Exposure to food stimuli often elicit aversive emotions in patients with anorexia nervosa, which can perpetuate eating-related avoidance. Exposure therapy has been shown to effectively reduce anxiety toward, and avoidance of, feared stimuli in several psychiatric disorders. Digital technologies, such as virtual reality (VR) have been employed to implement exposure therapy in situations where in vivo exposure is unfeasible, challenging, or perceived as threatening by patients. VR has also the potential to be used by individuals repeatedly in their own time and environment, to consolidate new learning. This pilot randomised controlled study evaluates the feasibility and clinical impact of repeated VR exposure to food stimuli in patients with anorexia nervosa attending intensive daycare treatment (treatment as usual, TAU). VR food exposure will be compared to the use of a relaxation-focused VR scenario (natural environment) and a control condition (no use of VR). Patients in all groups will receive TAU.

Patients with anorexia nervosa are recruited from daycare services at Eating Disorder Units in Italy. Inclusion criteria are: (1) current diagnosis of anorexia nervosa according to DSM-5 criteria; (2) 14 years or older. Exclusion criteria are: (1) diagnosis of neurological disorders, (2) diagnosis of psychosis or substance abuse disorders, (3) visual/hearing impairments not corrected by glasses/ear implants; (4) non-tolerance of exposure to VR (i.e., cybersickness, dizziness).

Each patient is randomly assigned to one of three conditions: repeated food exposure in a VR kitchen environment + TAU, repeated exposure to a VR natural setting + TAU, or TAU alone .

VR Food Exposure: Patients in this condition undergo one session of VR exposure in a kitchen environment each day for 5 consecutive days (from Monday, day 1, to Friday, day 5). Each session lasts 5 minutes. The VR environment has been specifically developed by the study team and it was tested in a previous one-session study. The scenario consists of a kitchen with foods of different calorie contents either immediately visible in the environment (for example on a table) or stored in drawings, refrigerators, cabinets. Once in the kitchen, patients can freely move, open the cupboards and the fridge, and grab and hold the foods. Patients are invited to explore the environment and interact with the stimuli they feel most comfortable with. Based on their preference, in each session participants access one of three versions of the virtual kitchen: the virtual kitchen alone, a virtual kitchen + a pink elephant (designed to induce positive mood), or a virtual kitchen + a reassuring voice that encourages to interact with foods and face food-related fears.

VR Nature Exposure: Patients in this condition undergo one session of VR exposure to a natural scenario each day, for 5 consecutive days (from Monday to Friday), through the NatureTreks app. Each session lasts 5 minutes. Participants perform the exposure while seated, and are instructed to observe the environment and try to relax. Based on their preference, in each session participants are able to choose one of three different natural environments: a white sand beach ("Blue Ocean"), a snowy mountain ("White Winter"), or a forest in autumn foliage ("Red Fall")

TAU: It consists of a daycare program (attendance Monday to Friday) including individual psychological therapy (based on cognitive-behavioral principles), nutritional counseling, assisted meals, group activities (e.g., psychotherapy, art therapy, music therapy, relaxation protocols), and psychoeducation for family members. For ethical reasons, at the end of the follow-up assessment, participants in the control group are given the opportunity to engage in VR exposure.

Patients in all conditions complete a baseline (day 0) and end of intervention (day 5) assessment. The baseline assessment includes:

• Demographic questionnaire (age, years of education, current pharmacological treatments, height, weight)
• Eating Disorder Examination Questionnaire
• Depression, Anxiety and Stress Scale
• Difficulties in Emotion Regulation Scale
• Positive and Negative Affect Schedule
• State and Trait Anxiety Scale
• Motivational Ruler: patients are asked to rate, on a scale from 0 to 10 importance and ability to change.
• Food evaluation: patients are asked to rate, on a scale from 0 to 100 wanting, liking and fear of 21 foods of different caloric content.
• Meal related anxiety: just before starting their meal at the hospital, patients are asked to rate their current level of anxiety on a scale from 0 to 10.

The PANAS, the STAI, the motivational ruler, food evaluation, and meal related anxiety are completed at the end of intervention.

Each day, immediately before and after the exposure, participants in the food and nature exposure groups are asked to rate, on a scale from 0 to 100, their anxiety in the moment and also the anxiety they feel when thinking of the next meal. At the end of each exposure session, they are asked to rate their sense of presence and discomfort in the VR environment.

Inclusion Criteria:

• current diagnosis of anorexia nervosa according to DSM-5 criteria
• 14 years or older.

Exclusion Criteria:

• diagnosis of neurological disorders
• diagnosis of psychosis or substance abuse disorders
• visual/hearing impairments not corrected by glasses/ear implants
• non-tolerance of exposure to VR (i.e., cybersickness, dizziness)

a plan will be established by the research team for data sharing following publication of the first manuscript