Quality of Life, BMI, and Physical Activity in Bariatric Surgery Patients: a Structural Equation Model.

Abstract

The purpose of this study was to use a structural equation model to clarify how physical activity (PA), sex, and BMI relate to quality of life (QoL) of post-bariatric surgery patients. The study had a retrospective cohort design for a convenience sample population of 886 bariatric subjects (38 ± 8.49years). QoL was assessed using World Health Organization Quality of Life-BREF, PA using the International Physical Activity Questionnaire, and BMI values were calculated. Structural equation analysis was conducted in Mplus. The physical domain presented positive relationships with BMI (p = 0.014) and the very active group and negative with the insufficiently active A and B groups and sex (p < 0.001). The psychological domain presented negative associations with BMI and the very active group and positive with the insufficiently active A group. The social relations domain presented negative associations with BMI (p < 0.009) and the very active group (p < 0.002) and positive with the insufficiently active A (p < 0.007) and B (p < 0.019) groups. The environmental domain was negatively associated with BMI (p < 0.004) and the very active group (p < 0.001) and positively with the insufficiently active B group (p < 0.049) and sex (p < 0.018). BMI is a negative predictor of QoL in bariatric patients and this trend was not observed in the physical domain only; also, the very active group was negatively associated with QoL. We believe that distortions in body weight/body size extend to PA, and research is needed to explore the psychological factors underlying the overestimation of the amount of PA performed.