Follow-up Strategies in Metabolic and Bariatric Surgery: Current strategies and Challenges

Abstract

Metabolic and bariatric surgery (MBS) is an effective treatment for severe obesity and its related comorbidities. However, the long-term success and safety of these procedures depend heavily on continuous postoperative follow-up. Postoperative follow-up during the first year is essential for detecting surgical complications, monitoring weight loss trajectories, and optimizing nutritional status. Long-term follow-up is equally important for preventing weight regain, micronutrient deficiencies and recurrence of metabolic diseases. Structured and lifelong follow-up is a fundamental component of successful MBS. Despite recommendations from international societies, adherence to structured follow-up remains inconsistent in real-world practice. This review summarizes current evidence on optimal follow-up strategies after MBS, focusing on nutritional monitoring, management of complications, metabolic surveillance, psychosocial support, and multidisciplinary care.

INTRODUCTION

Metabolic and bariatric surgery (MBS) is currently the most effective treatment for severe obesity and obesity-related metabolic diseases, providing sustained weight loss and significant improvement in comorbidities such as type 2 diabetes mellitus, hypertension, dyslipidemia, and obstructive sleep apnea [1,2,3,4]. As surgical techniques and perioperative safety have advanced, the focus of bariatric care has increasingly shifted toward long-term outcomes and postoperative management [5,6,7].

Unlike many surgical procedures, MBS dose not represent a one-time solution but rather a lifelong metabolic intervention. The long-term success of MBS depends largely on structured postoperative follow-up, which plays a critical role in monitoring weight trajectory, detecting complications, preventing nutritional deficiencies, and supporting behavioral and lifestyle modification [3,8]. Nevertheless, real-world adherence to structured follow-up remains suboptimal, particularly beyond the first postoperative year [8,9].

Numerous studies have demonstrated that insufficient follow-up is associated with weight regain, late complications, nutritional deficiencies, and deterioration of metabolic outcomes [9,10,11]. Despite the availability of international guidelines emphasizing lifelong follow-up, implementation in daily clinical practice remains inconsistent, and follow-up strategies vary significantly across institutions and healthcare systems [12,13].

This review discusses challenges in conventional follow-up after MBS and summarizes current evidence on optimal follow-up strategies after MBS.

CHALLENGES IN POSTOPERATIVE FOLLOW-UP AFTER MBS

The first postoperative year is crucial for successful postoperative care. Previous studies have demonstrated a progressive decline in follow-up adherence over time. While early postoperative attendance within the first 6–12 months is relatively high, follow-up rates decrease substantially thereafter, with reported attrition rates exceeding 40–60% at 2–5 years postoperatively [14,15,16]. Several studies have shown that patients who maintain long-term follow-up after MBS experience better postoperative outcomes [17,18]. Conversely, loss to follow-up has been associated with an increased risk of adverse events, including nutritional deficiencies and weight regain [19,20,21,22]. Accordingly, previous studies and clinical guidelines recommend lifelong surveillance for patients undergoing MBS [3,23,24,25]. Despite this broad consensus, maintaining long-term follow-up in clinical practice remains challenging. Patient-related factors such as younger age, male sex, long travel distance to tertiary centers, and lower socioeconomic status have been associated with poor follow-up adherence [26,27,28,29,30]. Therefore, identifying these risk factors and developing strategies to improve follow-up adherence are critical for ensuring effective long-term postoperative care.

In addition, structural and systemic barriers may further limit the effectiveness of conventional follow-up models. In many institutions, postoperative follow-up is primarily surgeon-centered and focused on short-term surgical outcomes such as weight loss, wound healing, and procedure-related complications, which may be insufficient to address the complex metabolic, nutritional, and behavioral consequences of MBS [21,31,32].

From the patient’s perspective, financial costs, time constraints, transportation difficulties, and the misconception that follow-up is unnecessary once weight loss stabilizes may also contribute to poor adherence. Furthermore, because many nutritional deficiencies develop gradually and remain asymptomatic for extended periods, patients may underestimate the importance of continued surveillance [33,34,35].

Healthcare system factors, including limited insurance coverage for long-term monitoring, lack of standardized national follow-up pathways, and insufficient integration between surgical and medical services, may further contribute to fragmented postoperative care [36,37]. Collectively, these findings highlight the need to identify patients at high risk of follow-up loss and to develop systematic and sustainable strategies to improve long-term follow-up after MBS.

POSTOPERATIVE NUTRITIONAL DEFICIENCIES AND THE IMPORTANCE OF LIFELONG FOLLOW-UP

Nutritional deficiencies are among the most frequent long-term complications after MBS and represent a major rationale for structured postoperative surveillance. These deficiencies arise from reduced dietary intake, altered gastrointestinal anatomy, and impaired nutrient digestion and absorption, with the specific mechanisms varying according to the surgical procedure [31,32,33]. Restrictive procedures such as sleeve gastrectomy mainly reduce gastric capacity and nutrient intake, whereas bypass procedures including Roux-en-Y gastric bypass and one-anastomosis gastric bypass additionally impair nutrient absorption by excluding the duodenum and proximal jejunum. Consequently, a wide range of micronutrient deficiencies has been reported, most commonly involving iron, vitamin B12, folate, vitamin D, and calcium, while protein malnutrition and deficiencies of thiamine, zinc, and fat-soluble vitamins may also occur [38,39,40]. Importantly, many of these deficiencies develop gradually and remain clinically silent for prolonged periods. If left unrecognized, however, they may lead to serious complications such as anemia, peripheral neuropathy, cognitive impairment, osteoporosis, and sarcopenia [41,42,43,44]. Because these deficiencies can emerge months or even years after surgery, regular laboratory monitoring and long-term clinical surveillance are essential. Several studies have shown that patients who fail to maintain regular follow-up are at increased risk of micronutrient deficiencies and other adverse outcomes [45,46]. Accordingly, current clinical guidelines consistently recommend lifelong follow-up after MBS, including periodic clinical assessment, nutritional counseling, and routine laboratory surveillance (Table 1) [3,47,48].

Table 1. Recommended laboratory monitoring after MBS.

Laboratory test	Suggested frequency	Clinical purpose
Complete blood count	Every 6–12 months	Detection of anemia
Iron studies (ferritin, transferrin saturation)	Every 6–12 months	Detection of iron deficiency
Vitamin B12	Annually	Prevention of neuropathy and anemia
Folate	Annually	Detection of megaloblastic anemia
Calcium	Annually	Bone metabolism monitoring
Vitamin D (25-OH vitamin D)	Annually	Prevention of osteoporosis
Albumin/total protein	Annually	Detection of protein malnutrition
Thiamine (vitamin B1)	When clinically indicated	Prevention of neurologic complications
Zinc and copper	When clinically indicated	Detection of trace element deficiencies
Parathyroid hormone	Annually	Assessment of secondary hyperparathyroidism

MBS = metabolic and bariatric surgery.

CURRENT INTERNATIONAL GUIDELINES ON POSTOPERATIVE FOLLOW-UP

Several clinical guidelines have addressed postoperative follow-up after MBS. Although specific recommendations vary slightly among guidelines, there is broad consensus that structured and lifelong follow-up is essential to optimize long-term outcomes (Fig. 1) [3,47,48]. Close monitoring during the first postoperative year is generally recommended to evaluate weight loss, detect early surgical or metabolic complications, and assess nutritional status. Beyond the first year, most guidelines recommend at least annual follow-up visits including clinical assessment, nutritional counseling, and laboratory surveillance for micronutrient deficiencies [12,48]. Lifelong vitamin and mineral supplementation are also universally recommended, with supplementation regimens tailored according to the type of procedure. In addition, multidisciplinary care involving surgeons, physicians, dietitians, and mental health professionals is emphasized to support long-term weight maintenance and metabolic health. While these guidelines provide a structured framework for postoperative management, their implementation varies across healthcare system [25]. In Korea, standardized national recommendations specifically addressing long-term postoperative follow-up remain limited, and follow-up practices are largely institution-dependent [49,50]. A summary of key recommendations from major guidelines is presented in Table 2.

Fig. 1. Proposed framework for long-term follow-up after metabolic and bariatric surgery.

Postoperative follow-up after metabolic and bariatric surgery should include structured monitoring across different phases. Early follow-up focuses on detection of surgical complications and nutritional assessment, whereas intermediate and long-term follow-up emphasize weight maintenance, surveillance for micronutrient deficiencies, and management of metabolic comorbidities. Lifelong multidisciplinary care is essential to optimize long-term outcomes.

Table 2. Comparison of guidelines for postoperative follow-up after MBS.

Guideline	Follow-up Duration	Visit Frequency	Nutritional Monitoring	Key Recommendations
AACE/ASMBS [3]	Lifelong follow-up recommended	Frequent visits during the first postoperative year; periodic long-term follow-up	Routine monitoring of iron, vitamin B12, folate, vitamin D, calcium, and other micronutrients	Lifelong supplementation; multidisciplinary follow-up recommended
EASO/EAES [25]	Lifelong follow-up recommended	Regular follow-up during the first year; ongoing long-term surveillance	Nutritional and metabolic monitoring according to procedure	Structured postoperative pathway including dietary, psychological, and medical support
BOMSS (UK) [48]	Lifelong follow-up recommended	Bariatric center follow-up for first 2 years; annual monitoring thereafter	Detailed biochemical monitoring protocol including micronutrients	Structured laboratory surveillance and standardized micronutrient supplementation
KSMBS [49]	Lifelong follow-up recommended in principle	Follow-up schedule varies by institution	Perioperative micronutritional monitoring recommended	Multidisciplinary follow-up encouraged

MBS = metabolic and bariatric surgery, AACE = American Association of Clinical Endocrinology, ASMBS = American Society for Metabolic and Bariatric Surgery, EASO = European Association for the Study of Obesity, EAES = European Association for Endoscopic Surgery, BOMSS = British Obesity and Metabolic Surgery Society, KSMBS = Korean Society for Metabolic and Bariatric Surgery.

EFFICACY AND NECESSITY OF MULTIDISCIPLINARY FOLLOW-UP

Given the multifactorial nature of obesity, multidisciplinary follow-up has become an essential component of postoperative care after MBS. Although surgical procedures effectively induce weight loss, long-term outcomes are also influenced by dietary adherence, behavioral modification, metabolic control, and psychological well-being [51,52]. Consequently, comprehensive follow-up often requires collaboration among surgeons, physicians or endocrinologists, dietitians, mental health specialists, and exercise professionals [3,25]. Previous studies have shown that multidisciplinary follow-up is associated with improved weight maintenance, better metabolic outcomes, and a reduced risk of nutritional deficiencies [25,53,54]. In addition, regular involvement of dietitians and mental health professionals may help address maladaptive eating behaviors, psychological distress, and lifestyle factors that contribute to weight regain [51]. However, implementation remains inconsistent across institutions due to limitations in resources and healthcare infrastructure. These findings underscore the need for integrated and sustainable multidisciplinary care models to optimize long-term outcomes after MBS.

CONCLUSION

Long-term follow-up is a fundamental component of successful MBS and plays a critical role in maintaining durable weight loss, preventing nutritional deficiencies, and managing metabolic outcomes. However, adherence to follow-up remains suboptimal due to a combination of patient-related, structural, and healthcare system barriers. Current clinical guidelines consistently emphasize the importance of lifelong surveillance with regular clinical assessment and nutritional monitoring. In addition, multidisciplinary care models involving surgeons, physicians, dietitians, and mental health professionals are increasingly recognized as essential for comprehensive postoperative management. Future efforts should focus on developing structured and sustainable follow-up strategies to improve long-term adherence and optimize patient outcomes after MBS.