The TECNOB clinical program has a total duration of 13 months and consists of two stepped down phases: in-patient (1 month) and out-patient (the following 12 months). During the in-patient phase, participants undergo an intensive four-week hospital-based and medically-managed program for weight reduction and rehabilitation. Along this period, participants live in a medical hospital-like environment located on a mountain highland and far away from towns and cities. Visits from parents are allowed only in the afternoon. All patients are placed on a hypocaloric nutritionally balanced diet tailored to the individual after consultation with a dietitian (energy intake around 80% of the basal energy expenditure estimated according to the Harris-Benedict equation and a macronutrient composition of about 16% proteins, 25% fat and 59% carbohydrates). Furthermore, they receive nutritional counseling provided by a dietitian, psychological counseling provided by a clinical psychologist and have physical activity training provided by a physiotherapist.
Nutritional rehabilitation program aims to improve and promote change in eating habits and consists of both individual sessions (dietary assessment, evaluation of nutrient intake and adequacy, nutritional status, anthropometric, eating patterns, history of overweight, readiness to adopt change) and group sessions (45 minutes each twice a week) including: information on obesity and related health risks, setting of realistic goals for weight loss, healthy eating in general, general nutrition and core food groups, weight management and behavior change strategies for preventing relapse).
Psychological counseling is provided once a week both individually and in group setting. Individual sessions, lasting 45 minutes each, are mainly based on the cognitive-behavioral approach described by Cooper and Fairburn  and emphasize the techniques of self-monitoring, goal setting, time management, prompting and cueing, problem solving, cognitive restructuring, stress management and relapse prevention. Group sessions ("closed" groups of 5/6 persons), lasting 1 hour each, focus on issues such as motivation, assertiveness, self-esteem, self-efficacy and coping.
Physical activity takes place once a day except for week-end and consists of group programs (20 subjects) based on postural gymnastics, aerobic activity and walks in the open. Inpatients with specific orthopedic complications carry out individual activities planned by physiotherapists and articulated in programs of physical therapy, assisted passive and active mobilization and isokinetic exercise.
Low to moderate weight losses are expected at the end of the in-patient phase, but it is important to note that weight loss is not the primary goal of the in-patient program and each patient is made clear about this point at the very beginning of the treatment. Beyond the medical management of metabolic risk factors for health such as type 2 diabetes, developing a sense of autonomy and competence are the primary purposes of the in-hospital interventions. Patients are afforded the skills and tools for change and are supported in assigning positive values to healthy behaviors and also in aligning them with personal values and lifestyle patterns.
In the last week, just before discharge from hospital, participants are instructed for the out-patient phase of the program. They receive a multisensory armband (SenseWear® Pro2 Armband), an electronic tool that enables automated monitoring of total energy expenditure (calories burned), active energy expenditure, physical activity duration and levels (METs) and sleep/wake states duration. Patients are instructed to wear this device on the back of the upper arm and to record data for 36 hours every two weeks in a free-living context. The Armband holds up to 12 days of continuous data which the outpatients are instructed to download into their personal computer and to transmit online to a web-site specifically designed for data storing. Outpatients are also told that they can review their progress using the InnerView® Software which analyzes and organizes data into graphs and reports. Participants are then instructed to use the TECNOB platform, an interactive web-site developed by TELBIOS S.P.A. http://www.telbios.it. The TECNOB web-platform supports several functions and delivers many utilities, such as questionnaires, an animated food record diary, an agenda and a videoconference virtual room. In the "questionnaires" section, patients fill in the Outcome Questionnaire  and submit data concerning weight and glycated hemoglobin. In the "food record diary" participants submit actual food intake day by day through the selection of food images from a comprehensive visual database provided by METEDA S.P.A. http://www.meteda.it. The same procedure is also possible through a software called METADIETA (Meteda s.p.a.) previously installed on the outpatients' mobile phones before discharge. Through the mobile phones outpatients maintain the contact with the dietitian who regularly sends them SMS containing syntax codes that METADIETA, the software previously installed into the outpatients' mobile phones, uses in order to visually display the food choices (frequency and portions) outpatients have to adhere according to diet prescriptions. By this way, outpatients can keep a food record diary allowing comparisons between current eating and the recommended hypocaloric diet along the whole duration of the program. The "agenda" allows the patients to remember the videoconference appointments with the clinicians and the days when to fill in the questionnaires. Moreover, the patients can use the "memo" space to note down any important event occurred to him/her in the previous week/month. Indeed, some research indicates that changes in behavior (eating and exercise) often follow discrete moments which have been variably described as life events, life crises, teachable moments or epiphanies . Life events can lead to weight loss but also to weight gain and qualitative research shows that it is not the event per se that results in behavior change but the ways in which this event is appraised and interpreted by the individual . The clinical psychologist has thus the opportunity to discuss with the outpatients about the significant events reported in the "memo" space during the videoconference sessions and cognitively reconstruct dysfunctional appraisals in functional ways. Finally, outpatients are instructed to use the videoconference tool. Thanks to this medium, they receive nutritional and cognitive-behavioral tele-counseling with the dietitian and the clinical psychologist who attended the patients inside the hospital. In particular, just after discharge, participants have 6 videoconference contacts with both clinicians along 3 months. From the 3rd to the 6th month sessions are scheduled every 30 days and then even more spaced up to an interval of 60 days. During tele-sessions, clinicians (psychologist and dietitian) test the outpatients' progress, their mood, the maintenance of the "good alimentary and physical activity habits", the loss/increase of weight and ask about critical moments, especially those ones reported on the "memo" web-space. In particular, tele-sessions with the clinical psychologist aim to consolidate strategies and abilities acquired during the in-patient phase, to improve self-esteem and self-efficacy, to support motivation, to prevent relapse and to provide problem-solving and crisis counseling. On the other hand, dietitian assesses adherence and compliance to dietary therapy with a special focus on normal eating behavior, sufficient fluid intake, hunger and fullness regulation, appropriate eating/etiquette (pace and timing of meals), slow rate of eating, and addresses critical points such as plateau in weight loss or lack of readiness to improve dietary habits.
In addition to videoconference, outpatients can further contact clinicians by e-mail. Indeed, each patient is given the possibility to join his clinician beyond the established videoconference contacts in case of urgency or emergency. According to the e-message's content, clinicians choose the most appropriate format for delivering feedback among e-mail or telephone. In order to avoid excessive dependence and to contain costs, a maximum number of 1 not scheduled contact a week is established a priori.
As described, in the outpatient phase of the TECNOB program great relevance is given to the clinicians-patient relationship as an important medium and vehicle of change . After discharge, out-patients begin to experience the autonomy and competence to change they develop during the in-patient phase and inevitably face resistances and barriers. Thanks to videoconferences, out-patients are supported by the clinicians who attended them during the in-hospital phase in exploring resistances and barriers they experience and in finding functional pathways to cope. Furthermore, out-patients are helped to experience mastery in terms of the health behavior change that needs to be engaged.
Participants in the control group will receive the hospital-based treatment and will be asked to respond to the follow-up assessments. No contact will be maintained with them at home and no continuous care will be provided after discharge.
Psychological and behavioral questionnaires
Participants will complete the following questionnaires at entry to the study, at discharge from the hospital and at 3, 6 and 12-month follow-up time points by postal mail, Differently, the Outcome Questionnaire will be administered electronically through the web-platform before each videoconference session with the clinical psychologist.
The Self-Report Habit Index (SRHI) - Italian translation
The SRHI is a measure of the development and strength of habits. It has a stem " [the behavior] is something that..." followed by 12 items such as "I do without thinking'. The SHRI has high internal consistency (α > 0.9), high test-retest reliability (r = 0.91) and high convergent and discriminative validity . In our study, behaviors are: "eating in accordance with the prescribed diet" and "undertaking regular physical activity".
Weight Efficacy Life Style Questionnaire (WELSQ) - Italian version
The WELSQ is composed of 20 items that measure the confidence of the subjects about being able to successfully resist the desire to eat. The questionnaire was used to predict both weight loss and weight loss maintenance across a range of ages in men and women .
Body Uneasiness Test (BUT) - Italian version
The BUT is a self-report inventory that measures body uneasiness by a global severity index and five sub-scales: Weight Phobia, Body Image Concerns, Avoidance, Compulsive Self-Monitoring, Depersonalization .
Binge Eating Scale (BES) - Italian version
The BES is a short self-report questionnaire which measures severity of binge eating . The Italian version of the instrument  consists of 16 items, which are composed by three or four sentences about the severity of binge eating. Cut-off score for mild binge eating symptoms is 17; scores between 18-26 indicate moderate binge eating symptoms and scores over 27 can be associated with a severe binge eating disturbance.
Eating Disorder Inventory (EDI-2) - Italian version
The EDI-2 is a widely used, standardized, self-report measure of psychological symptoms commonly associated with anorexia nervosa, bulimia nervosa and other eating disorders. The EDI-2 does not yield a specific diagnosis of eating disorder. It is aimed at the measurement of psychological traits or symptom clusters presumed to have relevance to understanding and treatment of eating disorders. The EDI-2 consists of 11 subscales derived from 91 items. Three of the subscales were designed to assess attitudes and behaviors concerning eating, weight and shape (Drive for Thinness, Bulimia, Body Dissatisfaction) and the remaining eight ones tapped more general constructs or psychological traits clinically relevant to eating disorders (Ineffectiveness, Perfection, Interpersonal Distrust, Interoceptive Awareness, Maturity Fears, Asceticism, Impulse Regulation and Social Insecurity) [44, 45].
Symptom Check List (SCL-90) - Italian version
The SCL-90 is a brief, multidimensional self-report inventory designed to screen for a broad range of psychological problems and psychopathological symptoms. It consists of 9 symptom scales (Somatization, Obsessive-Compulsive, Interpersonal Sensitivity, Depression, Anxiety, Hostility, Phobic Anxiety, Paranoid Ideation and Psychoticism) and 3 global indices .
Impact of Weight on Quality of Life-Lite (IWQOL-Lite) - Italian version
IWQOL-Lite is the short version of the original IWQOL and is composed by 31 items. The questionnaire is self-report and consists of 5 scales assessing the impact of weight on QoL-related factors such as Physical Functioning, Self-Esteem, Sexual Life, Public Distress and Work. IWQOL-Lite has shown high internal consistency and high test-retest reliability [47, 48]
The Outcome Questionnaire (OQ 45.2) - Italian translation
The OQ 45.2 is an self report questionnaire developed by Michael Lambert in 1996 . The OQ 45 items version is a measure of outcome and it is designed in order to collect repeated measures of patient progress during therapy and after its conclusion. This instrument is one of the most used in psychotherapy research in the U.S. . The OQ 45.2 is composed by 45 items that form 3 scales: Symptom Distress (SD), Interpersonal Relations (IR) e Social Role (SR), and a Global Index.
Descriptive statistics (means ± SD, or median and interquartile ranges, as appropriate) will be used to describe the study sample with regard to baseline characteristics. Before selecting the most appropriate statistical tests, assumptions for parametric analyses will be checked. Repeated-measure ANCOVA will be used in order to evaluate the effects of the intervention when data do not violate the parametric assumptions. The mean differences between intervention and control group with 95% confidence intervals will be calculated. Analyses will be adjusted for possible confounders such as gender and age. Also effect modification will be investigated using interaction terms between intervention group and gender and age, respectively. If data violate parametric assumptions, we will use the exact methods with Monte Carlo approximation, a series of non-parametric statistical algorithms that enable researchers to make reliable inferences when data are sparse, heavily tied or unbalanced, not normally distributed, or fail to meet any of the underlying assumptions necessary for reliable results using the standard asymptotic method . The Mann-Whitney test with Monte Carlo approximation will be used for independent measures, the Wilcoxon rank-sum test for repeated measures and the Fisher exact test for categorical variables. Weight data will be analyzed with an intention-to-treat (ITT) approach with dropouts assumed to have regained 0,3 kg per month, an assumption already used in previous studies [12, 51]. Differently, missing data in the other variables will be replaced with baseline observation carried forward (BOCF) or last observation carried forward (LOCF) as appropriate, assuming no improvement for non-responders patients. Odds ratios with 95% confidence intervals will be also calculated at each follow-up time-point with respect to: 1) the percentage of participants maintaining or improving weight lost at discharge and 2) the percentage gaining a 5% and a 10% of baseline weight reduction for the TECNOB group in comparison with the control group. Finally, logistic regression will be used in order to find out predictors of treatment success defined as weight loss maintenance at the final follow-up time-point.
A confirmatory statistical test with alpha = 0,05 two-sided will be used for the primary outcome (weight loss in Kilograms), whereas explorative statistical tests will be used for all the secondary outcomes. Given the exploratory feature of the latter tests, critical alpha will be maintained at 0,05 two-sided without any correction for multiple comparisons.
All data analyses will be performed using the Statistical Package for the Social Sciences (version 12.0; SPSS, Inc., Chicago, IL).