home using a special scale together with a message function in the Evira application, enabling fast and easy communication with the clinic, parents and the clinicians can easily follow the child's weight development. The purpose of this randomized controlled study is to evaluate the effect of adding Evira to the already locally used life-style treatment of childhood obesity.

Obesity in childhood is a global public health problem which continues to increase. It is associated with type 2 diabetes, high blood pressure, certain types of cancer, decreased psychosocial health and early mortality, among many other short- and long-term consequences. It is estimated that families of children with obesity need at least 26 hours of contact with the health care per year to make it possible for the children to reach a clinically relevant reduction in degree of obesity. Such visit frequency is difficult to carry out due to its cost for society and places great demands on families.

A digital support system named Evira has newly been developed and is based on four cornerstones; a) daily self-monitoring of weight, b) a mobile app used by parents to easily follow weight development, c) a website on which clinicians view the same data as parents do and d) communication between clinicians and parents by text messages through the website and the mobile app. Hence, Evira enables close follow-up of treatment results and continuous communication between the healthcare and the families.

The overall aim is to evaluate the effects of adding Evira, a digital support system for childhood obesity treatment and accompanying treatment manual, to the already locally used life-style treatment.

Boys and girls aged 4-17 years old with obesity will be asked for participation. All patient who fulfills the inclusion criteria and have signed the informed consent form will be included and randomized into the study. Randomization means that the patient can either be randomized to intervention (Evira Care) or control (Standard Lifestyle Care) group.

The study duration is 12 months. The Intervention group will receive Evira support (Evira Care) in combination with local standard treatment (Standard Lifestyle Care). During the first 2-4 weeks, they will receive information about the system and how to utilize the daily weighings and communication system. The families will be informed about possible lifestyle changes that may be effective. Furthermore, they will be informed that they are supposed to do lifestyle changes primarily regarding energy intake that they do consider feasible in their specific living situations. Within four weeks after randomization, the families will get one or two scales, depending on the family situation. The parent's will also have the mobile app installed in their smart phones and, depending on the age of the child, in the child's phone as well. The individual weight loss target curve for the first three months of treatment will be installed in the database and presented in the application. The control group will receive Standard Lifestyle Care without any restriction in visits or clinical support.

The following clinical investigations will be completed in both groups: 1) Physical examination including puberty, cardio-respiratory, thyroid status, skin (e.g. acanthosis nigricans) and abdominal examinations, and 2) Weight, height, and blood pressure. Blood sampling in accordance with local routine can be reported at any time-point.

In addition to the clinical investigation, all participants will be asked to answer questionnaires including quality of life, eating disorders, and treatment satisfaction. Background information and negative side effects will be reported in the electronic case report form (e-crf).

Inclusion Criteria:

• Age >4.0 and <17.0 years of age at inclusion
• Obesity defined based on the International Obesity Task Force criteria iso-BMI 30 - 40 kg/m2
• Willingness to participate in an obesity treatment clinical trial
• Family ability to communicate in the language of the country of residence e.g. write and read messages in the mobile application
• Parents having a smart phone and an email address

Exclusion Criteria:

• Morbid obesity defined as iso-BMI>40kg/m2 independently of age
• Endocrine disorders other than well controlled hypothyroidism
• Metabolic disorders of importance for weight control - to be discussed
• Treatment for depression and other psychiatric disorders during the last 6 months before inclusion
• Pharmacological treatment of importance for weight control
• Hypothalamic or monogenic obesity, e.g. syndromes and Mb Down
• Severe neuropsychiatric disorders that could affect study compliance
• Eating disorders requiring therapy during the last six months before inclusion or observed at the inclusion screening.

Anonymized data for the main outcome will be available upon date of scientific publications. To preserve individual case and anonymity, more detailed data and additional variables will be available upon request.

Data will become available upon date of scientific publications or on requests.