The effectiveness and cost effectiveness of Snacktivity™ as an intervention to promote physical activity and health outcomes: a study protocol for a multi-centre randomised controlled trial

Abstract

Background: A novel ‘whole day’ approach that could motivate the public to be more physically active is termed Snacktivity™. Consistent with guidance, the Snacktivity™ approach encourages the public to accumulate ≥ 150 min of physical activity in short 2–5-min ‘activity snacks’ of moderate-vigorous intensity physical activity throughout the day/week. Snacktivity™ also promotes muscle-strengthening activity twice per week. Following completion of research to co-design and develop the Snacktivity™ approach, the aim of this trial is to assess the effectiveness and cost-effectiveness of a Snacktivity™ intervention to increase physical activity and reduce future risk of disease in the population, compared with usual care. Methods: A multi-centre, two-arm, individually randomised, parallel group, superiority trial, with an economic evaluation, will be conducted in 966 physically inactive adults. Participants will be recruited from National Health Service Trusts and organisations and non-National Health Service settings (e.g. community groups and social media). Participants will be individually randomized (1:1) to the Snacktivity™ intervention group or a usual care comparator group. The Snacktivity intervention involves two main components; a brief 5-min consultation about the principles and purpose of Snacktivity™; and access to technology support (mobile phone app called the SnackApp, linked to a Fitbit activity device (Versa 4)) that through behavioural change techniques promote self-monitoring of physical activity, habit formation, action planning and feedback on the number of activity snacks completed each day. The primary outcome is the difference in average minutes of moderate-vigorous physical activity between the groups at 12-months follow up, measured using a wrist worn accelerometer. Secondary outcomes include accelerometer-assessed average minutes per day of light, moderate, and vigorous intensity physical activity, time sedentary, weight and psychological health outcomes, at 12 month follow-up. Discussion: Innovative interventions such as Snacktivity™, that aim to support the public to increase their physical activity each day are required. Findings could inform future public health guidance and public health messaging that seeks to raise awareness in the population of the potential benefits of Snacktivity™ for health. Trial registration: ISRCTN: 12390945. Registered on 22 March, 2024.