Preventing weight gain in Higher Education students: a systematic review and a feasibility randomised controlled trial of daily self-weighing or mindfulness in undergraduate nursing students (DOMIN NO)

Background The prevalence of obesity in the UK remains high and continues to rise. Undergraduate nursing students are at significant risk for weight gain. Despite this, few weight gain prevention interventions have targeted this group, and none have been evaluated in the UK. Stress is a well-recognised factor contributing to weight gain, and mindfulness interventions have demonstrated effectiveness in stress reduction. This thesis explores the feasibility and acceptability of two interventions: daily self-weighing and mindfulness training. Aims To assess the feasibility and acceptability of daily self-weighing and mindfulness interventions for preventing weight gain among first-year undergraduate nursing students, using a three-arm randomised controlled trial with embedded process evaluation. Systematic review and meta-analysis A systematic review and meta-analysis were conducted to evaluate interventions aimed at preventing weight gain among higher-education students. Following Cochrane guidance, six electronic databases (Embase, Medline, CENTRAL, CINAHL, PsycINFO, ERIC) were searched, resulting in the identification of 14 randomised controlled trials involving 3,149 participants. The interventions varied widely, and study quality was mixed with considerable heterogeneity. Meta-analyses showed small but statistically significant effects favouring interventions for both weight (−1.20 kg) and BMI (−0.22 kg/m²). All included studies were conducted in North America, highlighting the lack of UK-based evidence and supporting the rationale for the subsequent feasibility trial. Methods This pilot RCT was conducted at a single UK higher education institution, involving first-year undergraduate nursing students at the start of the academic year. Participants were randomly allocated in a 1:1:1 ratio using block randomisation to one of three groups: self-weighing, mindfulness training, or control. The study duration was 14 weeks. The self-weighing intervention involved providing digital scales, offering brief habit formation advice, and encouraging daily weighing with weight diary recording. The mindfulness intervention consisted of four weekly, one-hour online group mindfulness training led by a certified mindfulness instructor, and daily mindfulness practice encouraged through email reminders. The control group received standard healthy eating advice consistent with national guidelines. Quantitative outcome measures included weight, BMI, weighing frequency, perceived stress, mindfulness, and self-regulation of eating behaviour. An embedded qualitative process evaluation was conducted, including semi-structured interviews with participants, analysed using reflexive thematic analysis. Findings A total of 33 first-year nursing students were recruited and successfully randomised in equal numbers (n=11) to the self-weighing, mindfulness, or control groups. Despite successful randomisation, the study faced challenges, including a 21.2% attrition rate at the first follow-up and complete loss to follow-up by the second follow-up point. Adherence to both self-weighing and mindfulness interventions was low. Nine participants completed semi-structured interviews as part of the qualitative process evaluation. Reflexive thematic analysis generated seven key themes, five of which were common across both intervention groups, including “I know it’s important, but I didn’t think it would happen to me,” “Peer observation,” and the interconnected stress-related themes “It’s all down to stress,” “Financial strain,” and “Too busy.” Two unique themes were developed for each intervention arm: “Mindfulness is good, but I need permission” reflected the structural barriers encountered during clinical placements, while “I would forget, and the numbers would upset me” highlighted emotional and behavioural challenges associated with daily self-weighing. Conclusions Preventing weight gain among undergraduate nursing students is an important yet understudied issue. However, this pilot study revealed significant challenges related to recruitment, retention, and adherence, indicating that a full trial is currently unfeasible without major changes. More foundational research is required to better understand weight gain in this population before progressing to intervention evaluation. Future work should focus on developing risk prediction tools, addressing structural and financial barriers, and tailoring interventions to the realities of students undertaking clinical placements with shift work, which present unique challenges, while incorporating stakeholder perspectives and socioeconomic considerations.