8287801 SHAPE: Shift workers’ health awareness & prevention and reduction of excess weight’ rationale and design – a combined lifestyle intervention

<h3>Objective</h3> Night-shift work leads to disruption of an individual’s usual sleep-wake and light-darkness patterns leading to problems with maintaining healthy lifestyle behaviors and to circadian misalignment. Consequently, night-shift work is associated with increased BMI and a higher risk of (abdominal) obesity. Previous behavioral interventions in night-shift workers have shown modest improvements in health, but no combined lifestyle intervention (CLI) has yet been implemented for shift workers. Therefore, the SHAPE-study proposes an evidence-based CLI to promote behavior changes in four lifestyle domains (sleep, diet, physical activity, and stress management) amongst night-shift workers, in order to reduce and prevent obesity, and improve metabolic health. <h3>Methods/Results</h3> In this intervention study (pre-post design), 400 night-shift workers in Europe will undergo a 24-week CLI, following a run-in period. The CLI targets improvements in the four lifestyle domains mentioned above, and is grounded in the Integrated Behavior Change (IBC) model, which incorporates both volitional and automatic processes to support sustained behavior change. Participants will be randomly allocated into two groups, each having a different sequence of the lifestyle domains to control for possible ordering effects, where they receive lifestyle advice and behavioral change techniques throughout a mobile app and hybrid workshops to promote peer support. Measurements will be done at baseline and follow-up after 3, 6 and 12 months. The main expected outcomes are behavioral changes in sleep quantity, diet quality, physical activity, and perceived stress, which will analyzed with mixed models. <h3>Discussion/Conclusion</h3> Night-shift work is prevalent and difficult to limit in our 24/7 society, yet there is currently limited evidence on effective combined lifestyle interventions to prevent negative health consequences in a real-life context. The SHAPE-study will contribute to this need by evaluating the effects of a promising evidence-based CLI aimed at behavior change to improve metabolic health amongst night-shift workers.