AbstractsWomens Studies

Research Doctorate - Doctor of Philosophy (PhD) The rising prevalence of overweight and obesity, the health and financial consequences associated with weight gain, and the modest and often unsustainable weight loss from obesity treatment interventions mean that it is now considered more effective to prevent obesity in healthy weight and overweight populations. Mid-age women (45-54 years) are at high risk of weight gain and studies indicate women will likely continue to gain weight and increase their waist circumference post menopause unless effective weight gain prevention initiatives are implemented. Despite this, there is limited evidence for weight control interventions in women about to undergo the menopause transition, with only one published study. The primary purpose of this thesis was to determine the effectiveness of a 12-month health professional Motivational Interviewing (MI) intervention aiming to improve dietary intake and physical activity behaviours for weight gain prevention in non-obese, mid-age women. This thesis explored the use of MI, a client-centred, guiding counselling style, for dietary and physical activity behaviour change. Three research studies were undertaken to meet these aims. The first study was a systematic review of evidence for diet and physical activity behaviour change in response to MI interventions in comparison to an attention control. Two of the five articles reporting on dietary behaviour change found a significant positive effect on fat and percent energy from fat favouring MI. None of the six articles reporting on physical activity found any difference between MI and an attention control. Due to the limited number of studies and the poor methodological quality of the included studies, there is not yet sufficient evidence to conclude that MI enhances diet and physical activity behaviour change above an attention control, although the results from two studies suggest a positive effect. More high quality studies that objectively measure diet and physical activity, evaluate and report MI fidelity and compare the MI intervention to an attention control are required. The second and major study was the ‘40 Something’ parallel-group Randomised Controlled Trial (RCT) which tested the effectiveness of a 12 month MI health professional intervention (MI; n=28) for weight gain prevention in non-obese, mid-age women in comparison to a self-directed intervention (SDI; n=26) that received tailored written materials. The study followed participants for an additional 12 months to assess effect maintenance. At 12 months, the MI group weighed 65.6 kg (95% CI 64.5, 66.8) which was significantly different (p=0.034) from the SDI group who weighed 67.4 kg (95% CI 66.2, 68.6). When stratified by baseline BMI category, the MI group lost significantly more weight (-2.6kg, 95% CI -3.9, -1.2) than the SDI group (-0.1 kg 95% CI -1.2, 1.0 p=0.002) for the healthy weight women. The overweight women lost weight regardless of whether they were allocated to the MI (-3.5kg, 95% CI -6.1, -1.0) or SDI group…