What is Obesity?

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health (WHO-definition). As Overweight or obesity are rather vague terms, the World Health Organization (WHO) has defined obesity categories based on the BMI (Body Mass Index). The BMI is defined as follows:

BMI= weight (kg) / height (m) ^2

A normal weight patient has a BMI between 18.5 and 25kg/m2. 

Obesity Categories:

BMI 25-30kg/m2: Overweight

BMI 30-35kg/m2: Obesity Grade I

BMI 35-40kg/m2: Obesity Grade II

BMI above 40kg/m2: Obesity Grade III

There are many factors leading to obesity. Most commonly an excessive food intake, lack of physical activity and genetic predisposition are present. Food composition, especially a diet containing high levels of sugar or a generally unbalanced diet, rich in carbohydrate and fat, plays an important role. In recent years many other contributing factors have been identified. One example is the microbiome. The microbiome represents all bacterial and fungal species that we can find as normal parts of our intestinal flora. These species play an important role in the digestion of food and vitamins and are mandatory for our body. However the composition of this microbiome varies in between individuals. Recent findings have shown, that there are differences in the composition of this microbiome in healthy non obese and obese patients. Furthermore in obese patients metabolic and humoral (i.e. hormones that are produced in the gut) changes have been found. These changes might partially explain, why a long lasting weight loss is very difficult to achieve without surgery. 


Why is Obesity dangerous?

Obesity is commonly seen as a mainly aesthetic problem. Many obese persons telling that they feel well and are completely healthy might underline this view. Sadly obesity is not a healthy condition! Many diseases are strongly associated with obesity. The most important is certainly Type 2 Diabetes mellitus. Among many other associated conditions, the most important are:

Type 2 Diabetes

Arterial Hypertension


Bone and joint problems

Gastroesophageal Reflux Disease (GERD)

Obstructive Sleep Apnea

Increased risk of cancer (Breast, Colon, Prostate, Uterus, Lymphoma etc)



These associated diseases result in a higher risk for cardiovascular disease, cancer and other serious health conditions. Overall obesity not only impairs the quality of life for patients, but results in a significantly shorter life expectancy as well! 


Obesity Treatment

Obesity is caused by multiple factors. Therefore there is not one simple fix that might cure it. Simple diets might work for a certain time and might in some cases deliver impressive short time results. The goal of an optimal obesity treatment should be focused on long term weight loss, prevention of secondary weight regain and resolution of obesity associated comorbidities.

Goal: Sustained weight loss an resolution of co-morbidities


Conservative Treatment

The conservative treatment of obesity consists of a multidisciplinary approach to the patient. Eating habits are analyzed by a nutritional specialist and an individual diet plan is tailored for the patient. Physical activity should be increased. This is supported by an individualized training plan provided by specialized physiotherapists. All medical treatments are analyzed and changed if needed (e.g. anti-diabetic drugs, etc). Follow-up visits with your physician are assuring that the treatment plan is followed or are adapted if indicated. 

%Excessive BMI loss: Frequently used value to express the achieved weight loss. The value expresses how much of the overweight has been lost, based on the BMI of the patient. As a reference a normal BMI is 25kg/m2. A higher value represents a better weight loss.

Example: Patient with initial BMI of 45kg/m2. Two years after surgery his BMI is 33kg/m2. This results in an excessive BMI loss of 12 points (45-33kg/m2). The remaining excessive BMI is 8, the according %excessive BMI loss is 60%.

A sustainable weight loss might be achieved with an optimal conservative treatment. However the resulting overall weight loss remains relatively small in most patients. 

Achieveable weight loss: approximately 0-10% excessive BMI loss. 

An optimal conservative treatment is also the ideal preparation for surgical therapy!


Surgical Treatment

Bariatric surgery as has been shown to be the most effective treatment for obesity. It is superior to every conservative or medical treatment in terms of weight loss, sustainability of weight loss and remission of comorbidities. There are many different types of surgery available today. Not all of them have proved to be safe and effective! 

Surgical techniques can grossly be categorized by their underlying mechanisms. The two main mechanisms resulting in weight loss are restriction and malabsorption.

Restriction means that the possible food intake is limited due to surgical alterations of the anatomy. This can be achieved by diminishing the volume of the stomach. Typically this mechanism is found in the Gastric Banding or when implanting other devices (Gastric balloon, Bari-Clip etc).

Malabsorption means that not all nutrients can be absorbed. Our nutrition consists from macronutrients (proteins, carbohydrates, fat) and micronutrients (vitamins, minerals). Malabsorptive procedures reduce the body's capability of absorbing nutrients by shortening the length of the small bowel that participates in the process of absorption.   

In recent years more mechanisms have been discovered. Especially changes in the microbiome and in the humoral response to food intake seem to be very important factors, especially regarding the remission of obesity related comorbidities. It has been shown, that the microbiome changes its composition after surgery, resulting in a normal composition, identical to healthy peers within the first months. The restitution of a normal humoral response is occurring even faster after surgery. These changes can be measured a few hours after the intervention. The humoral effects of bariatric surgery might be the most important factor leading to resolution of comorbidities after surgery. Especially the impressive remission rates of Type 2 Diabetes seems to be linked to these effects. These very important mechanisms however are not found in all bariatric procedures! 

Purely restrictive procedures have a very limited long term success rate. The intra gastric balloon can only achieve a temporary weight loss while in place. Immediate rebound effects are observed after removal of the device. The Gastric Band shows better results in term of long term weight loss (approximately 30% excessive BMI loss). There are many potential problems associated with the Gastric Band, especially esophageal dismotility, band migration or band slippage. Due to the overall unfavorable results, the Gastric Band has been mainly abandoned.

The Roux-en-Y Gastric Bypass represents the golden standard in bariatric surgery. It has been described first in the 1960s and has since gained popularity worldwide. It combines the mechanisms of restriction (formation of a small gastric pouch) and malabsorption (partial bypassing of small intestine and complete bypassing of the residual stomach) without putting the patient at a risk for severe malabsorption. Furthermore the humoral effects are very strong in this procedure. Overall the Roux-en-Y Gastric bypass results in long term weight loss (approximately 70% excessive BMI loss) and resolution of comorbidities. 

The Sleeve Gastrectomy is the second well established standard bariatric procedure today. In this procedure the largest part of the stomach is resected, resulting in restriction. Due to the partial resection of the stomach, effects on the humoral system are present as well. These effects are almost identical to these found after Roux-en-Y Gastric Bypass. Accordingly the long term weight loss is comparable to a Roux-en-Y Gastric Bypass (approximately 65-70% excessive BMI loss).

The Omega-Loop Bypass is a newly developed procedure that is similar to the Roux-en-Y Gastric Bypass. The main differences are the lack of a second anastomosis and a longer biliopancreatic limb. The longer biliopancreatic limb of this bypass results in a higher grade of malabsorption, but might also benefit an even stronger humoral effect. As this procedure is still under evaluation, it can't be considered a standard procedure yet.

The biliopancreatic diversion represents a very distal gastric bypass. By excluding most of the small intestine from absorption it results in severe malabsorption. This procedure shows excellent results in terms of long term weight loss (Excessive BMI loss of approximately 85%) and resolution of comorbidities. However important side effects must be taken into account. Therefore this operation is considered for highly selected patients only. In most cases it is performed as a second line therapy after initial Sleeve Gastrectomy in super-obese patients (BMI above 60). 

Gastric banding, gastric balloon: Pure restriction, no malabsorption, no humoral effects

Sleeve Gastrectomy: Restriction, very limited malabsorption, important humoral effects

Roux-en-Y Gastric Bypass: Limited restriction, malabsorption and important humoral effects

Omega-Loop Bypass: Limited restriction, important malabsorption, important humoral effects

Biliopancreatic Diversion: Limited restriction, very important malabsorption, very important humoral effects

You can watch procedures performed by our team on our youtube channel. We present not only simple primary cases but also more complex and revisional cases. Please make sure to subscribe to our channel to stay updated!


Follow-up after Surgery

After every bariatric surgery a close follow-up is necessary. By following the patients we can identify possible long term complications (e.g. Vitamin deficiencies, other nutritional deficiencies, excessive skin, etc). The goal of this follow-up is to prevent any longterm side effects that might be identified and treated. Overall this results in better results for our patients!

We provide a follow-up program fo all our patients directly in our center!

After all bariatric procedures a lifelongMulti-Vitamin supplementation is mandatory!

Contact us:
E-mail: info@swiss-obesity.com
Phone number: +41 (0)44 720 03 55

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