Weight regain after bariatric surgery: the role of surgical procedure and dietitian follow-up

Abstract

Introduction: Bariatric surgery (BS) is an effective long-term treatment for severe obesity, resulting in substantial weight loss (WL). However, weight regain (WR) is a common physiological response influenced by metabolic adaptation, plus physiological and behavioural factors, and may differ between surgery types. Postoperative dietitian follow-ups are vital for maintaining adherence and minimising WR.
Aim: To compare WR between two BS procedures (sleeve gastrectomy [SG] and Roux-en-Y gastric bypass [RYGBP]) and to evaluate the association between postoperative dietitian follow-up adherence and WR.
Methods: An observational ambispective (retrospective–prospective) analytical cohort study with a 10-year follow-up was conducted in Gauteng, South Africa, from March 2020 to January 2021. Adults (≥ 18 years) who underwent BS (SG or RYGBP) between 2009 and 2018 were included. Data on sociodemographics, anthropometry, and dietitian follow-up attendance were collected from multidisciplinary team retrospective medical records and cross-sectionally through structured telephone interviews (EvaSysTM).
Results: Amongst 100 participants, 70.0% underwent RYGBP. The median age was 48.0 years (yrs) (IQR: 43.0–55.5), with more females (79%, p = 0.047). Median preoperative body mass index (BMI) was 44.8 kg/m² (IQR: 41.5–50.9), and median follow-up duration was 6.9 yrs (IQR: 5.0–8.4); longer in SG (9.0 yrs vs. 6.3 yrs, p = 0.0001). Overall, 63.0% were classified as good responders (≥ 50 percentage excess weight loss [%EWL]), with a higher proportion in RYGBP than in SG (72.9% vs. 40%, p = 0.002). Overall, median %EWL was 59.9%, lower in SG than RYGBP (44.2% vs. 61.6%, p = 0.008). Excess WR (> 15%) occurred in 67.0% of participants by two years post-surgery. Median WR of 23.3% (IQR: 12.6–37.5), beginning at a median of 2.3 yrs (IQR: 1.5–
4.0), with SG showing higher median %WR than RYGBP (32.3% vs. 21.7%, p = 0.032). From the second postoperative year onwards, attendance at dietitian follow-up visits was poor (< 50%).
Conclusion: Approximately two-thirds achieved successful weight loss (≥ 50% EWL), with better outcomes observed following RYGBP compared with SG. However, excessive WR was common, occurring in 67% and beginning at about 2.3 yrs post-surgery. Poor attendance at dietitian follow-up visits was observed. 

Keywords: excess weight loss (EWL), obesity, Roux-en-Y gastric bypass (RYGBP), sleeve gastrectomy (SG)