An investigation in adults to determine if physiological responses to visual food cues are associated with addictive eating behaviour

This pilot study has a within subject study design. After determining eligibility, via an online screening, participants will complete a series of standardised questionnaires (Yale Food Addiction Scale, Addiction-like Eating Behaviour Scale, The Self-Report Habit Index, The Power of Food Scale, Perceived Stress Scale, Generalized Anxiety Disorder scale, The Patient Health Questionnaire, The Substance Use Risk Profile Scale) online prior to attending a one-off experimental session at the University of Newcastle. On arrival participants will have their height and weight measured by a trained assessor. Participants will complete an IT-mediated task, integrated with physiological measures (heart rate variability, electrodermal activity and pupillary responses) under controlled conditions. This task will involve viewing two x 5min food image paradigms (healthy vs. hyperpalatable foods) on a computer monitor with a 2min wash-out period of neutral images (non-food images) shown in between. Participants will be randomly allocated by block design to group 1 or group 2. Group 1 will view healthy food images first, and hyperpalatable food images second. Group 2 will view hyperpalatable food images first, and healthy food images second. Participants will complete a self-report measure of current hunger (Visual Analogue Scale) before and after viewing the images, and emotional response to images will also be recorded via paper based survey at the end of the session. The session will take approximately 45min to complete and will be administered by an Accredited Practising Dietitian. Image paradigms: food image stimuli to be used in this task has previously been rated in a pilot study (n=10 adults, independent of those involved in the present study) to ensure foods are representative of each of the two categories, and food images are readily identifiable i.e. recognisable and familiar, and shown in an appetising manner for Australian adults. Images are from a licensed database and non-copyrighted sources. Healthy food pictures are based on the five core food groups, and hyperpalatable food pictures based on foods categorised as discretionary choices, outlined in The Australian Guide to Healthy Eating. Intervention adherence: Visual Analogue Scale (VAS) will provide pre and post summary scores to aid in determining if the image paradigms were effective in eliciting appetite and hunger responses. An on/off task will be conducted during the image paradigms to identify non-responders i.e. images will be auto advanced with the exception of 2 timepoints. At 100s and 200s participants will be asked to manually ‘click next’ on the computer screen to enable viewing of the next image. To maintain fidelity each experimental session will be conducted in the same laboratory room and one researcher (Accredited Practising Dietitian) will conduct all the sessions, including anthropometric measurements.