PhD (Nursing) candidate
Eating behaviours of Australian bariatric surgery patients
Supervisors: Donna Waters and Judy Lumby
Obesity as a disease and as a risk factor for other major diseases has become a worldwide epidemic and an international health priority (World Health Organisation, 2000). Conventional treatments such as diet, exercise, behavioural and pharmacological therapies are unsustainable (Levin, 2005) with more than ninety per cent of patients regaining weight within one to two years (Levin, 2010). Surgery to treat obesity (bariatric surgery) is recommended as the appropriate intervention when other methods have failed (NHMRC, 2003) and for the treatment of type two diabetes when associated with obesity (International Diabetes Federation, 2011). A federal government inquiry into obesity has recommended bariatric surgery as a last resort (Australian Parliament House of Representatives Standing Committee on Health and Ageing & Georganas, 2009). Last year there were approximately 13,000 bariatric procedures performed in Australia.
Although bariatric surgery results in long term sustainable weight loss, the resolution of co morbid conditions (in particular type two diabetes), a survival advantage, and improved quality of life measures, recent evidence suggests that weight loss failure occurs in an estimated 20% to 30% of patients (Ahroni, Montgomery, & Watkins, 2005; Angrisani, Lorenzo, & Borrelli, 2007) and diabetes improves but does not resolve in 15% of patients (Scott & Batterham, in press). Varying adverse outcomes are reported for each procedure. Intense research interests include mechanisms that induce weight loss by overriding homeostatic regulation of energy via neural hormonal complex pathways affecting hunger and satiety levels (Scott & Batterham, in press).
The purpose of this longitudinal study is to observe hunger and satiety as demonstrated by eating behaviours associated with three bariatric surgery procedures in Australian patients: Adjustable gastric banding (AGB); Gastric bypass (GBP); and Sleeve gastrectomy (SG) in the intermediate and long term follow up periods.
Three procedures are currently performed in the Australian context for the treatment of severe obesity or obesity where one or more co morbid conditions exist. Whilst AGB and GBP procedures dominate internationally there is recent increasing demand for the SG procedure. Indications for best procedure for individual patients are unknown. This study will potentially provide evidence of differences in the eating behaviours associated with each procedure, how eating behaviours may change over time, and whether any eating behaviours in particular correlate with more or less weight loss. Thus it will provide some evidence to assist patients to discern and inform their choice of procedure balancing risks with benefits, and assist bariatric health professionals to provide pertinent evidence based information to patients. Further, the findings would inform multidisciplinary teams such as bariatric registered nurses, dietitians, psychologists and exercise physiologists in developing educative programs and supportive strategies based on eating behaviours conducive to weight loss post surgery. Finally, the study has implications for Australian and international bariatric patients with this chronic and complex disease of obesity to perhaps expect changes in hunger and satiety over time and possibly within different procedure types.