The OB-WELL Project: Study Protocol for a Three-Arm Randomized Controlled Trial of an Internet-Based Self-Help System for Psychological Support in Obesity

INTRODUCTION Clinical obesity is defined as a chronic, multifactorial disease characterized by excessive adipose tissue accumulation associated with measurable dysfunction in organ and tissue systems and/or clinically meaningful, age-adjusted impairments in daily functioning. Obesity exerts systemic effects across multiple physiological domains and significantly increases the risk of severe comorbidities, including type 2 diabetes, cardiovascular and cerebrovascular diseases, hypertension, dyslipidemia, several malignancies, osteoarthritis, reproductive disorders, and premature mortality.

Beyond its clinical burden, obesity represents a rapidly escalating global public health challenge. Epidemiological projections indicate a substantial increase in prevalence over the past decades, with profound implications for healthcare sustainability and resource allocation worldwide.

In parallel, robust evidence demonstrates that obesity is associated with elevated levels of psychological distress, including higher rates of depression and anxiety relative to normal-weight populations. Psychological factors-such as affective symptoms, maladaptive eating behaviors, perceived stigma, discrimination, and chronic stress-contribute not only to onset but also to the persistence and progression of obesity. Accordingly, contemporary clinical guidelines increasingly recommend the integration of structured psychological interventions within multidisciplinary obesity care pathways.

Cognitive-Behavioral Therapy (CBT) has demonstrated efficacy in improving both weight-related and psychological outcomes through techniques such as cognitive restructuring, behavioral activation, goal setting, action planning, and relaxation training. However, although short-term benefits are well established, evidence suggests that partial weight regain and attenuation of psychological gains may occur following treatment discontinuation, highlighting challenges related to long-term adherence and maintenance. Structural barriers-including high treatment costs, geographic inaccessibility, and limited continuity of care-further constrain the scalability of traditional face-to-face interventions.

These limitations underscore the need for technology-enabled, scalable, and sustainable intervention models. Digital and telemedicine-based psychological interventions have emerged as promising solutions to enhance accessibility, optimize cost-effectiveness, and support longitudinal behavioral regulation in individuals with obesity.