RESUMEN
A vegan diet, which excludes all animal-derived products, has been associated with some improvements in health, while also conferring environmental benefits. Understanding the psychological determinants of successfully switching to a vegan diet will help to inform the design of interventions supporting long-term dietary change. Studies to date have tended to focus on reasoned motives underlying the decision to initiate such a dietary shift. Yet, focusing on reasons for switching may overlook the importance of a broader range of psychological factors that may help or hinder attempts to maintain a vegan diet. This qualitative interview study, the timing of which coincided with UK Covid-19 lockdowns, documented experiences of 20 young adults (17 female; mean age 22y) who attempted to adopt a vegan diet in the past nine months and had or had not successfully maintained this change. Reflexive Thematic Analysis identified five themes surrounding initiation and maintenance. A theme of 'motives, expectations and cues to switching' showed that switching was motivated by ethical or health concerns, and cued by Veganuary, lockdown or health issues. 'The effortfulness of switching' captured experiences of the perceived burden imposed by adhering to the diet due to, for example, a perceived lack of accessible vegan options. The 'flexibility of dietary rules' theme showed that many found the 'no animal products' rule clear but restrictive, so allowed themselves occasional non-meat animal products. 'Social acceptability concerns' captured the importance of acceptance from vegan and non-vegan family and friends, and 'satisfaction with the switch' described the perceived benefits that sustained maintenance for many. Our findings suggest that interventions should seek to support people to overcome potentially unforeseen practical and social challenges to adhering to a vegan diet.