Factors associated with different patterns of weight change after bariatric surgery: A longitudinal study

Abstract

BackgroundThe mean weight loss (WL) after successful bariatric surgery is approximately one third of the initial body weight, which is mainly achieved between the first 2 years of follow‐up. However, 15%–35% of patients do not achieve a significant percentage of total WL (%TWL). Information on factors associated with a higher or lower WL after bariatric surgery is limited. This study aimed to assess the change in %TWL and describe the factors associated with greater or lesser WL over time.MethodsThis prospective longitudinal study included patients treated with laparoscopic Roux‐en‐Y gastric bypass or sleeve gastrectomy. Baseline data were recorded before surgery. Follow‐up was performed at 3 (n = 141), 6 (n = 208), 9 (n = 115), 12 (n = 216), 24 (n = 166), and 36 months (n = 99). Generalized estimating equation analysis was performed to assess the changes in %TWL over time and factors associated with different patterns of WL.ResultsIn total, 231 patients were included (women, 82.2%; basal body mass index (BMI) 41.4 ± 5.1 kg/m2). The tendencies to increase %TWL (32 ± 6.5) were evident in the first year and stabilized thereafter. Sustained nutritionist follow‐up (2.3%, p = 0.004), baseline BMI >40 kg/m2 (0.4%, p < 0.001), and WL ≥ 10 kg before surgery (0.3%, p = 0.001) were associated with a higher %TWL. Patients who performed physical activity >30 min/day after surgery reduced their %TWL by 0.6% (p = 0.002).ConclusionsModifiable factors such as nutritional monitoring and WL before surgery are associated with a significant increase in %TWL over time. Basal BMI was associated with a significant decrease in %TWL.