Contributions of psychology to understanding the processes at the base of stability and changes in eating disorders and obesity with a multidisciplinary approach in public health contexts

Feeding and Eating Disorders (FEDs), as well as altered states of nutrition, are complex and multifactorial conditions that represent public health challenges with severely adverse outcomes on physical and mental health and high costs for society. Research and scientific health institutes are aligning with the employment of multidisciplinary, integrated approaches that can provide help to individuals at multiple levels while addressing the sustainability of such interventions. After a brief theoretical description of FEDs, obesity and their psychological correlates, including a discussion of risk and maintaining factors, theoretical models, and evidence-based interventions, this thesis will present four studies developed within the project “Determinants of quality of life in patients with altered nutritional status before and after integrated multidisciplinary nutritional rehabilitation treatment”, approved from the Ethical Committee of Policlinico Umberto I, University of Rome La Sapienza (Ref. 5915), presented in chapter two. The studies are divided into two parts: Part 1 focuses on multidisciplinary assessment and understanding of FEDs and obesity, and includes research on the association between emotional neglect and Binge Eating Disorder (BED) and the mediating role of Weight Stigma between pressures from health professionals to lose weight and binge eating episodes; Part 2 addresses multidisciplinary intervention for FEDs specifically with the support of technology, including a meta-analysis on the web-based interventions for established or subthreshold FEDs, and an original online group intervention for Bulimia Nervosa (BN) and BED, based on Dialectical Behaviour Therapy (DBT). At the end of both Part 1 and Part 2, two future projects for screening and intervention of disordered eating conditions are presented. Overall, these findings underscore the need for a sustained commitment to multidisciplinary, patient-centred approaches that take into account the social, biological, and psychological factors shaping feeding and eating disorders and obesity, while emphasising the central contribution of psychology to the development of effective, scalable, and sustainable public health strategies.