Bariatric Surgery

The approach is individualized. If you feel you need help managing obesity or a metabolic disorder, a personal assessment and discussion are recommended. In most cases, according to international guidelines, surgery is indicated for patients with a BMI over 35, or over 30 if associated health conditions are present.

Medical (non-surgical) treatment for severe (morbid) obesity typically involves various combinations of low-calorie diets, behavioral modifications, physical exercise, and medication. However, a major limitation of these methods is the difficulty of maintaining reduced body weight over the long term. It is common for patients to be unable to sustain even a 10% loss of their initial weight using these approaches.

Due to the significant risks associated with severe obesity, the relatively low risks of surgical treatment, and the limited effectiveness of medical or dietary interventions, bariatric surgery has become a well-established and effective solution. It not only enables significant and sustained weight loss but also improves related health conditions. Additionally, it prevents the weight fluctuations (yo-yo effect) often associated with conservative treatments, which can worsen metabolic health.

In summary, bariatric surgery helps control weight by altering the body’s energy balance in one or both of the following ways:

• Reducing the amount of food consumed (restriction);
• Decreasing nutrient absorption, causing some of the food not to be fully digested and instead eliminated through feces (malabsorption).

To better understand how surgery contributes to weight loss, it is essential to know how the digestive system works.

After chewing, food travels through the esophagus, a long muscular tube that transports it to the stomach. The stomach, which can hold more than 1500 mL of food, mixes it with hydrochloric acid and breaks it down into a substance called chyme. This chyme then moves into the small intestine (duodenum), where it mixes with bile and pancreatic juices, continuing the digestion process. The small intestine, measuring between 4.5 and 6 meters, is primarily responsible for nutrient absorption.

In the duodenum, food mixes with bile and pancreatic juices, making this region the main site for absorbing iron, calcium, magnesium, and other divalent ions. The ileum, the distal portion of the small intestine, plays a crucial role in absorbing nutrients, including fat-soluble vitamins (A, D, E, and K). As food reaches the colon, its consistency becomes more solid due to water absorption.

The fundamental principle of obesity surgery is to alter the balance between intake, absorption, and energy expenditure, which in obesity favors weight accumulation. Thus, reduced food intake, decreased nutrient absorption, and regular physical exercise collectively contribute to weight loss.

Beyond these mechanisms, an important endocrine factor comes into play: the accelerated arrival of semi-digested food to the distal part of the small intestine. This stimulation activates a set of gastrointestinal hormones essential to the mechanism of metabolic surgery, such as GLP-1, GLP-2, GIP, PYY, and FGF19, among others. The incretin effect of these substances plays a crucial role in glycemic control and, consequently, in the long-term regulation of the patient’s weight.

Weight loss after surgery is not the same for all patients and varies according to several factors, such as age, initial weight, ability to exercise, consumption of sweets, type of surgery performed, among others. On average, a surgery is considered successful when there is a loss of 20% of the initial weight (% Total Weight Loss). However, the results are highly individualized. During a consultation, it will be possible to predict expected weight loss in the medium and long term, as well as control of associated health conditions.

Although the age range between 18 and 60 years has no restrictions for surgery, studies indicate that patients younger than 18 or older than 60 can be considered candidates for the procedure after careful evaluation. Therefore, age alone is not an exclusionary factor for performing bariatric surgery.

Surgery always requires a few days off work. Depending on an individual’s professional schedule, additional time might be needed to allow proper adaptation to the dietary plan, which requires frequent small meals every two hours during the initial weeks.

In addition to schedule adjustments, it is essential to consider the physical demands of one’s job. For one month after surgery, lifting heavy weights or performing gym exercises that target abdominal muscles is discouraged to prevent the development of incisional hernias.

Loose skin after surgery does not always occur. Adherence to an appropriate nutritional plan, proper hydration, and regular physical exercise can reduce or even eliminate the need for reconstructive surgeries. However, in the long term, after weight stabilization (approximately one year post-bariatric surgery), some patients may be candidates for surgical or aesthetic procedures. Such decisions should be thoroughly evaluated and discussed during consultations with specialists.

Nutritional guidelines should be provided by a professional experienced in bariatric and metabolic surgery, starting from the preoperative period. This preparation is essential to minimize surgical risks and optimize long-term results. Post-surgery, regardless of the surgery type, patients are generally instructed to follow a liquid diet with protein and vitamin supplementation (prescribed) for two to three weeks.

Obesity is a chronic, multifactorial, and recurring disease. Like any other treatment, surgery can also have cases of failure. Initially, there is a small percentage of patients who do not lose the expected weight after surgery (non-responders), and in the long term, another group may regain weight. This weight regain occurs in approximately 15-20% of cases, regardless of the type of surgery performed. However, given the chronic nature of obesity, it is essential to understand that in cases of weight stabilization or regain, other strategies—such as a more tailored exercise plan, medication, nutritional adjustments, or even conversion to another surgical procedure—may be necessary to achieve desired results, either in weight loss or in controlling associated conditions.

The success of bariatric surgery depends on several factors, some modifiable and others not, as well as the active participation of everyone involved in the process. This includes choosing the right medical team to guide the treatment, defining an individualized plan, selecting the surgical procedure, and ensuring continuous follow-up care.

However, when it comes to individual patient factors, success largely depends on the ability to adapt and adhere to the behavioral changes recommended to optimize results. Understanding each step of the process, from the preoperative evaluation to concerns addressed during follow-up consultations, is essential. Building a relationship of trust, closeness, and open communication between the patient and the medical team is fundamental to achieving the best outcomes.

Together with the surgeon, it will be necessary to evaluate the risks and benefits of each procedure. Additionally, a protocol of pre-surgical tests and multidisciplinary assessments is essential in determining the most appropriate procedure for the disease and the patient’s psychological profile.

We also highly recommend that patients connect with others who have undergone bariatric surgery to hear about their experiences. This can help you make a more informed and conscious decision about your treatment.

It is important to remember that surgery alone does not cure obesity. Only patients who are well-informed and willing to change their lifestyle by committing to a long-term follow-up program will have the greatest chances of success with the proposed treatments. Keep in mind that obesity is a chronic disease, which cannot be cured but can be controlled, whether through surgery or other medical interventions.