THE RELATIONSHIP BETWEEN PHYSICAL ACTIVITY, PHYSICAL FUNCTION AND PSYCHOSOCIAL VARIABLES IN INDIVIDUALS POST-BARIATRIC SURGERY

The incidence of morbid obesity (BMI ≥ 40 kg•mˉ²) is increasing at an exponential rate. Currently, the most viable option for weight loss is bariatric surgery. Success following surgical procedure is guided by the individual's ability to make behavioral changes. A better understanding of the physical activity behavior of individuals who undergo bariatric surgery will enable the development of effective post-surgical exercise guidelines and interventions to enhance surgical weight loss outcomes. PURPOSE: To define the physical activity profile of subjects 2-5 years post bariatric surgery by examining the relationship between physical activity and weight loss. Additionally, this study examines the association between physical function, psychosocial correlates of physical activity, and weight loss. METHODS: Thirty-seven adults (percentage excess weight loss (%EWL) = 62.15 ±19.93, age = 50.76 ±9.99 years) participated. Subjects wore an activity monitor to measure their physical activity. Body height, weight, physical function, psychosocial variables of physical activity (self-efficacy, expected outcomes (benefits) and perceived barriers) and health related quality of life were measured. Assessment also included demographics, medical history, and dietary questionnaires. RESULTS: This study determined that subjects' who have undergone bariatric surgery participated in 205.33 ±136.98 minutes per week of ≥ 3METs for ≥ 1 minute bouts. The average dropped to 47.56 ± 69.84 minutes per week when including only bouts of 10 continuous minutes or more. Physical activity was correlated with %EWL (r=0.47, p=<0.01) and self-efficacy (r=0.39, p<=0.02), but not with physical function, expected outcomes (benefits), perceived barriers, or HRQOL. Physical function was correlated with %EWL (p<0.05). CONCLUSIONS: The subjects' activity level failed to meet standards that have been shown necessary for weight maintenance. Those subjects that were more confident in their ability to exercise were more active and had more success losing weight. These findings suggest that behavioral interventions should include a strategy to address self-efficacy. The disparity between physical activity and physical function would suggest that subjects are capable of performing most exercise and mobility activities. Future research should focus on exercise interventions that address self-efficacy and other behavioral barriers (e.g. musculoskeletal pain, psychosocial factors, and social stigma) with the goal of maximizing post surgical weight loss success

Changes in physical activity behaviour and physical function after bariatric surgery: A systematic review and meta-analysis

Although physical activity performed after bariatric surgery is associated with enhanced weight loss outcomes, there is limited information on patients' physical activity behaviour in this context. This systematic review and meta-analysis assessed pre-operative to post-operative changes in physical activity and physical function outcomes among obese adults undergoing bariatric surgery. A total of 50 studies met inclusion criteria with 26 papers reporting data for meta-analysis. Increases in both objectively recorded and self-reported physical activity at 12months were demonstrated. Studies indicated that there was a shift towards a greater amount of active time, but of a lower intensity within the first 6months of bariatric surgery, suggested by a reduction in moderate to vigorous physical activity but an increase in step count. A standardized mean difference (SMD) of 1.53 (95% CI: 1.02-2.04) based on nine studies indicated improved walking performance at 12months. Similarly, analysis of five studies demonstrated increased musculoskeletal function at 3-6months (SMD: 1.51; 95% CI: 0.60-2.42). No relationship was identified between changes in weight and walking performance post-surgery. More studies assessing physical activity, physical function and weight loss would help understand the role of physical activity in optimizing post-operative weight and functional outcomes