Obesity is a health condition whose prevalence is steadily increasing worldwide. If left untreated, it can lead to numerous acute and chronic diseases such as heart disease, diabetes mellitus, and hypertension, making it a serious medical issue that requires careful management.

Among the diseases for which obesity is a major risk factor are type 2 diabetes mellitus, hypertension, cardiovascular diseases, as well as breast, prostate, and colorectal cancers, and various gynecological conditions.

The primary causes of obesity include unhealthy dietary habits and a sedentary lifestyle. However, the exact underlying mechanisms are not fully understood. It is known that genetic predisposition, physiological factors, as well as cultural and environmental influences play significant roles. Fundamentally, obesity results from an energy imbalance—when daily caloric intake exceeds energy expenditure, leading to fat accumulation in the body.

Obese individuals often experience reduced physical activity due to increased body weight. This reduction further decreases calorie expenditure, accelerating the progression of obesity. Unless this vicious cycle is broken, obesity can have destructive effects on quality of life and all bodily systems.

Considering the aesthetic concerns caused by excess weight, life-threatening diseases associated with obesity, chronic conditions requiring lifelong treatment, and the psychological burden of severe health problems, obesity must be treated with a multidisciplinary approach.

At İstanbul Regional Hospital (Sancaktepe), our Obesity and Metabolic Surgery Department works collaboratively with all other departments. The first step in treatment is diagnosing obesity and determining its severity.

Diagnosis of Obesity

Obesity is determined using the Body Mass Index (BMI), calculated as:

BMI = Body weight (kg) / height² (m²)

The results are interpreted as follows:

• BMI < 18.5 → Underweight
• BMI 18.5–24.9 → Normal weight
• BMI 25.0–29.9 → Overweight
• BMI 30.0–34.9 → Class I obesity
• BMI 35–39.9 → Class II obesity
• BMI > 40 → Morbid obesity
• BMI > 50 → Super obesity

After diagnosis, the next crucial step is determining whether obesity-related comorbidities are present. Patients are evaluated in collaboration with neurology, cardiology, cardiovascular surgery, and endocrinology departments when necessary.

Diseases Caused by Obesity

Insulin Resistance and Diabetes Mellitus

Excess fat accumulation reduces the body's sensitivity to insulin, leading to insulin resistance. This condition precedes prediabetes and eventually type 2 diabetes mellitus.

Hypertension

Hypertension is significantly more common in obese individuals and increases the risk of heart disease, coronary artery disease, and heart attacks.

Coronary Artery Disease

Obesity disrupts glucose and lipid metabolism, increasing the risk of arterial blockages and cardiovascular complications.

Stroke

Obesity-related vascular issues can lead to reduced or blocked blood flow to the brain, resulting in stroke or brain hemorrhage.

Sleep Apnea Syndrome

A serious condition characterized by repeated interruptions in breathing during sleep, leading to fatigue and increased cardiovascular risk.

Musculoskeletal Disorders

Excess weight places strain on bones and joints, leading to orthopedic problems.

Treatment of Obesity

The primary prevention strategy is adopting healthy eating habits and an active lifestyle from childhood.

Due to its complexity, obesity treatment requires a team approach, involving physicians, dietitians, physiotherapists, psychologists, and metabolic surgery specialists.

Treatment Steps

• Lifestyle and behavioral changes
• Dietary therapy
• Exercise counseling
• Medical treatment (for comorbid conditions)
• Metabolic and Type 2 diabetes surgery

Lifestyle and Behavioral Therapy

The goal is to eliminate unhealthy habits. Even exercising for 30 minutes three times a week can significantly aid weight loss. Long-term adherence is essential to prevent relapse.

Dietary Treatment

A personalized nutrition plan is developed to regulate calorie intake and correct vitamin and mineral imbalances.

Exercise Counseling

Exercise programs are tailored individually, especially considering cardiovascular risks. Patients are encouraged to gradually adopt an active lifestyle.

Medical Treatment

Obesity itself is not directly treated with medication. Instead, medications target associated conditions such as diabetes, hypertension, and insulin resistance.

Metabolic and Bariatric Surgery

Surgical intervention aims not merely at weight loss, but at achieving a healthy body weight and resolving associated diseases.

Eligibility Criteria

• Failure of diet, exercise, and medical treatments
• BMI ≥ 40
• BMI 35–39.9 with comorbidities
• Evaluation of hormonal causes
• Suitability for surgery based on overall health

Preoperative Preparation

Patients undergo comprehensive evaluation including lab tests, imaging, specialist consultations, and anesthesia assessment. A personalized surgical plan is then created.

Mechanisms of Surgery

1. Restrictive procedures – reduce stomach size
2. Malabsorptive procedures – reduce nutrient absorption
3. Mixed procedures – combine both approaches

Types of Bariatric Surgery

• Sleeve Gastrectomy (Gastric Sleeve)
• Gastric Bypass (Roux-en-Y)
• Mini Gastric Bypass
• Transit Bipartition
• Jejunoileal Anastomosis
• Revisional Bariatric Surgery

Sleeve Gastrectomy

Performed laparoscopically, this procedure removes approximately 80% of the stomach, reducing both food intake and hunger hormone (ghrelin) levels. This leads to sustained satiety and effective weight loss.

It also has positive effects on diabetes and hypertension, often reducing or eliminating the need for medication.

Gastric Bypass

Reduces stomach size and alters intestinal absorption, making it highly effective for both obesity and type 2 diabetes.

Mini Gastric Bypass

A simpler and shorter procedure than traditional bypass, though associated with a higher risk of vitamin deficiencies.

Postoperative Period

Patients typically stay in the hospital for 4–5 days. Recovery is closely monitored, and patients transition gradually from liquids to solid foods over several weeks.

Long-term success requires:

• Adherence to dietary guidelines
• Regular exercise
• Lifelong vitamin and mineral supplementation

The goal is to achieve at least 50% excess weight loss within the first year, while maintaining long-term health and quality of life.