Sociocognitive determinants of lifestyle behaviours of Sri Lankan women with a recent history of gestational diabetes mellitus

Gestational Diabetes Mellitus (GDM) is a common complication of pregnancy that increases the future risk for type 2 diabetes. Lifestyle changes, comprising regular physical activity and healthy eating have been proven to reduce the risk of developing diabetes in high risk groups. This thesis sought to provide a better understanding of the theoretical and contextual factors that influence physical activity and dietary behaviour of Sri Lankan women with a history of GDM. In the first study, semi-structured interviews were conducted to explore women’s experiences in relation to lifestyle changes following a GDM pregnancy. Thirty women who had GDM 6-36 months previously and received obstetric care from the Gampaha Health Service District participated in the interviews. Excessive family demands, low perceived risk, perception of good health, and social norms were identified as barriers to lifestyle change. In the second study, postal and telephone follow-up surveys were conducted from November 2012 to March 2013 to collect information on sociocognitive measures affecting physical activity and diet based on the Health Action Process Approach (HAPA). Study participants were women diagnosed with GDM 6-36 months previously and attended the Colombo North Teaching Hospital for obstetric care. The research hypotheses were tested using structural equation modelling. The hypothesised models explained 11% and 14% of the variance in physical activity and dietary behaviour, respectively. Action self-efficacy was the most important predictor of behavioural intention. Outcome expectancies were important for dietary intention but not for physical activity. Of the post-intentional variables, action and coping planning were important for both physical activity and diet. Though volitional self-efficacy was not a direct predictor of behaviour, women with high self-efficacy were more likely to execute their behaviours through planning. Higher intentions did not directly predict behaviour but the intention-behaviour relationship was mediated by planning. Of the additional variables tested, spousal support was associated with intention formation for both behaviours of interest but was positively associated only with physical activity. This thesis makes a theoretical contribution in this understudied South Asian population in the use of sociocognitive models to develop behavioural interventions. The use of strategies to improve planning and volitional self-efficacy were identified to be helpful to close the intention-behaviour gap. In addition, the importance of spousal support in both the preliminary qualitative work and HAPA modelling may be used to inform future intervention studies among this group