Impacts of Bariatric Surgery on Metabolic Health and Quality of Life: A Systematic Review

Introduction: Bariatric surgery has established itself as an effective treatment for severe obesity, benefiting the metabolic health and quality of life of patients who do not respond to conventional weight loss approaches. With obesity being a risk condition associated with diseases such as type 2 diabetes, hypertension and cardiovascular problems, the search for surgical solutions has grown, also representing a response to a global public health problem. 

Objective: To analyze the impacts of bariatric surgery on the metabolic health and quality of life of patients, evaluating the physiological, hormonal and emotional changes resulting from the procedure. 

Methods: This study constitutes a systematic review, classified as exploratory and descriptive. The preparation of the research was a bibliographical search in electronic databases on methods associated with SLR (Systematic Literature Review) and the applications of SMARTER (Simple Multi-Attribute Rating Technique using Exploiting Rankings). Results: A comprehensive systematic search of the literature yielded a total of 1963 articles referring to the impact of bariatric surgery on metabolic health and quality of life, of which 38 articles were eligible to be included in this systematic review. 

Conclusion: Bariatric surgery represents an effective intervention in promoting significant improvements in the metabolic health and quality of life of patients with severe obesity. However, although the results are promising, the need for ongoing monitoring and interdisciplinary support to optimize and maintain long-term benefits is highlighted.

Bariatric surgery has established itself as an effective treatment for severe obesity, benefiting the metabolic health and quality of life of patients who do not respond to conventional weight loss approaches (ADERINTO et al., 2023; KOSCHKER et al., 2023; RIBEIRO et al., 2024). With obesity being a risk condition associated with diseases such as type 2 diabetes, hypertension and cardiovascular problems, the demand for surgical solutions has grown, also configuring itself as a response to a global public health problem (DONA et al., 2022; MOHAJAN; MOHAJAN, 2023). More than just promoting weight loss, bariatric surgery induces important hormonal and metabolic adaptations, with effects such as improved insulin production, decreased insulin resistance and, in some cases, remission of type 2 diabetes (JI et al., 2021; YIN et al., 2023). The impact of surgery extends to the mental and social health of individuals, since significant weight loss contributes to self-esteem, reduces symptoms of anxiety and depression, and facilitates social reintegration (RIGAL et al., 2021; VAN ZYL; LUSHER; MEYRICK, 2024). In addition to the physical transformation, patients who under go the procedure may experience improvements in their quality of life, such as greater willingness to perform physical activities and more autonomy in daily tasks (AHLICH et al., 2021; RIBEIRO et al., 2024). This recovery process is supported by the interaction between physical and emotional gains, making bariatric surgery a rehabilitation and social inclusion intervention (ROBINSON et al., 2022).

However, surgery is not without risks and requires continuous monitoring, which must involve a multidisciplinary team that includes nutritionists, psychologists, endocrinologists, and surgeons. This monitoring helps prevent complications, such as nutritional deficiencies and other postoperative problems, which are essential for maintaining the results. To ensure a successful process, the patient must be committed to monitoring and adjusting their new lifestyle (ALOBAIDLY; HASAN, 2024; COELHO et al., 2021). In terms of public policy, bariatric surgery represents an intervention with the potential to reduce healthcare costs related to the treatment of chronic conditions linked to obesity. In many countries, surgery is partially subsidized for patients who meet specific clinical criteria, which is an investment in public health. This coverage by the public health system, therefore, expands access to treatment, providing individual benefits that are reflected in society by reducing the financial impact of diseases associated with obesity (TURRI, 2022). Recent studies and research confirm the durability of the metabolic and mental health benefits of bariatric surgery in the long term, showing a reduction in mortality among patients with morbid obesity. Even with these advances, there is still a need for additional research to understand the effects of surgery on the metabolic and emotional adaptations of patients over the years, which may help in future improvements in treatment and monitoring protocols (ABDUL WAHAB; LE ROUX, 2022; BUDNY et al., 2024; LAW et al., 2023; TAN et al., 2022).

Bariatric surgery is therefore a powerful intervention in the management of obesity, bringing broad benefits to both the patient and the healthcare system. As a life-transforming tool, this surgery offers a comprehensive approach to overall well-being, ranging from alleviating physical and metabolic conditions to strengthening mental and social health. These results underscore the importance of bariatric surgery not only as a means of weight loss, but as a procedure that promotes a comprehensive and integrated recovery of the quality of life of individuals. This systematic review aims to analyze the impacts of bariatric surgery on patients' metabolic health and quality of life, evaluating the physiological, hormonal, and emotional changes resulting from the procedure. The study sought to understand the implications of bariatric surgery as a public health intervention, observing its potential to reduce the financial impact of obesity-related diseases on the health system. By gathering these data, we seek to provide an understanding to offer recommendations for clinical practice and future research.

This study is a systematic review, classified as exploratory and descriptive. The research was carried out through bibliographic research in electronic databases on methods associated with SLR (Systematic Literature Review) and applications of SMARTER (Simple Multi-Attribute Rating Technique using Exploiting Rankings). The work carried out is of a qualitative and quantitative nature. The qualitative analysis of the data was carried out intuitively and inductively during the survey of the theoretical framework. It is also quantitative by using the multicriteria method. In addition, there is also a numerical experimental study in order to simulate a situation of article selection based on the observed criteria. The bibliographic research was carried out in the following databases: Web of Science; Science Direct; Wiley; Springer Link; Taylor and Francis and PubMed. In addition, searches were carried out using bibliographic references of studies that addressed the topic in a relevant manner on the Google Scholar search platform.

The search in the databases was carried out using the terminologies registered in the Health Sciences Descriptors created by the Virtual Health Library developed from the Medical Subject Headings from the US National Library of Medicine, which allows the use of common terminology in Portuguese, English and Spanish. The present study sought to investigate the literature on the impacts of bariatric surgery on metabolic health and quality of life of patients. For this purpose, the descriptors “bariatric surgery”, “metabolic health” and “quality of life” were used, initially in English, and complementary in Spanish and Portuguese. As a tool to support decision-making in the selection and prioritization of articles, a set of criteria were considered essential to represent the state of the art of the research topic. This method has the following characteristics: (i) rigorous logic allows the method to be accepted as a decision-making support tool; (ii) simple to understand and apply with results that are easy to interpret.

References of selected papers were also searched for other documents of potential interest. Once qualified for full text in the evaluation, articles were included in the qualitative review if they met the following inclusion criteria: a) contained data on bariatric surgery; b) contained data on the impact of bariatric surgery on metabolic health; c) contained data on the impact of bariatric surgery on quality of life. Articles were excluded if they were reports, banners or conference abstracts. There was no review of confidential health information and the study was not interventional. Therefore, ethics committee approval was not necessary. In the end, the result obtained totaled 38 articles that contemplated the desired characteristics for the study. Four independent researchers extracted data from articles that met the inclusion criteria and recorded them in a “data extraction form” generated in Microsoft Excel on the impact of bariatric surgery on metabolic health and quality of life. From this form, the authors and year of publication, study title, study type, results and conclusion were included, which is shown in Table 1.

A comprehensive systematic literature search yielded a total of 1963 articles regarding the impact of bariatric surgery on metabolic health and quality of life. Of these, 252 studies were excluded due to data overlap. From this, the SMARTER (Simple Multi-Attribute Rating Technique using Exploiting Rankings) method was chosen and 173 articles that were suitable for full-text screening were selected, of which 135 articles were included for data extraction, of which 97 were excluded by the exclusion criteria, making 38 articles eligible for inclusion in the systematic review. In Figure 1, we describe the selection strategy of articles on the topic in question.

Figure 1: Article search strategy

Source: Authors (2024)

Table 1: Some selected studies and their main findings

Source: Authors (2024)

Source: Authors (2024)

Source: Authors (2024)

Bariatric surgery has been consolidated as an effective intervention in the treatment of severe obesity and its comorbidities, bringing significant benefits to patients' metabolic health and quality of life (BUDNY et al., 2024; RIBEIRO et al., 2024). Several studies indicate that this intervention leads to consistent weight loss, in addition to promoting the improvement or even remission of metabolic conditions, such as type 2 diabetes and hypertension, also beneficially influencing psychological and social aspects (ARISHI et al., 2023; DAVIES et al., 2022; DILEKTASLI; DEMIR, 2021; KESHAVJEE et al., 2021; ROTHBERG; LEAN; LAFERRÈRE, 2024). Regarding metabolic health, it is observed that weight loss resulting from bariatric surgery leads to significant changes in glucose metabolism and insulin sensitivity (JABBOUR; SALMAN, 2021; JI et al., 2021). Studies indicate that remission of type 2 diabetes occurs in a significant percentage of patients undergoing surgery, especially those with shorter disease duration and greater functional reserve of pancreatic beta cells (RICCI et al., 2023). Surgery positively affects patients' lipid and inflammatory profiles. The reduction in blood pressure, together with the improvement in the lipid profile (decrease in LDL cholesterol and triglyceride levels, combined with the increase in HDL cholesterol), helps to reduce long-term cardiovascular risk (DOUMOURAS et al., 2021; TANG et al., 2022). Likewise, reducing chronic systemic inflammation, which is common in obese individuals, improves endothelial function and reduces the propensity to develop vascular complications (KAJIKAWA; HIGASHI, 2022). Thus, the metabolic benefits of bariatric surgery go beyond weight loss, providing greater protection against adverse cardiovascular events.

Another crucial aspect is the improvement in the quality of life of individuals who have undergone surgery. Excess weight often limits mobility, makes it difficult to engage in physical activities, and generates negative psychological impacts, such as low self-esteem, depression, and anxiety (GOEL; REDDY; GOEL, 2024; WU, 2022). With significant weight loss, there is an improvement in physical functionality, allowing greater independence in daily activities and encouraging the adoption of healthy habits, such as regular exercise (SCHMID et al., 2023). The relationship between obesity and mental health is also worth highlighting. Studies indicate that obese individuals have a higher incidence of psychological disorders, including depression and anxiety disorders (DAKANALIS et al., 2023; RINDLER; GRIES; FREIDL, 2023). Bariatric surgery, by reducing body weight and improving the perception of self-image, contributes to improving emotional well-being (ABOKHOZIMA et al., 2025). However, it is important to emphasize that some patients may develop or worsen eating disorders postoperatively, which reinforces the need for continuous psychological support (VAN ZYL; LUSHER; MEYRICK, 2024).

Despite the numerous benefits, bariatric surgery is not without its risks and challenges. Nutritional deficiencies are a recurring concern, especially in procedures involving intestinal diversion, such as gastric bypass. Poor absorption of vitamins and minerals can lead to complications such as anemia, osteoporosis, and neurological disorders, making nutritional monitoring and adequate supplementation essential (MOIZE; LAFERRÈRE; SHAPSES, 2024).

In addition to nutritional complications, weight regain over the years is a factor that must be considered. Some patients, even after a period of significant weight loss, may regain part of the weight lost, which may be related to factors such as changes in eating habits, lack of physical activity, and psychological issues (NORIA et al., 2023). Long-term success depends on the patient's adherence to a new lifestyle and maintenance of multidisciplinary monitoring, such as doctors, nutritionists, psychologists, and physical educators, to ensure the maintenance of the benefits obtained with the procedure and minimize risks and complications. (M. JORGE; M. TIESENGA, 2023; TAN et al., 2022).

In addition to individual impacts, bariatric surgery can also have positive effects on public health. Obesity is a condition that generates high costs for health systems, due to the treatment of its associated complications (MOHAJAN; MOHAJAN, 2023). By promoting the reduction of obesity and its comorbidities, bariatric surgery can reduce the demand for hospital care, hospitalizations and use of medications, representing an economically viable strategy in the long term. (TURRI et al., 2022). Thus, bariatric surgery has established itself as an effective strategy for treating obesity and its comorbidities, promoting metabolic benefits and significant improvements in quality of life. However, the approach must be individualized, ensuring that each patient receives the necessary support to obtain positive and lasting results. Future studies may contribute to the improvement of surgical techniques and to understanding the factors that influence the maintenance of long-term benefits.

Bariatric surgery is an effective intervention for promoting significant improvements in metabolic health and quality of life in patients with severe obesity. A consistent reduction in related comorbidities, such as type 2 diabetes, hypertension and dyslipidemias, as well as substantial improvements in glycemic control and lipid profiles, has been observed. The benefits also extend to psychological well-being, with evidence of a reduction in symptoms of anxiety and depression, as well as greater satisfaction with body image and quality of life. However, although the results are promising, there is a need for continued monitoring and interdisciplinary support to optimize and maintain long-term benefits. Limitations, such as the risk of nutritional deficiencies and surgical complications, reinforce the importance of regular postoperative care. Future studies should explore preventive interventions for these risks, in addition to evaluating patient experience over time, providing a more complete understanding of the sustained effects of bariatric surgery.