Impact of ACT-based Interventions on Diabetes-related Outcomes

The VGI is a four-week intervention, adapted from an existing online value-affirmation and goals intervention (Kingston \& Ellett, 2014) and an existing 'Living Well with Physical Health Conditions' programme handbook. Participants are first introduced to the concept of values as understood in Acceptance and Commitment Therapy. They are then asked to complete a card-sort task, which involves organising ten life domains according to their perceived level of importance. Participants will be asked to choose one values that is the most important and meaningful to them and to write for up to 10 minutes about it, thinking about why it is meaningful to them. Following this, participants will be given information on how to set value-based 'SMART' goals and asked to choose one to focus on over the next month. Participants will be sent a reminder e-mail every week over the 4 weeks, asking them to review their progress towards the SMART goal they set themselves.

The MBI is a four-week intervention, where participants are introduced to the concept of mindfulness and acceptance as understood in ACT (Hayes et al., 1999). They will be asked to complete a 10-minute health-focused mindfulness meditation exercise by listening to a recording of a script focusing on cultivating mindful awareness of internal experiences, particularly in relation to diabetes, and practising making room for any difficult internal experiences. This will be followed by some prompts to promote reflections related to their diabetes following the exercise. They will be asked to practise this exercise 3-4 times a week over a four-week period. As a manipulation check, participants will be sent a reminder e-mail every week over the four weeks to record how many times they practised the exercise over the past week.