Obesity & Bariatric Surgery

Medical content by Elias Tsiolis, Director Surgeon · Last updated: 11 May 2026

Obesity

Obesity is not a choice; it is a chronic disease that affects every aspect of life — physical health, mental wellbeing, social and working life. Today, however, medicine offers truly effective solutions tailored to each patient's needs.

At Athens Surgery, obesity is treated holistically, with respect, scientific guidance and an individual approach:

• Drug treatment with the latest GLP-1 medicines (semaglutide, liraglutide) and orlistat for safe weight loss without surgery.
• Bariatric surgery for definitive treatment of severe (morbid) obesity, with techniques such as sleeve gastrectomy, bypass and gastric balloon.
• Medical and psychological support, because every patient is unique and success depends on the right guidance.

Modern obesity surgery is not just about losing weight – it is about improving life, health and self-confidence.

Everything You Need to Know About Obesity

Obesity is one of the greatest challenges of modern medicine.

It is a chronic, multifactorial disease associated with excessive accumulation of body fat that affects a person's health, mental wellbeing and life expectancy.

Causes and Risk Factors

Obesity is caused by a combination of:

• Genetic factors (predisposition)
• Eating habits (excessive calorie intake, sugar, processed foods)
• Lack of physical activity
• Hormonal disorders (e.g. hypothyroidism)
• Psychological factors (stress, depression, eating disorders)
• Effects of medication (e.g. corticosteroids, antidepressants)

Health Effects

Obesity increases the risk of:

• Type 2 diabetes
• High blood pressure and cardiovascular disease
• Sleep apnea
• Osteoarthritis
• Infertility and hormonal disorders
• Certain cancers (endometrial, colorectal, breast)

Treatment

Conservative Treatment

• The first line of treatment is always conservative:
• Nutritional education from a dietitian
• More physical activity (at least 150 minutes/week)
• Psychological support
• Medication, where indicated
• Medication is most often used in patients with:
• A body mass index (BMI) ≥ 30, or
• BMI ≥ 27 with related conditions (e.g. diabetes, hypertension).
• Examples of medicines:
• Orlistat: reduces the absorption of fat in the intestine.
• Liraglutide: a GLP-1 agonist – reduces appetite and increases the feeling of fullness.
• Semaglutide: also a GLP-1 agonist, with impressive weight-loss results.
• Drug treatment requires medical supervision and is not a permanent solution unless combined with lifestyle changes.

Surgical Treatment

When obesity is severe or morbid (BMI > 40), or when conservative treatment fails, surgical treatment is indicated. Bariatric surgery offers significant, long-term weight loss and improves quality of life and related conditions.

Laparoscopic Sleeve Gastrectomy

• A large part of the stomach (about 70–80%) is removed.
• Stomach capacity and production of ghrelin (the “hunger hormone”) are reduced.
• Performed laparoscopically, with a 1–2 day hospital stay.
• A common and effective method.

Gastric Bypass (Roux-en-Y)

• A small stomach pouch is created and part of the intestine is bypassed.
• Reduces calorie absorption and boosts metabolism.
• Offers long-term results

Mini Gastric Bypass (One Anastomosis Gastric Bypass)

• A simpler variant with a single anastomosis.
• Shorter operating time and fast recovery.
• Very good weight-loss results.

Adjustable Gastric Band

• An adjustable band is placed around the upper stomach.
• Limits food intake.
• Now used less often because of lower effectiveness and frequent complications.

Gastric Balloon

• A balloon is placed in the stomach endoscopically.
• Temporarily reduces stomach volume – a non-surgical solution.
• Lasts 6 months; suitable for mild to moderate obesity.

Benefits of Bariatric Surgery

• Loss of 60–80% of excess weight
• Resolution or remission of diabetes, hypertension and sleep apnea
• Lower risk of cardiovascular disease
• Better quality of life and mental wellbeing
• Long-lasting results

Aftercare

• Success depends on:
• Medical and dietary follow-up
• Vitamin / trace element supplements with some techniques
• Establishing a balanced diet
• Physical activity

Frequently Asked Questions

Bariatric Surgery

The modern solution for morbid obesity.

Bariatric surgery is the only scientifically proven method for the long-term treatment of morbid obesity.

Its goal is not simply weight loss, but a holistic improvement in the patient's health, mental wellbeing and quality of life.

Everything You Need to Know About Bariatric Surgery

What is bariatric surgery?

The term “bariatric” comes from the Greek words “baros” (weight) and “iatros” (doctor) and describes surgical procedures that help weight loss by:

• Limiting the amount of food a person can eat (restrictive techniques).
• Reducing the absorption of calories (malabsorptive techniques).
• Or a combination of both mechanisms.

Who is a candidate for bariatric surgery?

Surgical treatment of obesity is indicated for people who meet specific medical criteria:

• BMI ≥ 40, regardless of related conditions.
• BMI ≥ 35 when conditions such as the following are present:
• Type 2 diabetes,
• Hypertension,
• Sleep apnea,
• Osteoarthritis,
• Fatty liver disease
• Failure of conservative efforts (diet, medication, psychological support).

Goals of bariatric surgery

• Loss of 60–80% of excess weight within the first 12–18 months.
• Improvement or cure of related conditions.
• Lower mortality and cardiovascular risk.
• Better self-esteem, mental balance and social life.

Treatment

Pre-operative Assessment

Bariatric surgery requires thorough preparation involving a multidisciplinary team.

• This includes
• Clinical assessment by the surgeon.
• Nutritional assessment by a dietitian.
• Psychological support to change habits.
• Hormone and blood tests.
• Imaging (ultrasound, endoscopy, X-ray examinations).
• Proper preparation reduces complications and increases success rates.

Surgical Treatment

Sleeve Gastrectomy

The most common operation worldwide. 70–80% of the stomach is removed, leaving a narrow tube (“sleeve”). As a result:

• Stomach capacity is drastically reduced.
• Appetite is reduced (because of lower levels of the hormone ghrelin).
• Digestion continues normally.

Advantages:

• Laparoscopic, minimally invasive.
• 1–2 day hospital stay.
• Fast recovery.
• Impressive weight loss.

Gastric Bypass (Roux-en-Y)

A small “pouch” is created in the upper stomach and part of the small intestine is bypassed.

The amount of food is limited and calorie absorption is reduced.

Advantages:

• Very large weight loss.
• Dramatic improvement of type 2 diabetes
• Long-term results.

Disadvantages:

• Slightly more complex technically.
• Requires lifelong vitamin supplements.

Mini Gastric Bypass (One Anastomosis Gastric Bypass)

A variant of the classic bypass with a single anastomosis. It combines restriction and malabsorption, with a shorter operation.

Advantages:

• Shorter operating time.
• Very good weight-loss results.
• Fewer complications.

Adjustable Gastric Band

An older technique in which an adjustable band is placed around the upper part of the stomach.

Today it is used less often because of limited results and frequent complications (slippage, erosion, obstruction).

Gastric Balloon

A non-surgical, endoscopic technique. A balloon is placed in the stomach to create a feeling of fullness. It stays in for 6–8 months and is removed endoscopically.

It is suitable for:

• Mild to moderate obesity.
• Preparation before surgery in patients with very severe obesity.

Benefits After Bariatric Surgery

• Permanent weight loss
• Resolution or remission of type 2 diabetes
• Lower blood pressure and cholesterol
• Resolution of sleep apnea
• Improved fertility & hormonal balance
• A psychological fresh start, self-confidence, social activity

Aftercare

Success does not end with the operation; it requires long-term follow-up.

• Hospital stay: 1–3 days.
• Return to activities: in 5–10 days.
• Diet: week 1 → liquids, weeks 2–3 → purées, after the first month → gradually solid food.
• Supplements: vitamins, iron, calcium.
• Regular check-ups (blood tests & dietitian).

Bariatric surgery is the beginning of a new life, not the end of the effort.

Frequently Asked Questions

Medical Treatment of Obesity

A new era in the treatment of obesity

Obesity is not just a cosmetic issue; it is a chronic metabolic disease that requires medical follow-up and multifactorial treatment.

In recent years, science has made impressive progress in the drug treatment of obesity, with medicines that regulate metabolism, reduce appetite and improve blood sugar control.

Everything You Need to Know About Medical Treatment of Obesity

Obesity medicines are not for everyone. They are prescribed when certain medical criteria are met:

• Body mass index (BMI) ≥ 30, or
• BMI ≥ 27 with related conditions (e.g. diabetes, hypertension, dyslipidemia).

The right medicine is chosen by a specialist doctor after a full clinical and laboratory assessment.

Treatment

Types of Medication

Modern drug treatment mainly targets two mechanisms:

• Reducing fat absorption
• Regulating appetite and fullness through the central nervous system

Main Approved Medicines

Orlistat

• Reduces the absorption of fat from the intestine by up to 30%.
• Does not affect the central nervous system; acts locally in the gut.
• Weight loss of 5–10% of starting weight in 6–12 months.
• Side effects: mild gastrointestinal (oily stools, wind).

Liraglutide

• A GLP-1 receptor agonist.
• Given as a subcutaneous injection once a day.
• Significantly reduces appetite and slows stomach emptying.
• Leads to an average loss of 8–10% of starting weight.
• Also approved for patients with type 2 diabetes.

Semaglutide (Ozempic / Wegovy)

• A newer GLP-1 agonist, given as one injection a week.
• Offers impressive results: loss of up to 15–20% of starting weight.
• Regulates appetite, glucose and metabolism.
• Considered the most effective non-surgical treatment for obesity.
• Can serve as a pre-operative stage before bariatric surgery.
• They mimic the action of the natural hormone GLP-1, which:
• is released after eating,
• regulates blood sugar levels,
• and slows digestion.
• Result:
• Lower calorie intake
• Activated metabolism
• A feeling of fullness and mental balance
• GLP-1 therapies are changing the treatment of obesity, offering impressive results without surgery.

Combination with Bariatric Surgery

• Drug treatment is often used:
• Before surgery, to reduce risk and weight.
• After surgery, in case of minor weight regain.
• Cooperation between doctor, dietitian and psychologist remains essential.

Advantages of Medical Treatment

• Weight loss without surgery
• Easy to use (daily or weekly dose)
• Significant improvement in glucose and lipids
• Suitable for patients with mild to moderate obesity
• Can be combined with psychological & dietary support

Limitations

• Weight loss is less permanent than with bariatric surgery.
• Requires discipline and medical follow-up.
• May cause mild side effects (nausea, indigestion, fatigue).

Frequently Asked Questions