Definition and classification of obesity:
The World Health Organization (WHO) defines obesity as a state of excessive fat accumulation in the body to the extent that it negatively affects health and well-being.1 If the amount of body fat exceeds normal physiological values, a person is obese. Physiologically, the normal amount of body fat varies widely between individuals depending on age and gender.
BMI (Body Mass Index, BMI), which is determined by dividing weight by height in meters, is most commonly used to classify the degree of obesity.2,3 In general, the healthy BMI range is 18.5 to 24.9 kg/m2. Overweight is defined as a BMI of 25 to 29.9 kg/m2. When the calculated BMI exceeds 30 kg/m2, it is defined as obesity. Obesity can be subdivided according to subclasses of BMI. Accordingly, BMI: 30-34.9 Class 1 obesity; BMI:35-39.9 Class 2 obesity; BMI: 40 and above is called Class 3-extreme obesity. If BMI is 50 and above, the term superobesity is used. Diseases associated with obesity generally occur when BMI increases to 30 and above. For this reason, when obesity occurs along with diseases such as diabetes, hypertension, coronary artery disease, sleep apnea, joint deformities, depression, and obesity-related reflux disease, we use the term morbid obesity.
Another important parameter is waist circumference, which can be used together with a BMI value to assess the health risk of individuals. Waist/hip ratio is related to the distribution of body fat. Patients with a waist/hip ratio of less than 1 tend to have a peripheral fat distribution ratio, often referred to as a “pear” distribution. This fat distribution has a low health risk. Patients with a waist/hip ratio of more than 1 are called “apple” or central fat distribution, and these patients are considered to have a high health risk.
In children (ages 2-19), overweight is defined as obesity if the BMI for age is equal to or greater than the 95th percentile on the Centers for Disease Control and Prevention (CDC) growth charts, and overweight if it is between 85-9.4
33.0% of the world’s adult population (1.4 billion people) is overweight or obese, a significant and increasing public health problem in both economically developed and developing regions of the world. More than 1.4 billion adults were overweight in 2008 and more than 40 million children under five in 2010. If recent trends continue, it is estimated that the overweight or obese rate of the world’s adult population will increase to 57.8% of the total population (3.3 billion people) by 2030.5
There is a clear need for increased public awareness and education about the complex etiology of obesity and the significant barriers that exist in efforts to achieve sustainable weight loss. Obesity is a chronic disease with a complex etiology and a lifelong condition for most obese people. Therefore, the wound caused by being labeled obese from a young age lasts a lifetime. Supporting individuals, regardless of the patient’s age, with adaptive psychological ways to cope with weight stigma may facilitate weight loss outcomes.
After this introduction, it is necessary to draw attention to one point. The death rate from obesity-related conditions increases with age; Significantly higher all-cause mortality has been noted in obese individuals compared to normal weight subjects, and one study noted that mortality was likely to occur 9.44 years earlier in those who were obese (BMI, ≥30).6 The deleterious effects of obesity on the cardiovascular system and health conditions such as cancer Due to its problems, the effects of bariatric surgery on overall survival have been proven in many studies. For example, in the Swedish SOS study, it was reported that there was a 30.7% improvement in mortality in 10 years.7 Again, in a meta-analysis published by Cardoso et al. in 2017, it was reported that the population who had undergone bariatric surgery reduced mortality by 41% compared to the obese population who had not undergone surgery.8 Therefore, it caused serious health problems and increased mortality. Treatment of obesity, which accelerates obesity, is essential
Why do we become obese? How do we develop a feeling of hunger and a feeling of satiety?
There are both neural and hormonal communication pathways between the brain and the digestive system.
When we are hungry, the Ghrelin hormone released from an empty stomach sends a signal to the brain – you are hungry, eat – while the Leptin hormone released from a full stomach when we are full sends a signal – you are full, stop eating now. This continues in a state of balance.
The region in our brain called the hypothalamus provides the balance between the intake of nutrients and the consumption of the resulting energy. Under the management of this center, the need for energy, water and other nutrients, and the feeling of hunger, satiety and thirst emerge. The nutrients taken into the body, from highest to lowest according to their calorie content, are fats, carbohydrates, proteins, vitamins and minerals. Once these substances are ingested, they are metabolized and thus life continues. Food intake of an adult individual roscopic Adjustable Gastric Banding (LAGB) became popular in a short time due to the ease of the technique and the absence of any anatomical changes when it was first used. These silicone bands are placed in the stomach through a tunnel created in the esophagogastric junction16. A port similar to chemotherapy ports is placed under the skin to be adjustable. From here, a special needle is inserted and the lumen diameter is adjusted with physiological saline. For example, if he has lost a lot of weight, it is extinguished. If weight loss is insufficient, it is inflated. However, over time, many complications such as slippage of these balloons, migration into the stomach by piercing the stomach wall, and port site infections have emerged, and today they are rarely used in very selected cases17 (Figure 2)
Figure 2: Laparoscopic Adjustable Gastric Band (LAGB) and non-adjustable MiniMizer Gastric band types.
b) Sleeve gastrectomy (sleeve gastrectomy): Sleeve gastrectomy is the technique of laparoscopic surgical removal of approximately 75-80% of the stomach in the vertical plane (Figure 3). This surgery was actually the first phase of the biliopancreatic diversion technique, which is a more complex surgery. However, while waiting for second-stage surgery, patients experienced improvement in serious comorbidities and adequate weight loss. Thereupon, it began to be performed as a stand-alone obesity surgery technique in the first half of the 2000s. The normal anatomical sequence does not change in sleeve gastrectomy. There is no serious deterioration in the absorption of foods, vitamins and trace elements. For this reason, it has become the most frequently applied surgical technique today18-25
Figure 3: Laparoscopic sleeve gastrectomy. This surgery is performed laparoscopically with special equipment called endostapler. (shutterstock stock number:1135976798)
- Absorption-limiting, malabsorptive techniques:
a) Jejuno colic bypass (abandoned),
b) End-to-side jejuno ileal bypass
- Volume restrictive + absorption restrictive (restrictive + malabsorptive) techniques:
a)Roux-en-Y gastric bypass: It is both a volume restricting and malabsorption technique for weight loss. It has been used for the treatment of obesity since the 1970s26. In this surgery, a small gastric pouch is created in the proximal part of the stomach. Then, the small intestines are connected to the stomach in a Y shape (Figure 4). Since it is a volume-restricting and malabsorption technique, it is preferred to sleeve gastrectomy in morbidly obese individuals with type 2 diabetes.27 Since it impairs absorption, lifelong nutritional status, protein and vitamin levels, and trace elements should be checked and replaced when necessary.
b)Mini gastric bypass=MGB=(single anastomosis gastric bypass=SAGB, one anastomosis gastric bypass=OAGB) Minigastric bypass was developed as an alternative to Roux-en-Y gastric bypass surgery28. In this surgical technique, a proximal gastric pouch is created. The small intestine is then connected to this pouch with a single anastomosis (Figure 5). Since it disrupts absorption, its follow-up is the same as Roux-en-Y bypass.
c)Transit bipartition: (Roux-en-Y type = TB or loop TB (single anastomosis sleeve ileostomy = SASI). Transit bipartition surgeries were developed to correct type 2 diabetes, which occurs as a side effect of obesity in people who are obese (BMI between 33-72). It is a surgery.29 Sleeve gastrectomy is performed as a volume restrictor, and it is reported that the tube stomach and small intestine are opened as an malabsorptor, causing the release of incretins from the ileum, which are effective in overcoming insulin resistance.29 It is also an effective method in the treatment of type 2 diabetes. Ileal interposition-transposition surgeries are performed on overweight people.30
In recent years, studies on single anastomosis sleeve jejunostomy (SAS-J)31 as volume restricting + malabsorption have been ongoing.
