Bariatric surgery decision-making of adults with obesity: a grounded theory study

Abstract

Objective

The retention rate of Bariatric Surgery (BS) remains a critical concern, yet the decision-making mechanism among obese individuals considering BS is still unclear. This study aims to identify key stages and core mechanisms in the BS decision-making process.

Design

Qualitative, one-on-one, and focus group in-depth interviews were conducted.

Methods

Semi-structured interviews were conducted in China from September 2022 to February 2023. Using the Straussian Grounded Theory (SGT) approach, an iterative analysis of the BS decision-making process was performed, ultimately constructing a decision-making mechanism for obese patients opting for BS. Reporting followed the SRQR checklist.

Results

Interviews were conducted with 21 obese individuals scheduled for BS one day before surgery. A theoretical model was developed to describe and explain the BS decision-making process. The study identified five key stages in the decision-making process: Initial Attention, Proactive Information-Seeking, Decision-Making Process, Definitive Surgical Decision, Preparation Phase, and Abandonment, with the Decision-Making Process being the most critical. The study examined the influence of External Environment on Cognitive Decision-Making, focusing on social pressure, social support, and peer support. Additionally, the Cognitive Trade-off Theory for Bariatric Surgery (CTT-BS) was established, incorporating five cognitive-level factors.

Conclusion

The identified decision-making stages and cognitive theory provide evidence to clarify the facilitators and barriers to BS motivation retention, offering insights for developing strategies to improve BS retention rates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-025-24035-x.

Introduction

The statistics released by the Chinese government in 2022 reveal a significant upward trend in the prevalence of overweight or obese individuals, with over 50% of adults and nearly 20% of children affected [1]. According to the latest research projections [2], by the year 2030, it is estimated that 65.3% of Chinese adults (≥ 18 years old) will be overweight or obese, amounting to approximately 790 million people. In the adult population, BS has been firmly established as the most effective treatment option for sustained weight reduction and the mitigation of obesity-related complications [3–5]. Furthermore, BS holds crucial significance in enhancing the quality of life and overall experiences for obese adults [6].

In contrast to the established safety and efficacy of BS, its utilization rate remains remarkably low [7]. As of October 2021, despite the total number of surgeries exceeding 10,000 according to the Chinese metabolism and BS database, studies indicate that the annual percentage of individuals meeting the criteria for BS and undergoing the procedure is among the lowest globally, approximately 0.01% [8], which is only around one-tenth of the rate in the United States [9]. Addressing the issue of low utilization and improving retention rates for BS is a shared global challenge.

Existing qualitative studies have primarily focused on descriptive analyses of attitudes and perceptions toward BS among various populations with obesity, while few have systematically explored the underlying mechanisms influencing decision-making regarding the acceptance of BS. To date, only two studies have explicitly examined decision-related barriers to undergoing BS. Luke et al. [10] investigated systemic barriers to referral and uptake of BS from the perspectives of veterans with severe obesity and their healthcare providers, whereas Eric et al. [11] explored cognitive barriers among adolescents. Although both studies provide valuable insights into facilitators and barriers from specific dimensions, they fall short of adopting a comprehensive perspective on the entire decision-making process and its underlying mechanisms. This limitation reduces their practical utility for clinical guidance. Therefore, in-depth interviews and analyses of the preoperative decision-making process for BS are warranted to elucidate the decision stages and influencing mechanisms, which holds significant research value.

Unlike the institutional framework in the United States, obese individuals in China do not undergo a multi-departmental, hierarchical assessment process for BS. They can independently choose a trusted hospital and doctor, and after completing the preoperative assessment, arrange the surgical procedure. Therefore, the phenomenon of low utilization of BS is less related to systemic constraints and more associated with obese individuals choosing not to pursue weight reduction through surgery for various reasons. Clearly understanding the decision-making mechanisms can provide insights into both facilitating and hindering factors, aiding individuals in smoothly navigating the decision-making process. This is particularly relevant in the Chinese healthcare context and serves as a prerequisite for future efforts to increase the utilization of BS.

To address the gap in understanding the decision-making process for BS, this study employed a constructivist grounded theory approach to explore how individuals with obesity navigate decisions regarding BS. Based on the qualitative data collected, we developed a new theoretical model that delineates the key stages of BS decision-making and the underlying mechanisms that shape patients’ choices. This model was not adapted from existing frameworks, but rather emerged inductively from participants’ experiences, offering a novel perspective that extends the current theoretical understanding of health-related decision-making in the context of obesity treatment.

Methods

Aim

This study aims to develop an integrated empirical-theoretical framework to systematically elucidate the dynamic process through which patients progress from initial motivation to final surgical decision-making. The specific objectives are: (1) to delineate the stage-specific characteristics and critical transition points in BS decision-making; (2) to identify the key stakeholders (e.g., patients, family members, healthcare providers) and their interactive factors (psychological, social, clinical, etc.) at each decision-making stage; and (3) to construct a multilevel theoretical model that reveals how synergistic or antagonistic mechanisms among these factors drive progression across stages.

Study design

This study employs the Straussian Grounded Theory (SGT) method developed by Strauss and Corbin [12]. Compared to other grounded theory approaches, SGT permits researchers to appropriately incorporate existing theories during the axial coding phase to facilitate the identification of relationships between categories. Although no mature theoretical model directly explains the research problem under investigation, core constructs from the Health Belief Model (HBM) [13] and Protection Motivation Theory (PMT) [14] provide heuristic references for identifying key categories in the decision-making mechanism (such as the interaction between “perceived threat” and “self-efficacy”). We adhered to the Standards for Reporting Qualitative Research (SRQR) as a guide to guarantee the quality of our reporting(see Appendix S1).

Sampling and recruitment

This study employed theoretical sampling in accordance with grounded theory methodology. Explicit inclusion criteria were defined: participants had to be at least 18 years old, be fluent in Mandarin, be scheduled to undergo BS the following day, and provide informed consent voluntarily. The sampling process was systematically carried out in three sequential phases.

In the initial open sampling phase, we deliberately selected female patients aged 25–35 as initial interviewees. This demographic tended to have stronger verbal communication skills, greater emotional expressiveness, and better compliance with in-depth interviews. Open coding of early interviews led to the identification of preliminary core concepts such as perceived threat, social support, and stigma experience.

During the differential sampling phase, aimed at theory development, we broadened the sample to enhance diversity across demographic and social dimensions. This included variations in gender and age, as well as marital status, occupational background, and geographical origin. For example, we recruited male corporate executives who exhibited pronounced decision-making trade-offs, and unmarried females with prominent appearance-related concerns.

In the theoretical saturation phase, we purposefully selected extreme or atypical cases to test and refine the emerging theoretical framework. Termination criteria included: (1) no emergence of new conceptual attributes across three consecutive interviews, (2) stabilization of theoretical relationships among categories, and (3) formation of a coherent and saturated theoretical narrative. Ultimately, a total of 21 participants were enrolled, reaching theoretical saturation.

During implementation, one scheduled participant withdrew due to an unexpected ward incident (a collapsed bed rail). A substitute participant with comparable sociodemographic characteristics was recruited. All participants provided written informed consent after receiving a full explanation of the study’s objectives, potential benefits, and risks. Confidentiality was strictly maintained, and participants were assured of their right to withdraw at any time without consequences to their clinical care.

Data collection

Data collection and analysis were conducted concurrently and iteratively, in accordance with grounded theory methodology. Semi-structured interviews were guided by a researcher-developed protocol, comprising predominantly open-ended questions supplemented by a few closed-ended items. The interview guide was refined through expert consultation with bariatric surgeons and qualitative research specialists. Prior to formal data collection, pilot testing was conducted with three participants, whose data were ultimately retained for analysis.

Between September 2022 and February 2023, two researchers conducted face-to-face interviews with 21 patients who had made the decision to undergo BS. The study employed a micro-focus group design (2 participants per group, n = 3 groups), which effectively captured peer interaction dynamics while mitigating the “dominant voice” effect commonly observed in larger groups, all while controlling for privacy risks associated with obesity stigma—a critical consideration for bariatric surgery decision-making research.Theoretical sampling guided recruitment, and the interview guide was continuously adapted in response to emerging themes. Additional questions were incorporated throughout the data collection process to explore relevant topics in greater depth and to probe newly identified concepts. Toward the end of each interview, researchers posed a final open-ended question to encourage participants to share any additional insights.

Seventeen interviews were conducted in a quiet meeting room. One focus group was held in a patient ward due to participant constraints. Interviews ranged in duration from 30 to 90 min. All sessions were audio-recorded.

The primary interviewer (first author) is a health promotion scholar-practitioner with extensive experience in qualitative research. Her affiliation with the medical institution—but not with the surgical team—helped establish participant trust while potentially minimizing social desirability bias. Researchers recorded field notes to capture participants’ nonverbal cues. All transcripts were rigorously de-identified to ensure confidentiality. The complete English version of the interview guide is available in Supplementary Material 1.

Data analysis

Prior to conducting qualitative analysis, the research team first compiled and summarized participants’ socio-demographic characteristics. This study employed Straussian Grounded Theory (SGT) [12], following a systematic coding process of open coding → axial coding → selective coding to analyze semi-structured interview data and construct a decision-making mechanism theory.

The coding team (YHX and WL) initiated the analysis, with SND subsequently joining for verification, while HYP provided theoretical guidance and resolved discrepancies throughout the process. During the open coding phase, researchers conducted preliminary, exploratory, and flexible analysis of textual data to identify diverse phenomena and concepts. Subsequently, through axial coding, the team systematically integrated initial concepts, analyzing their attributes, dimensions, and interrelationships to progressively develop a structured hierarchical category system. At this stage, we appropriately incorporated key constructs from the Theory of Planned Behavior, Protection Motivation Theory, and General Deterrence Theory as heuristic frameworks to enhance the explanatory power of category relationships. For example, “perceived threat” was treated as a causal condition and “social media information” as a contextual condition to understand their combined influence on the formation of behavioral intentions.During the selective coding phase, the research team focused on the most explanatory core categories related to the research questions, further integrating analytical results to ultimately develop a coherent, in-depth, and theoretically saturated model of preoperative decision-making mechanisms for BS.The coding examples are shown in Fig. 1.

Fig. 1.

Illustration of the analysis process moving from transcript extract to Selective codes

SGT remains fundamentally inductive in nature, and this study strictly adhered to this logic: open coding relied entirely on emergent data, while axial coding leveraged researchers’ theoretical sensitivity (i.e., utilizing existing knowledge structures and professional expertise to discern deeper connections within the data) to moderately incorporate external theories and enhance the interpretative depth of category integration. In practice, we followed the conditional matrix method proposed by Strauss & Corbin [12] to ensure that theories served only as auxiliary explanatory tools rather than a priori frameworks, thereby avoiding forced interpretations of the data.

To ensure research reliability and the validity of theoretical construction, the research team implemented negative case analysis, member checking, and the constant comparative method to continuously verify and refine emerging categories and theoretical structures.Additionally, NVivo 12 computer-assisted qualitative data analysis software was used to facilitate data organization, coding, and tracking management, ensuring the systematicity and traceability of the analytical process.

Rigour and trustworthiness

To ensure the rigor and credibility of this study: (1) Five researchers engaged in data collection or analysis, ensuring comprehensive research involvement. (2) We continuously scrutinized our assumptions and theories, adjusting and refining our theoretical framework. This ongoing reflexivity mitigated subjective biases and enhanced pattern discernment within the data. (3) We maintained an open stance towards data collection methods, including one-on-one interviews and focus group discussions. (4) Throughout data collection and analysis, each data collector and analyst possessed a thorough understanding of the study’s background and context.

Results

Twenty-one patients intending to undergo BS were interviewed one day before the operation. All interviewed participants ultimately underwent the surgery. Demographic details of the participants are presented in Table 1.

Table 1.

Summary of interviewee demographics (N = 21)

Demographics	N = 21
	N(%)
Age
18–20	1(4.8)
21–30	7(33.3)
31–40	13(61.9)
Gender
Male	6(28.6)
Female	15(71.4)
marital status
single	7(33.3)
married	13(61.9)
divorced	1(4.8)
BMI
31.1–40.0	11(52.4)
40.1–50.0	8(38.1)
50.1–60.0	1(4.8)
60.1–70.0	1(4.8)
The number of comorbidities
3	2(9.5)
4	8(38.1)
5	5(23.8)
6	5(23.8)
> 6	1(4.8)
surgical method
laparoscopic sleeve gastrectomy (LSG)	17(81.0)
laparoscopic sleeve gastrectomy with jejunojejunal bypass (LSG-JJB)	4(19.0)

Through qualitative analysis, we identified 34 categories that comprehensively reflect the stages, actions, and factors that regulate the dynamic interplay between different phases in the BS decision-making process. An independent coding manual (see Supplementary File 2) provides a complete list of all subcategory names, conceptual examples, definitions, and category relationships. The core category, BS Decision-Making, serves as an overarching concept that integrates these categories into a coherent framework.

Our findings suggest that the decision-making process of individuals with obesity regarding BS can be understood as consisting of six interconnected and non-linear heuristic stages, influenced by five overarching factors. As illustrated in the theoretical framework (Fig. 2), Initial Attention marks the entry point into the decision-making process, and Proactive Information-Seeking represents a critical and inevitable phase. The Decision-Making Process, as the central stage, can lead either to a Definitive Surgical Decision or Abandonment, but may also cycle back to the information-seeking phase—highlighting the iterative nature of this process. Notably, both the decision to proceed with surgery and the decision to abandon it are not irreversible; individuals may re-enter the decision-making process when conditions are perceived as inadequate or uncertain.

Fig. 2.

A theoretical framework of Decision-Making for BS

The Preparation Phase, while typically following a surgical decision, was empirically found to be re-accessible from any stage—even as late as 24 h before surgery. Transitions between stages and behavioral expressions within each phase are essentially shaped by the interplay of personal factors (e.g., attitudes, self-efficacy, perceived response cost), environmental factors (e.g., accessibility of medical resources), and social factors (e.g., weight stigma, public awareness of BS). The following sections provide a detailed description of each phase, its associated categories, and influencing factors. Additionally, as the central stage of the entire theoretical framework, the decision-making process plays a pivotal role. Based on our data analysis, we further examined the interrelationships among its core concepts. The results of this analysis are also presented in the following sections.

Initial attention phase

The Initial Attention to BS among individuals with obesity is primarily driven by the physical and lifestyle challenges associated with obesity, repeated failed weight-loss attempts and observational learning stimuli (e.g., witnessing the outcomes of others’ surgeries). Progression to the Proactive Information-Seeking stage is triggered by several key factors, including: personal experiences of weight-based stigma, infinite scroll reinforcement on social media (i.e., continuous exposure to surgery-related content), and the doctor’s initial recommendation (the first authoritative medical suggestion received).Notably, while some individuals are able to move into the Proactive Information-Seeking stage even without clear triggering factors, others require such stimuli—such as weight-based stigma or social media exposure—to initiate this transition. Those who remain in the Initial Attention stage typically exhibit passive absorption of fragmented information and a lack of systematic efforts to seek out or evaluate relevant content.

Intense desire for weight loss-challengers posed by obesity

The impact of obesity on physical health is undeniable, and a majority of the respondents discussed various physical discomforts resulting from obesity or directly leading to the onset of diseases. Female participants additionally expressed dealing with irregular menstruation, polycystic ovary syndrome, and fertility challenges.Participant 18: “My period is irregular.My blood pressure tends to run a bit high, not quite hitting the hypertension mark, but it’s on the elevated side.I get tired easily, and my mental game is not top-notch. For instance, if we both put in 8 hours at work, you might think it’s okay, but I’d find it pretty exhausting.”

Obesity poses myriad challenges to respondents’ daily lives and social interactions. Reduced agility and mobility hinder routine tasks like grooming, dressing, using restrooms, and navigating stairs. Weight restrictions at recreational facilities, like amusement parks, bar their participation. Plus-size clothing complicates shopping and increases travel expenses due to preferences for business-class seats. Physical limitations also lead to a higher likelihood of declining social invitations.Participant 10: “Now, I can’t even reach my toenails when it’s time to trim them. I have to wait until my husband has some free time to help because I can’t bend over, and if I do, it gets uncomfortable with my belly in the way.”

Most respondents are deeply dissatisfied with their obesity, expressing a desire for a slimmer appearance. They’ve become more self-conscious and may even experience anxiety or depression due to encountering unfair treatment in their personal or professional lives because of their weight. If these biases and lack of acceptance come from loved ones or family members, it can destabilize their emotional, marital, and parent-child relationships. Single individuals often face repeated setbacks in their search for a romantic partner due to such biases. Participant 9: “Then, when you go to the kindergarten, I remember very clearly, my daughter used to come to me and say, “Mom, the other kids’ moms wear dresses and have long hair. When are you going to grow your hair and wear a dress? Isn’t she saying other moms look pretty?"She said, “Mom, don’t wear this outfit to my school tomorrow”.”

Failed weight-loss attempts

Exercise or physical activity is frequently employed as a weight loss method. However, individuals with a considerable initial body weight often face challenges continuing due to physical constraints, such as stress on the spine and knees. Additionally, some individuals discontinue this approach due to perceived inefficacy.In addition to the aforementioned challenges, weight loss camps also need to consider rebound weight gain and time costs.Participant 16:“If you’re 400–600 pounds, going for a run or jumping rope feels like signing your own death warrant. It’s basically putting your knees through torture every day. Because, you know, for heavy folks, doing exercises like running or jumping rope is seriously brutal on the knees. Basically, you can’t count on stuff like running or jumping rope, those aerobic exercises, to lose weight.”

Dieting or controlling one’s diet is frequently tried as a weight loss method, but many obese individuals struggle to maintain it long-term. Short-term adherence can result in weight rebound. Dieting often leads to low energy levels, impacting daily life and activities, and may decrease overall life satisfaction. Participant 4:“Because people feel it’s just not fun, you know? They’re all into eating flavorful and spicy stuff, and the kids are constantly munching on sweets. Then they ask the teacher, “Why aren’t you eating? Are you sick?” And you start thinking, “If you can’t even enjoy good food, what’s the point of living?“”.

Cupping and acupuncture, traditional Chinese medicine techniques, are commonly discussed. However, individuals who have attempted them express concerns about the pain and discomfort, hindering their perseverance. Those who haven’t tried these methods worry about the qualifications of traditional Chinese medicine clinics. Participant 9:“And then there’s that acupuncture weight loss thing. I mean, you don’t even have a proper medical license, and you want me to lie down and let you stick needles in me? Forget it, right? It’s like some backyard operation, or one of those pyramid schemes. You walk in, they shut the door, and you lie there while they do whatever they want.Nah, I’m not going for that. I just can’t accept it. They don’t even have a qualification certificate. If something goes wrong, who am I supposed to hold accountable?”

Observational learning stimuli

Many respondents initially had no knowledge of BS. The first time they heard about it was through people around them, influencers they follow, or celebrities who had undergone BS and achieved impressive results. This gave them a positive first impression of BS, sparking their interest in this method of losing weight.Participant 2:“She was the first surgical patient of Dr. [X] last year, and Dr. [X] attended her wedding last night. When I saw this girl, I was like, I don’t know how to describe it. Anyway, at that moment, seeing the before-and-after videos, I just thought I must make up my mind to undergo the surgery.”The successful weight loss experiences of others through BS can have a profound impact on individuals struggling with obesity, especially when the person sharing the experience is someone close to them. The role of such a role model not only captures their attention towards weight loss but may even lead some individuals to make a direct decision to undergo BS.

Weight-based stigma

Almost all individuals with obesity reported experiencing varying degrees of weight stigma throughout their lives. These experiences primarily manifested as weight-related teasing, social gossip, hyper-vigilant scrutiny, weight-based attribution bias, and unfair treatment. As participant 17 described: “It’s like they turn your weight into a kind of humiliation—as if being fat automatically means you’re lazy, you have no self-discipline, like it’s some kind of personal failure. It feels like an attack on who you are. And the thing is, you don’t even know these people, you’ve never done anything to them, but they act all superior and judge you like they’re better than you.”

Infinite scroll reinforcement: algorithm-driven content bombardment

In China, short video platforms are widely popular. The repetitive browsing behavior of obese individuals on these platforms regarding topics related to obesity and weight loss is captured by big data, resulting in a continuous influx of content introducing and promoting BS to users. This extends to direct promotions from professional weight loss surgeons. The frequent appearance of these short videos in the view of the obese population acts as a lure, influencing their decision-making process regarding BS.As Participant 3 described:“After getting into this, I think big data is pretty impressive nowadays, you know? I mean, the push notifications cover weight loss surgeons from all over the country. On TikTok, I’m getting pushed content from weight loss surgeons everywhere, from the south like Nanjing and Chongqing, to places like Chengdu, and even down to Guangzhou in the south.” Participant 17 also describe:“Because I’m always scrolling through stuff related to weight loss, you know? Like diet plans, and then there’s this weight loss boot camp thing. The big data related to it, it just throws recommendations at you. Some are about weight loss surgeries, the pros and cons of getting one, and all that kind of stuff.”

Doctor’s initial recommendation

While recommendations from healthcare providers relatively less frequently spark interest in BS, the credibility associated with doctors and medical institutions remains crucial in guiding the attention of the obese population towards understanding such procedures.Participant 12: “The doctor over in our local area recommended me to go for a weight loss surgery. That’s when I first found out about this whole weight loss surgery thing. But at that time, nobody around me had done it, so I thought I’d come and get some advice.”

Proactive information-seeking

Most obese individuals don’t rush into surgery upon initially learning about BS. Instead, when something triggers their interest in BS, they typically enter a prolonged observation period. During this phase, they gather information about BS, providing a crucial foundation for subsequent decisions regarding such procedures.The information proactively sought by participants primarily included surgical efficacy, types of procedures, criteria for selecting a surgeon, operative risks, potential postoperative complications and perioperative precautions, cost and insurance coverage, use of postoperative pain pumps, follow-up protocols, dietary guidelines, expected recovery timelines (including return-to-work plans), patient-reported outcomes, the probability of weight regain, and concerns about skin laxity caused by rapid weight loss.

Healthcare providers

Obese individuals primarily interact with doctors through fan groups on short video platforms, weight loss surgeons’ responses in online forums, private online conversations with doctors, and scheduling face-to-face consultations. Directly acquiring information from healthcare professionals ensures access to authoritative information. Their inquiries mainly focus on surgical methods, success rates, risks, costs, and indications. Participant 9: “Basically, I’ve read a lot of their responses in the background. It’s really worthwhile to take a day and come in person to ask questions. While chatting online is fine, for serious matters, I think it’s necessary to have a face-to-face conversation. That’s how I see it.”

Multidimensional online information

When seeking online information, individuals grappling with obesity typically favor educational content, especially if provided by healthcare providers, to grasp the intricacies of weight loss surgeries. Actively seeking user feedback, they gain insights into surgical complications, postoperative discomfort, and detailed postoperative precautions or experiences. However, some respondents noted the need for longer follow-up periods in user feedback to observe outcomes over extended postoperative timeframes.Participant 3: “There’s this medical website where, you know, they kind of have those specialized topics, and they publish stuff. So, I check that out. And there’s also this video overview of the surgery.”

Peers or weight loss buddies

Obese individuals in this stage prefer to gather detailed information about BS from examples or peers. This includes whether accidental surgery insurance is necessary, preoperative preparations, and postoperative precautions, rather than solely focusing on stark contrasts in weight loss outcomes.Unlike other sources of information, peers can provide real-time and highly detailed feedback.Participant 4: “They (those who have undergone the surgery) just said there’s absolutely no problem. They were quite straightforward and told us upfront that there’s no need to buy preoperative insurance, and Dr. [X]’s skills are top-notch. Then they mentioned that there were basically no issues at all; you sleep for a while, wake up, and everything’s fine. They also mentioned that regarding the pain relief pack, it depends on individual tolerance; basically, you might not even need it.”

Decision-making process

Attitudes

Based on differences in their information acquisition, as well as their own obesity conditions, complications, and weight loss experiences, obese individuals develop varied attitudes towards BS. For a significant portion of participants, surgery is seen as a final opportunity—a top choice that is viewed as the sole and scientifically reasonable method for addressing the fundamental issue of weight loss in their current circumstances. Participant 1: “Surgery is currently the best option because I feel stuck in a vicious cycle.” Yet, some still perceive BS as a shortcut for rapid weight reduction. Participant 12: “My friends, including other girls, say this is really good, and you don’t need to take pills or do much, you know? She says you don’t even need a lot of exercise.” While some participants consider obesity as a disease or the root cause of diseases, viewing BS as a means to achieve health rather than just weight reduction. Participant 15: “Starting this year, I felt it was necessary to go through with this (BS). For me, not having this done might mean losing my health.” Others regard it as a form of medical aesthetics—a pathway to pursue a more ideal image rather than a therapeutic measure. Participant 3: “I think most of them are women, more focused on getting slim, you know, primarily for the sake of looking good. They basically see this surgery as a form of medical aesthetics, but it’s okay.” In this study, half of the participants viewed BS as a means of restraint. They utilize postoperative food intake restrictions and the potential complications after surgery to control their appetite and dietary behaviors, aiming to compensate for what they perceive as a lack of willpower.Participant 2: “The risk of sneaking in a cheat meal for her postoperatively is stomach leakage, which can be life-threatening. I can’t joke about my own life, so I have to force myself in this way.”

Self-efficacy

The majority of respondents have shown strong self-efficacy regarding BS, indicating their confidence in meeting the requirements for the procedure. They also display assurance in areas like the surgery itself, postoperative lifestyle changes, and dietary management. Their belief in sustaining these changes and reaching weight loss goals greatly influences their decisions regarding BS. Participant 8: “Because I don’t have any other health issues. So, I don’t really have any other concerns. Maybe those who have other complications might worry a bit more or consider more factors.” Participant 4: “Back in the day, if I felt happy, I might just grab some fried chicken and have a drink. But moving forward (post-surgery), I probably won’t do that anymore. I’ll start steering towards a healthier lifestyle on my own.”

Response efficacy

Based on the information acquired in the earlier stages, nearly all participants acknowledge the efficacy of BS. They firmly believe that undergoing BS will enable them to achieve postoperative weight reduction, reach their anticipated weight goals, and, in turn, experience improvements in health and enhanced quality of life.Participant 5: “I think it should work out fine. Among the numerous surgeries I’ve heard about, there hasn’t been any negative outcome unless someone didn’t follow the doctor’s advice. ” Participant 9: “Gastric cutting can get me to where I want (to lose weight).”

Response cost

Cost is a significant consideration in surgical decision-making, with some individuals opting out of surgery due to its high expense. Most participants compare BS costs across different regions within the country and even internationally to ensure the chosen hospital’s fees are reasonable. Participants also factor in potential costs associated with postoperative recovery and specialized dietary requirements. For the majority, belief in the value of BS is rooted in perceived response efficacy. Additionally, they compare BS costs to alternative weight loss methods or other daily expenses to justify it as a worthwhile investment.Participant 3: “Not too expensive, just the cost of a bag—skipping one bag purchase. Compared to spending money for years without getting slimmer, it’s definitely worth it.”

When considering the time commitment for BS, individuals focus on scheduling and availability for surgery appointments, as they must set aside time for the procedure. The recovery period following surgery is also critical, as obese individuals are curious about when they can return to their regular life and work activities. This aspect sometimes plays a direct role in their decision to undergo surgery. Participant 19: “After the surgery, approximately when can the body return to normal? Because I don’t want it to affect my work. If it requires heavy physical activity, I might reconsider. I’ll need some time for recovery, but I don’t have that much time to rest.” Participant 7: “If I had waited for the regular schedule, it might have been scheduled for October, which seemed a bit late for me.”

Perceived threat

Most respondents thoroughly assess the risks involved, considering factors like surgical risks, the consequences of not having surgery, weight regain risk, and rapid weight loss risk. They evaluate both their vulnerability to risk and its severity. While perceptions of risk severity vary, most individuals believe they are not the exception in terms of susceptibility.

Surgical risks are a major concern for nearly all participants, involving potential post-surgery discomfort and complications. While many express worry, most believe the likelihood of these risks is low and won’t affect them personally. Some are willing to accept some risk for a transformative outcome. However, some individuals are hesitant to explore postoperative risks, fearing that this knowledge could cause unnecessary anxiety and disrupt their decision-making. Others trust the procedure’s sophistication and the surgeon’s expertise, seeing it as largely risk-free. Yet, some still worry about long-term impacts.Participant 10: “I’m worried, you know, after I’ve done the surgery, what if there’s a leak in the stomach or the stitches aren’t done right? Or what if later on, they say it’s stomach cancer and stuff like that? If it’s stomach cancer, and my stomach is perfectly fine now, can they still cut a bit, maybe leave some there? But after getting weight loss surgery, they’ve cut it down quite a bit. What if there’s another issue, like, say, stomach cancer or something, can they still cut? I mean, there’s not much left to cut now, and I’m just always worried about that.”

Participants consider the risks associated with not undergoing surgery.Most respondents believe achieving their weight loss goals would be difficult without surgery. They foresee potential consequences of forgoing surgery, including complications, physical discomfort, a shorter lifespan, reduced quality of life, and potential dependence on others for care, affecting their families. Female participants also worry about fertility issues. Interestingly, many perceive the risks of not having surgery as higher than those of undergoing it, likely due to their deep understanding of obesity’s complexities.Participant 6: “But moving forward, it’s definitely going to lead to a lot of subsequent health issues, and I’m aware of that. Plus, I’m thinking if I keep getting this overweight, I’ll end up being a burden on my kids.”

For individuals undergoing BS, the paramount concern is weight regain, reflecting their acute awareness of its seriousness and strong determination to prevent it. This apprehension also highlights their anxiety about maintaining self-discipline, fearing a resurgence of body weight due to difficulty in sustaining healthy dietary habits, possibly requiring a second surgical intervention in extreme cases. Participant 11: “(Post-surgery) I feel like there still needs to be control, including diet and all that. Exercise is necessary too. I definitely don’t want to end up getting all chubby again, you know?”

The strong response efficacy to BS convinces obese individuals that there is a high probability of experiencing rapid weight reduction post-surgery.However, their concerns extend beyond mere weight loss, particularly focusing on potential skin laxity. They’re actively taking steps to address this risk. Participant 3: “Just looking at how slim I’ve become, I’m worried about loose skin.”

Anticipated benefits

The anticipated benefits revolve around successful weight reduction, envisaging an improved appearance post-BS. A better image motivates individuals to dress more attractively, potentially altering perceptions. They anticipate newfound opportunities in activities, employment, and relationships, ultimately enhancing self-worth. Participant 4: “ I’m also thinking about the fact that my child is now in high school, and I’m hoping that when she takes the college entrance exam, I can wear a beautiful qipao just like she did during her own exam.”

Successful weight loss helps prevent various health issues linked to obesity, fostering a healthier body, improved mental well-being, and a longer lifespan. This enables better fulfillment of familial responsibilities and enhanced companionship with loved ones. Notably, female individuals grappling with obesity look forward to the possibility of fertility. Participant 7: “ She said this (weight loss surgery) does work, and she hadn’t even had children before, but afterward, she had kids as well. That also gave me a lot of confidence.”

Certainly, the most noteworthy emphasis lies in their aspiration to become more self-assured, as obesity has engendered feelings of inferiority. Participant 4: “ People also feel like they can be a bit more confident. It’s like having a chance for a rebirth, a kind of transformation that truly allows us to be more self-assured.”

Mechanism of the decision-making process

Based on the hierarchical coding and theoretical analysis of the research findings, and in order to maintain conceptual parsimony, we adopted the following strategies: (1) The theoretical framework presents the results from two key perspectives—the pathways through which the external environment influences cognitive decision-making, and the interactions among core cognitive variables. (2) During model integration, we excluded the variable of anticipated benefits. Although anticipated benefits (e.g., improved appearance, enhanced health outcomes) are important considerations in the decision-making process, they are subsumed under the broader construct of response efficacy in our model. The patient’s level of trust in the surgical outcome (i.e., response efficacy) directly influences the strength of anticipated benefits, indicating a causal continuity between the two.

The influence mechanism of the external environment on cognitive decision-making

Our study found that the external environment influences decision-making primarily through social pressure, peer support, and family support. Although both peer and family support fall under the broader category of social support, they exert distinct influences on the decision-making process of individuals with obesity, highlighting the need to distinguish them clearly(see Fig. 3).

Fig. 3.

Three-Tiered Decision-Making Framework: Environmental, Cognitive, and Behavioral Decision Levels

First, we define social pressure as encompassing all forms of stigma related to both obesity and BS. Such pressure undeniably strengthens individuals’ threat perceptions regarding BS—manifesting in heightened concerns about the risks of surgery itself, the consequences of not undergoing surgery, and the possibility of weight regain after surgery. For instance, Participant 6 remarked:“Some people say, like, if you do this surgery and have part of your stomach removed, what if something else goes wrong in your body? What if they find some other problem?”

Another key finding of our study is that social pressure modulates self-efficacy through a dual-pathway mechanism. The direction and intensity of this influence are shaped by the degree of internalized stigma and the availability of supportive resources. High-frequency exposure to social pressure often leads to stigma internalization, prompting individuals to turn societal bias inward and begin doubting their own capabilities. As Participant 17 reflected:“Honestly, when you’ve taken in so much negativity, you start to feel hopeless—you kind of just give up on yourself mentally.”Interestingly, we also observed a reverse effect: in some cases, social pressure actually boosts self-efficacy. Rather than being overwhelmed by stigma or negative comments, many individuals with obesity became more determined to act, showing a stronger resolve to pursue surgery and change their lives. As Participant 6 shared:“It’s like what my mom said—‘You’re so overweight, you’ve got to lose it. If you don’t, when you’re older, is it me who’s taking care of you, or are you taking care of me?’ I told her, ‘I’ll take care of you.’ So now I’m dead set on making this work.”

The enhancing effects of peer support on both self-efficacy and response efficacy have been previously established. However, its dual impact on perceived threat warrants particular attention. Peer support exerts a nonlinear influence on individuals’ perceived threat: while it can alleviate fears surrounding BS by offering reassurance and shared experiences, it can also amplify anxiety—especially concerning issues like postoperative weight regain—through exposure to others’ negative outcomes.As Participant 3 explained:“Honestly, I’m pretty worried about that too. I mean, yeah, in the first couple of years after surgery, maybe someone drops all the way down to their goal weight—but then, depending on their lifestyle, boom, they gain back like 20 or 30 pounds. That’s something I really couldn’t handle.”

This study regretfully highlights the limited role of family support within the Chinese sociocultural context. Despite achieving theoretical saturation, we found few instances in which family support meaningfully influenced self-efficacy or response efficacy. Most participants reported involving family members only during the final decision-making stage, primarily to seek approval or consent. While family members may provide some financial assistance—addressing part of the perceived response cost—their cognitive involvement in earlier stages of decision-making was minimal. However, when it comes to perceived threat, family support demonstrated a dual-channel leverage effect. On one hand, family members’ involvement in private caregiving tasks (e.g., assisting with toileting or dressing) heightened patients’ awareness of the chronic risks of not undergoing surgery, triggering self-esteem maintenance mechanisms that made hidden health threats more salient. On the other hand, deeper family engagement in medical processes (e.g., attending consultations, joining doctor-patient communication groups) produced a “demystification” effect, breaking down abstract surgical risks into manageable and understandable procedural steps, thereby reducing anxiety about surgical complications. These two opposing but complementary mechanisms constitute the cognitive pathways through which family support influences perceived threat.

Cognitive trade-offtheory for bariatric surgery

This study, grounded in a constructivist grounded theory approach, developed a model titled the Cognitive Trade-off Theory for Bariatric Surgery (CTT-BS), which positions self-efficacy at its core and identifies perceived threat as the primary driving force (see Fig. 4). The model is based on five core cognitive variables and one outcome variable (definitions of all variables are provided in Supplementary File 2). It illustrates how patients arrive at their final decisions through a process of dynamic cognitive evaluation. The central mechanisms of this model can be summarized as follows.

Fig. 4.

Cognitive Trade-off Theory for Bariatric Surgery, CTT-BS

Firstly, perceived threat, response efficacy, response cost, and self-efficacy each exert a direct influence on individuals’ attitudes toward BS. Among these, perceived threat—particularly health risks associated with obesity (e.g., joint degeneration, impaired fertility)—often initiates a cognitive evaluation of the effectiveness of BS, shaping one’s response efficacy. The more severe the perceived health consequences of obesity, the more urgent the belief in surgery as a viable solution becomes. At the same time, heightened threat perception can also affect individuals’ confidence in their ability to manage postoperative demands, that is, their self-efficacy. This influence may be bidirectional, depending on how the individual appraises the situation—it can either strengthen or undermine self-efficacy. Notably, some participants exhibited what may be termed efficacy suppression, whereby the perceived risks—such as the risks of the surgical procedure itself, the potential for weight regain, or complications related to rapid weight loss—led to a diminished sense of control, creating psychological barriers to decision-making.

Response efficacy, or trust in the effectiveness of the surgery, emerged as a central variable in the model. It significantly reshaped how individuals understood and tolerated response costs, especially financial burdens. As Participant 3 put it: “Compared to all those years of spending money and still not losing weight, this is actually worth it.” This reappraisal of cost versus benefit reinforced participants’ sense of agency and indirectly enhanced their self-efficacy. When the cost of surgery was perceived as manageable, individuals felt more confident in their ability to handle the behavioral and logistical demands of the procedure and recovery.

Crucially, self-efficacy occupies an irreplaceable and central position within the theoretical model. It not only directly predicts attitudes toward surgery, but also functions as a cognitive integrator, absorbing and synthesizing prior evaluations—including perceived threat, response efficacy, and response cost. In other words, when individuals believe they are capable of managing the behavioral, emotional, and resource-related demands associated with BS, they are more likely to maintain a positive attitude, even in the face of moderate threats or perceived burdens.

These cognitive pathways form a recursive and compensatory structure: individuals may offset low self-efficacy with high response efficacy, or tolerate higher perceived costs when threat levels are perceived as urgent. Ultimately, these interrelated cognitive factors converge to shape attitude formation, which in turn influences the behavioral decision to undergo BS.

Resource allocation: accessible and trustworthy healthcare resources

Access to medical resources emerged as a critical trigger influencing whether individuals transitioned from decision-making to surgical action. Our study found that nearly half of the participants, despite having already formed a favorable attitude toward surgery, opted to defer the procedure due to resource constraints.

They prefer hospitals closer to home for convenience and a greater sense of security. If they can’t find a suitable hospital nearby, some may delay their plans for BS. Participant 14: “ I’m not very confident about the hospitals there (in Henan); it’s too far. In Zhejiang, at least it’s my hometown, so there’s a bit of a sense of security, not that it’s a big deal, but having it in my hometown gives me some peace of mind.”

Most respondents prioritize the credibility of healthcare facilities, thoroughly researching hospitals and physicians. They trust hospitals based on factors like ranking, reputation, and past experiences. Public hospitals with high rankings, strong reputations, and widespread recognition are preferred, especially if they or their acquaintances have had positive experiences there. Conversely, they are skeptical of unfamiliar private hospitals. Participant 21: “ You know, Sir Run Run Shaw Hospital is quite well-known in Hangzhou, and it’s also quite famous in our area. Sir Run Run Shaw Hospital has a good reputation. Let me tell you, my son was conceived through artificial insemination at Sir Run Run Shaw Hospital.”

They prefer doctors with higher titles, extensive experience, and positive feedback, as it reflects the surgeon’s proficiency. Interestingly, some even consider registration fees as a measure of a doctor’s excellence. Additionally, they seek full-time specialists dedicated to BS, preferring professionals exclusively focused on this field for their surgery. Participant 7: “ I checked his profile, and he has over 800 surgeries in the last two years. Then, I looked at a case in the group, the post-surgery condition after six months to a year, and there were even commendations. ”

Definitive surgical decision

After going through a complex decision-making process, individuals with obesity may proceed to the surgical preparation phase with a confirmed intention to undergo BS. Given that all participants in this study were scheduled to receive surgery the following day, most demonstrated a high level of decisional certainty at this stage. However, instances of regression—where individuals themselves or those around them returned from the preparation phase back to the decision-making stage—were still observed. Such regressions appeared to be associated with several factors, including incomplete cognitive processing during the decision phase, lack of family support, and limited access to essential resources such as financial, informational, or medical support.Participant 14: “But after thinking it through, I feel certain that I have to slim down, and nothing else matters. Other people’s opinions, whether it’s my girlfriend’s opposition in the past or anyone else’s, don’t matter now. Nothing will stop me from going through with the surgery.”

Preparatory phase

After deciding on BS, patients enter a preparatory phase before the procedure. During this time, they seek support from family or friends, finding significant psychological comfort in their understanding. They also gather necessary supplies for the surgery. Interestingly, some adopt a “retaliatory diet” just before the surgery, preparing themselves for the dietary adjustments post-surgery.Notably, this study also observed instances of individuals regressing from the preparation phase back to the decision-making stage. In some cases, participants even chose to withdraw from the surgical process during preoperative hospitalization by initiating discharge procedures.Participant 4: “Family support is crucial. Without it, the pressure can be overwhelming. On the other hand, with support, we feel more open-minded, perhaps more confident, and it seems like things will naturally fall into place. ” Participant 8: “I didn’t do much, just indulged in eating. I went all out and had things I wanted to eat, like hot pot and milk tea, without restraint. I thought, since I’m going to have the surgery and will lose weight afterward, and won’t be able to eat freely, I might as well enjoy eating a bit more now while I still can. Just like that.”In China, preoperative weight loss is typically not required for individuals undergoing BS, leading to a phenomenon of retaliatory eating behaviors after deciding on surgery. However, this does not mean that participants will continue unhealthy eating habits post-surgery.

Abandonment

We identified three distinct patterns of abandonment in the BS decision-making process: (1) abandonment after consultation (did not proceed with surgery after initial consultation), (2) abandonment after hospitalization (canceled surgery after being admitted), and (3) prolonged hesitation (remained in long-term indecision).

These abandonment behaviors, while differing significantly in their timing and duration, all demonstrate that patients may disengage from the decision-making process when substantial imbalance occurs in their cognitive appraisal systems. Specifically, when patients’ evaluations of perceived threat, response efficacy, response costs, and self-efficacy become significantly misaligned, they may choose abandonment as an adaptive psychological response to maintain cognitive equilibrium.

Discussion

Stages

Tolman’s purposive behavior theory [15] was the first to challenge the linear model of behavioral decision-making by introducing the concept of cognitive maps, which emphasized the interaction between environmental cues and internal expectations. This laid a theoretical foundation for understanding the nonlinearity of complex decisions such as medical treatment selection. Building upon this, Roberson et al. [16] introduced the concept of a “threshold”—a critical point at which obesity-related complications begin to shift individuals toward considering BS. Murtha et al. [17] further elaborated on this threshold model by emphasizing its significance in the BS decision-making process and by introducing the notion of “decision timing.” These concepts collectively laid the groundwork for the six-stage decision-making framework identified in this study.

Our findings suggest that the BS decision-making process involves six chronologically ordered but non-linearly connected stages: Initial Attention, Proactive Information-Seeking, Decision-Making Process, Definitive Surgical Decision, Preparation Phase, and Abandonment. Among these, the Decision-Making Process, Definitive Surgical Decision, Preparation Phase, and Abandonment stages all exhibit varying degrees of reversibility or regression. The Decision-Making Process serves as the central and most cognitively intense phase. When individuals encounter a “cost-benefit evaluation stalemate”—a state in which perceived risks, costs, and expected benefits are inconclusive or conflicting—they tend to revert to the Proactive Information-Seeking stage to seek clarity or reaffirm existing beliefs.

While Definitive Surgical Decision and a well-prepared Preparation Phase represent the expected forward trajectory, some individuals fail to progress due to complex interactions among key cognitive variables, including elevated perceived threat, diminished self-efficacy, low response efficacy, and high response cost. These dynamics can disrupt the momentum of decision progression, leaving individuals in a state of prolonged hesitation or triggering repeated regressions back into the Proactive Information-Seeking and Decision-Making loops.

It is important to note that even among individuals who have formally opted for surgery or entered the preparation phase, the Decision-Making Process may continue up to the last moment before surgery. Participants often continue to grapple with internal negotiations among competing cognitive constructs, suggesting that definitive surgical intent may not always equate to final psychological resolution. This dynamic and recursive nature of decision-making represents a key theoretical contribution of this study.

Factors influencing the development direction of the stage

The key triggering factors throughout the decision-making process consistently included challenges posed by obesity, failed weight-loss attempts, and observational learning stimuli, with the challenges related to obesity being the most prominent. These challenges not only serve as the primary source of perceived threat at the cognitive level, but also act as critical drivers for initiating behavioral processes and constitute the starting point of the Cognitive Trade-off Theory for Bariatric Surgery (CTT-BS) proposed in this study. While these challenges fuel a strong desire for weight loss, repeated failures often leave individuals feeling trapped. Observing the successful weight-loss experiences of others frequently prompts contemplation of BS, a finding consistent with previous research [18, 19].

Weight-based stigma, infinite scroll reinforcement, and doctor’s initial recommendation emerged as important stimuli prompting individuals with obesity to begin exploring BS, with the first two being particularly influential. In the Chinese sociocultural context, weight-based stigma manifests in complex forms [20], including weight-related teasing, social gossip, hyper-vigilant scrutiny, weight-based attribution bias, and unfair treatment. Prior research suggests that such stigma may increase perceived threat and, in certain cases, positively influence self-efficacy by motivating action [21]. However, the long-term effects of this mechanism remain insufficiently validated and appear to depend heavily on individuals’ capacity to internalize negative information and emotions. Thus, healthcare professionals should be attentive to patients’ emotional responses and avoid reinforcing internalized weight bias.

Infinite scroll reinforcement is a particularly noteworthy factor. All participants reported being exposed to large volumes of BS-related content while using social media platforms. This phenomenon is closely linked to the current context in China, where personal data breaches are prevalent and the quality of online health information is highly variable [22, 23]. Studies have shown that the overall quality of BS information available online is relatively low [24, 25], particularly regarding the risks and management of surgical complications. Particular caution is warranted regarding the potential risks of infinite scroll reinforcement, including commercial content penetration (some even from unverified medical institutions), survivorship bias, and over-optimistic efficacy estimates. Our study found that over half of participants scheduled offline consultations through online platforms, while algorithm-driven content created ‘information cocoons’ that excessively exposed patients to singular perspectives. Although this phenomenon may prompt individuals to enter the decision-making stage, it could also lead to immature cognitive assessment, increasing cancellation risks and ultimately affecting surgical retention rates.The fundamental issue lies in healthcare providers’ dual-role failure: they neither regulate their own online promotional content nor effectively correct patients’ cognitive biases. When online information lacks source credentials (such as tertiary hospital certification), individuals with obesity struggle to distinguish professional advice from commercial promotion.We therefore recommend implementing tiered interventions: Healthcare institutions should strictly review their online content, prohibit misleading success cases, and proactively provide complication and long-term follow-up data. Preoperative care teams should incorporate ‘critical social media information evaluation’ training (such as identifying common exaggerated efficacy claims) and recommend verified information sources to patients. At the platform level, we advocate for credential transparency by mandating certification markers.

Another key finding of this study is the critical role of resource allocation, specifically the accessibility and trustworthiness of healthcare resources [26]. This is closely tied to the unique BS landscape in China, where numerous surgical institutions offer a wide range of choices for individuals with obesity. Consequently, resource allocation plays a pivotal role in stage progression. Even after undergoing a mature decision-making process, some individuals experience stagnation while awaiting access to a preferred surgeon or institution.The issue of credibility in medical resources may stem from the absence of stringent quality control or screening mechanisms, allowing patients to navigate a largely unregulated system of provider selection. This reflects a broader challenge that developing countries must collectively address. Although this study outlines the general image of the type of weight-loss surgeons patients tend to prefer, it does not explore their expectations regarding physicians’ personalities or communication styles. However, prior research indicates that trust and respectful physician–patient communication are essential facilitators in the decision to proceed with surgery [27, 28].Emerging digital technologies such as online consultations, robotic surgery, and telemedicine offer promising strategies to improve both the credibility and accessibility of medical services. In addition, promoting multidisciplinary BS teams may help enhance trust, ensure continuity of care, and support informed decision-making.

Complex environmental interactions

This study identified three key environmental factors—family support, peer support, and social pressure—and revealed their complex influence on the decision-making process for BS within the Chinese sociocultural context.

Family members are important sources of emotional and financial support [29]. However, the limited cognitive involvement of family support may be attributed to a culturally embedded “outcome-oriented” mindset in Chinese families, which tends to prioritize financial preparation (e.g., surgery cost coverage) over active participation in the decision-making process. This contrasts sharply with the Western model of continuous family engagement. Furthermore, our findings challenge the Western presupposition that family support is universally beneficial, and instead suggest that its influence is culturally scripted. Chinese families are more likely to shape perceived risk indirectly through “privacy-protective warnings” and “technical demystification” rather than by participating directly in cognitive deliberations. This insight offers a new target for culturally adaptive intervention strategies.

Our data also show that in certain cases, family support may amplify perceived threat. While most participants eventually received unconditional support from family members—typically mothers or partners—some chose not to disclose their surgical intent during the early stages of decision-making in order to avoid opposition or conflict. This behavior may stem from the strong emphasis on familial harmony in Chinese culture and the tradition of family-centered caregiving. When family members are involved in intimate care tasks, such as assisting with toileting or dressing, such experiences may provoke self-esteem activation in patients, heightening awareness of obesity-related health threats and thereby intensifying perceived threat.

We also recognize the significant role of peers and role models in the BS decision-making process [27, 30]. These individuals not only provide informational guidance but also offer emotional reinforcement to those seeking weight loss [31]. However, peer support can also generate negative effects—particularly by heightening perceived threat regarding surgical risks, weight regain, or complications arising from rapid weight loss. Therefore, when leveraging high-profile influencers or public figures to promote BS through trusted platforms such as public hospitals or health authorities, it is essential to balance their impact on perceived threat. Accurate, well-rounded information must be provided to help individuals respond to postoperative challenges appropriately and prevent the escalation of excessive perceived risk.

Although recommendations from healthcare professionals can facilitate access to BS-related information, we found that only a few participants had been influenced by referrals from physicians in other specialties, consistent with previous research [10, 27, 32]. In China, where there is no formal referral pathway for BS, the low referral rate is comparable. The general reluctance of healthcare providers to actively recommend BS merits further investigation.

In summary, environmental factors play a multifaceted and dynamic role in the BS decision-making process. Understanding the bidirectional mechanisms through which these factors operate is critical for developing more effective, culturally sensitive interventions that support individuals with obesity in making informed and confident decisions.

Cognitive trade-off theory for bariatric surgery

The CTT-BS was developed inductively through a constructivist grounded theory approach and is entirely rooted in the empirical data collected from in-depth interviews with individuals preparing to undergo BS. Rather than being imposed through pre-existing theoretical assumptions, the core constructs—such as self-efficacy, perceived threat, and response efficacy—emerged organically from participants’ narratives. Notably, while the model exhibits conceptual overlap with established behavioral theories, such as the HBM and PMT, these similarities reflect patterns present in the data rather than a deductive alignment with prior frameworks. The use of sensitizing concepts during axial coding was guided by theoretical sensitivity in the SCT [12], ensuring that external theories served only to aid interpretation, not to structure coding in advance.

The CTT-BS thus extends these existing models not by replicating their assumptions, but by demonstrating how such constructs interact recursively and dynamically in the high-stakes context of BS decision-making. This reflects a key epistemological distinction from traditional behavioral theories, which tend to assume linear causal relationships among predictors and outcomes.

For instance, in the HBM, perceived threat and perceived benefits are assumed to exert parallel effects on behavior, but are often modeled independently [33]. The CTT-BS challenges this separation by empirically demonstrating how perceived threat feeds into the formation of response efficacy, especially under conditions of escalating obesity-related health risks [34]. Likewise, while PMT identifies self-efficacy and response efficacy as parallel determinants of intention [14], the CTT-BS suggests that response efficacy can indirectly bolster self-efficacy by altering individuals’ interpretation of response cost—a pathway largely underexplored in previous models [35].

Moreover, the CTT-BS departs from linear “stimulus-response” assumptions and instead conceptualizes decision-making as a nonlinear, iterative process. This is particularly salient in the context of BS, which is a high-stakes, elective intervention involving significant cognitive, emotional, and logistical burdens [36]. Unlike decisions concerning routine health behaviors (e.g., vaccination, screening), BS entails a deliberative process punctuated by uncertainty, ambivalence, and reversibility [37]. The model accounts for such complexity by incorporating feedback loops (e.g., perceived threat reinforcing or undermining self-efficacy) and by positioning attitude not simply as a predisposing factor, but as a dynamically assembled outcome of cognitive negotiation.

In addition, the decision to undergo BS is deeply embedded in sociocultural scripts around body image, stigma, and medical trust. The CTT-BS captures this through its recognition of efficacy suppression, a phenomenon rarely acknowledged in existing behavioral theories. Here, high levels of perceived threat may paradoxically undermine perceived capability, especially in individuals who lack access to supportive networks or who have previously experienced failed weight-loss attempts—an insight that aligns with qualitative findings in obesity stigma literature [38, 39].

The model underscores the transactional nature of cognitive appraisal: individuals continuously weigh costs against benefits, not in absolute terms, but through a fluid negotiation mediated by efficacy beliefs. This positions CTT-BS as a theory particularly suited to explaining health decisions that unfold over time and are vulnerable to informational overload, emotional fluctuation, and contextual variability—core features of the BS journey.

Importantly, the interview data from this study also revealed potential cognitive biases in the decision-making process: While participants generally exhibited strong expectations regarding surgical benefits, most demonstrated markedly insufficient awareness of long-term challenges such as nutritional management and postoperative behavioral modifications. This “expectation-reality” discrepancy partially stems from the interaction between environmental factors (e.g., one-sided social media portrayals) and cognitive appraisal—when “infinite scroll reinforcement” disproportionately amplifies surgical benefits while downplaying risks, individuals’ “cost-benefit evaluation stalemate” may be resolved through non-rational mechanisms. These findings suggest the need for future research to explore how information credibility verification mechanisms could be integrated into decision-making theoretical frameworks, as well as how healthcare systems might implement structural interventions (e.g., standardized information provision) to mitigate environmentally induced cognitive biases without compromising patients’ decisional autonomy.

Limitations

We recognize potential selection and interpretation biases in our study, limiting the generalizability of our findings to all individuals with obesity, particularly due to geographic constraints. Despite our efforts to balance the demographic composition, our study cohort exhibited gender imbalance and an age distribution predominantly under 40 years old, which nevertheless aligns with the typical gender and age characteristics of bariatric surgery recipients in China [40]. As adolescent BS cases are rare in China, their perspectives were not included, potentially limiting the applicability of our decision-making mechanism to this demographic.The dynamic characteristics of surgical decision-making underscore the need for future longitudinal research to validate our findings.It is important to note that this study exclusively included participants who were scheduled to undergo surgery the following day. As a result, emotional bias may have been introduced, given that participants were situated at a heightened psychological state in the immediate preoperative period. Moreover, as individuals in the Abandonment stage were not represented in the sample, the findings’ tentative explanatory power for non-surgical populations requires rigorous empirical validation through targeted studies.

Conclusions

Employing Straussian Grounded Theory (SGT) analysis of pre-operative interviews with patients awaiting BS, this study systematically generated a substantive theory of decision-making comprising three interrelated dimensions: environmental contexts, cognitive processes, and temporal stages. The emergent model reveals that patients’ decisions evolve through six distinct yet interconnected phases, with axial coding demonstrating how conditional matrices (e.g., familial support structures) interact with cognitive phenomena (e.g., threat appraisal paradigms) to shape phase transitions. Crucially, the constant comparative method uncovered non-linear progression patterns where action/interaction strategies (e.g., information-seeking behaviors) are reconfigured in response to shifting contextual conditions. This dimensional interplay constitutes the core theoretical proposition of the study.

Supplementary Information

Supplementary Material 1. ^{(21.2KB, docx)}

Supplementary Material 2. ^{(18.3KB, docx)}

Supplementary Material 3. ^{(91KB, doc)}

Authors’ contributions

Yihong Xu and Wen Li contribute equally to the study as joint first authors. Yihong Xu: Conceptualization, Analysis, Methodology, Writing-original draft. Wen Li: Conceptualization, Formal analysis, Methodology, Writing-original draft. Liping Zhu: Analysis. Yunxia Li: Data curation, Formal analysis. Jianan Wang: Data analysis. Xiaoxiao Zhang: Formal analysis. Shanni Ding: Formal analysis. Mizhi Wu: Visualization. Hongying Pan: Writing– review & editing, Conceptualization, Resources, Supervision. Weihua Yu & Jionghuang Chen: Methodology, Resources.

Funding

This work was supported by a grant from the Zhejiang Provincial Medical and Health Science and Technology Programme (2020368373), the 2023 Zhejiang Provincial Medical and Health Science and Technology Programme (2023KY794), and the Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ24H160021).

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

This study received approval from the Ethics Committee of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Approval No. 20230316). All procedures were conducted in accordance with the ethical principles of the Declaration of Helsinki (2013 version).

Consent for publication

We informed each research participant about our intention to publish results from this study in scientific journals. All participants consented orally and in writing.

Competing interests

The authors declare no competing interests.