What Are the Basic Requirements for Bariatric Surgery

The prevalence of obesity continues to increase unabated. In 2014, approximately 52% of the adult population was overweight or obese (> 600 million) worldwide (1). Obesity represents a major health and economic burden. It also increases mortality and its associated complications, including cardiovascular disease, type 2 diabetes, and some cancers.

Long-term research studies demonstrated that the procedures involved in “Bariatric Surgery” results in significant long-term loss of weight, improvement in cardiovascular risk factors, recovery from diabetes, and a mortality reduction from 40% to 23% (2).

But what is it? What are the criteria you must meet to have this weight-loss surgery?

Find out this and more in this article!


What is Bariatric Surgery?

During the 1950s, the basic concept of bariatric surgery emerged, when procedures that involved small intestine resection were noted to result in weight loss.

In 1967, Mason and his colleagues performed the first gastric bypass procedure (3).

Bariatric surgery (or weight loss surgery) involves a variety of procedures that are performed on people who are obese. Long term weight loss achieved by the standard care of procedures that involve altering your gut hormone levels that are responsible for young hunger and satiety leads to a new hormonal weight set point.

Over the past decade, a noticeable increase in the number of bariatric surgery procedures carried out worldwide due to its effectiveness, with approximately 580,000 operations performed in 2014.

The two most commonly performed bariatric surgical procedures in the world are:

  • Roux-en-Y gastric bypass
  • Sleeve gastrectomy

Figure:  Two most commonly performed bariatric surgical procedures in the world with relative percentages (RYGB Roux-en-Y gastric bypass, SG Sleeve gastrectomy).

Bariatric Surgery

Guidelines to Qualify For Bariatric Surgery

In 2013, National Institute of Health symposium summarized available beneficial evidence of bariatric surgery as;

  • 29% mortality reduction
  • Fewer cardiovascular events
  • A 10-year remission rate of type 2 diabetes of 36%
  • A lesser rate of diabetes-related problems in a long-term, non-randomized, matched intervention 20-year follow-up study, the Swedish Obese Subjects Study (4)

Here is what you need to know;

  1. What are the indications for bariatric surgery?
  2. What are the contraindications specific for bariatric surgery?
  3. Why you need Pre-Operative Evaluation?
  4. Why you need Psychological Support?
  5. Why you need Follow-Up?


Indications for Bariatric Surgery

For qualifying for bariatric surgery, you may need to meet certain medical guidelines. If you qualify, you likely will have an extensive screening process to see. Below are some indications for different age groups;

Indications for Bariatric Surgery about BMI

(Age from 18 to 60 years)


(Age above 60 Years)

·         With BMI ≥ 40

·         With BMI 35–40 with comorbidities

·         BMI threshold by 2.5 (individuals of Asian genetic background)

·         BMI > 40 (or 99.5th percentile for respective age)

·         At least one comorbidity


·         Not Known






Bariatric Surgery in age groups from 18 to 60 years

In general, for patients of 18 to 60 years, weight-loss surgery could be an option if:

  1. With BMI ≥ 40
  2. With BMI 35–40 with comorbidities in which bariatric surgery is expected to improve the disorder (such as metabolic disorders, cardio-respiratory disease, severe joint disease, obesity-related severe psychological problems).
  3. BMI criterion may be the current BMI, or previously maximum attained BMI of this severity. Also note that:
  4. Bariatric surgery is indicated if you exhibited a considerable weight loss in a conventional treatment program but again started to gain weight, even if the required minimum indication weight for surgery has not yet been attained again.
  5. To be considered for bariatric surgery, you should have failed to lose weight or to maintain long-term weight loss, despite appropriate surgical or non-surgical comprehensive medical care (5).
  6. If you are an individual of Asian genetic background, consideration should be given to preserve the balance between genetic and environmental/dietary factors and to reduce the BMI threshold by 2.5.
  7. You should have also shown your compliance with scheduled medical appointments.

Bariatric Surgery in Children/Adolescents

In adolescents and children, indication for bariatric surgery could be considered in centers with extensive experience of such treatment in adults. Moreover, those centers must be able to offer a truly multidisciplinary approach, which involves pediatric skills relating to surgery, dietetics, and psychological management.

In adolescents with severe obesity, bariatric surgery can be considered(6):

  1. The patient has a BMI >40 (or 99.5th percentile for respective age) and at least one comorbidity.
  2. The patient is capable of committing to comprehensive medical and psychological evaluation before and after surgery.
  3. The patient has followed at least six months of organized weight-reducing attempts in a specialized center.
  4. The patient shows skeletal and developmental maturity
  5. The patient is ready to take part in a postoperative multidisciplinary treatment program.
  6. The patient can access surgery in a unit with specialist pediatric support (nursing, anesthesia, psychology, postoperative care).

In genetic syndromes such as Prader-Willi syndrome, bariatric surgery can be considered only after careful consideration of an expert medical, pediatric, and surgical team.

Bariatric Surgery in Those Aged above 60

Before surgery is contemplated in elder individuals, the proof of a favorable risk-benefit must be demonstrated in elderly or ill patients.

In elderly patients, the primary objective of surgery is to improve the quality of life, even though surgery is unlikely to increase lifespan (7).

Contraindications Specific for Bariatric Surgery

  1. Absence of a period of identifiable medical management
  2. Unable to participate in prolonged medical follow-up
  3. Personality and eating disorders, non-stabilized psychotic disorders, severe depression, unless exclusively advised by a psychiatrist qualified in obesity
  4. Alcohol abuse or drug dependencies
  5. Diseases threatening life in the short term
  6. Patients who are not capable of caring for themselves and having no enduring family or social support that will guarantee such care

Patient Pre-Operative Evaluation

A decision to offer a bariatric surgery should follow a comprehensive interdisciplinary assessment. The core team providing such assessment should optimally consist of the following specialists experienced in obesity management and bariatric surgery (8);

  • Physician
  • Surgeon
  • Anesthetist
  • Psychologist or psychiatrist
  • Nutritionist or dietitian
  • Nurse practitioner / social worker

If you are indicated for bariatric surgery, you should undergo routine pre-operative assessment as for any other major abdominal surgery. Pre-operative management should include assessment of your general health and nutritional status as follows;

  • Explanation of your dietary changes that are required after surgery
  • Optimizing treatment of comorbidities to reduce the risks of the surgical procedure
  • Assessment of your motivation and willingness to adhere to follow-up programs
  • Ensuring that you are fully informed on the benefits, consequences, and risks of the surgical options and the necessity of lifelong follow-up
  • Ensuring that you understand the potential (limited) outcomes of surgery
  • Ensuring that you can give truly informed consent, including a statement on risks of the surgery and acceptance of lifestyle modification, including behavioral changes and follow-up compliance.

In addition to the routine pre-operative assessment as for any other major abdominal surgery, you should undergo further assessment for (depending on the planned bariatric procedure and clinical status of the patient) (9);

  • Sleep apnea syndrome and pulmonary function
  • Metabolic and endocrine disorders
  • Gastro-esophageal disorders
  • Bone density
  • Body composition,
  • Resting energy expenditure


Psychological Support

Pre-Operative Psychological Support

Psychological assessment of behavioral, nutritional, familial, and personality factors is an integral part of your pre-operative evaluation (10).

For weight loss surgery, the purpose of the psychosocial evaluation is not merely diagnostic, but to create an individually tailored treatment plan by enhancing the safety and efficacy of surgical treatment and identifying areas of potential vulnerability, challenges, and strengths.

The Pre-operative psychological evaluation should always include assessment of psychopathology such as

  • Personality examination
  • Assessment of your expectation/motivation
  • Diet history
  • Lifestyle (i.e., nutritional behavior, physical activity habits, life conditions)
  • Social support network
  • Post Psychological disorder (depression, anxiety, etc.)

Pre-operative evaluation helps to identify the interventions that can increase long-term compliance and weight maintenance (i.e., psychological support, psychotherapy, crisis intervention)  (11).

The goal is to enhance your motivation and ability to comply with nutritional, behavioral, and psychosocial changes before and after bariatric surgery.

Postoperative Psychological Support

Eating pathologies, such as binge eating disorder (BED), increase the risk of and lower weight loss and weight regain after some bariatric procedures (12).

Moreover, the existence of two and more psychiatric/mental disorders enhances the threat of insufficient weight loss after both pure food restrictive as well as metabolic types of procedures.

Pre-operative identification of psychological risk factors associated with lower postoperative compliance, inadequate weight loss, alcohol or drug dependencies, eating pathologies, and others should lead to postoperative interventions through implementing a self-monitoring strategy in higher-risk patients.


Our Final Words

Morbid obesity is a lifelong disease. Your treating physician and surgeon are responsible for the treatment of your comorbidities before the operation and for the follow-up after the operation.

The information listed above is derived from credible scientific resources. Please note that it is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We strongly encourage you to discuss any questions or concerns you may have with your healthcare provider.

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