N-of-1 Study of Weight Loss Maintenance in People who Lost Over 5% of Body Weight.
1Newcastle University, Institute of Health and Society, UK
2Fuse, UKCRC Centre for Translational Research in Public Health, UK
3University of Stirling, UK
Background: This study aimed to advance understanding of explanatory variables associated with weight loss maintenance (WLM). Methods: We used a series of n-of-1 studies and McKnight bootstrapping approach to explore WLM in 12 people who in the previous year lost over 5% of their body weight. For two months we used ecologic momentary assessment to gather daily data on motivation, self-regulation, resources, habits and environmental and social influences (predictive variables) and weight, physical activity and ability to follow a WLM plan (outcome variables). Results: For all 12 participants, daily fluctuations of each of the 3 outcomes were significantly predicted by explanatory variables. Patterns of variables contributing to the prediction, amount of variability accounted for and autoregression differed between participants. Discussion: Divergent maintenance-related variables showed differential impact on ability to maintain weight, engage in physical activity and to follow a WLM plan for different individuals. The n-of-1 design offers useful tool for developing and testing theory of behaviour change maintenance.