Literature on the predictors of health behaviour initiation, interruption, consistency and discontinuation is scarce. This study sought to fill this gap by suggesting a model that takes into account these variables. Using the structural equation modelling, we surveyed 470 social media users in Nigeria and found that perceived vulnerability, perceived seriousness; benefits to action, self-efficacy and cues to action significantly predict health behaviour initiation. Also, the predictors of health interruption were found to be perceived vulnerability, perceived seriousness, benefits to action, challenges to action and perceived realness. The predictors of health behaviour consistency were found to be perceived vulnerability, perceived seriousness, benefits to action, perceived realness, self-efficacy and cues to action. Finally, the predictors of health behaviour discontinuation were found to be perceived vulnerability, perceived seriousness, perception on realness, behaviour fatigue and behaviour discomfort. We explored the implication of these results on health promotion and made suggestions for further studies.