In women, fatty tissue is mostly found underneath the skin. It is referred to as subcutaneous adipose tissue (SAT) and an excess of it is referred to as “gynoid obesity”.
In men, fatty tissue is mostly found in the abdomen, between the internal organs. It is referred to as visceral adipose tissue (VAT) and an excess of it is referred to as “android obesity”. This is important, as often excess fat between the organs reduces the mobility of the intestine and the ability to perform a gastric bypass.
Management of obesity
Overweight and obesity.
Overweight and obesity are a major, growing issue in the world, and particularly in Belgium. The latest national values show that 49.3% of Belgian adults were overweight (BMI ≥25kg/m²) and 15.9% were obese (BMI ≥30kg/m²) in 2018.
Obesity surgery is growing fast and represents a significant portion of all interventions carried out in Belgium.
For example, in Belgium, between 2007 and 2017, 106,679 patients underwent bariatric surgery (i.e. approximately 1% of the Belgian population). [source: KCE 2020]
The consequences of obesity are numerous and serious: reduced self-esteem, quality of life and life expectancy by several years.
Some examples of diseases associated with obesity:
- Type 2 diabetes and hypercholesterolemia
- Cardiovascular diseases such as arterial hypertension and myocardial infarction
- Respiratory diseases such as sleep apnea syndrome and chronic respiratory failure
- Joint diseases such as osteoarthritis
- Liver diseases such as hepatic steatosis (fatty liver) and gallbladder stones
- Depression
- Infertility
- Certain cancers
Goals of bariatric surgery for obesity:
- Increase life expectancy by several years [Adams et al., NEJM 2007].
- Improve quality of life by reducing the severity or eliminating comorbidities such as type II diabetes [Buchwald et al., Am J Med 2009], sleep apnea syndrome, arterial hypertension, NASH (non-alcoholic steatohepatitis or “fatty liver”) and the incidence of certain cancers.
- Improve the psychological, economic and social consequences of obesity.
To evaluate the result of bariatric surgery, we don’t calculate total weight loss, as the ideal weight is very dependent on height. Instead, we calculate the percentage of excess weight loss (EWL%) or the percentage of excess BMI loss (EBMIL%).
EWL% represents the percentage loss of weight necessary to reach a 25 kg/m² BMI (best life expectancy). It is a better reflection of post-treatment weight loss.
For example, if your BMI is 40 and you need to lose 30kg to reach a BMI of 25 kg/m², a 15 kg loss would correspond to a 50% EWL and a 30 kg loss would correspond to a 100% EWL. It is possible to calculate statistical expected weight loss after the different types of obesity surgeries.
The goal of bariatric surgery is to bring you closer to this BMI goal of 25 kg/m², in order to increase your life quality and life expectancy. It is exceptionally rare to achieve a BMI of 25 kg/m² with this type of surgery. The reference values are usually 60-70% EWL for gastric bypass, 50% for sleeve gastrectomy and 40% for gastric banding. Losing too much weight too quickly can potentially be dangerous, and should be addressed urgently in an obesity clinic consultation. Classically, we observe a continuous weight loss during the first 6 months, then a slight increase in weight before a long term stabilization.
What is obesity?
Energy uses by the human body are distributed as follows: 60% for vital activities, 10% for heat production and 30% for physical activity.
Reducing obesity treatment to a single surgical intervention, without an integrated approach, would be a tremendous mistake. Obesity is a multifactorial and complex disease necessitating a global approach. In obesity, a number of mechanisms are involved simultaneously, such as chronic inflammation of the fatty tissue, significant hormonal changes, intestinal flora disruption (dysbiosis), immune changes, etc. gradually setting into some sort of vicious cycle. To maximize the chances of success of bariatric surgery, it is necessary to understand the numerous factors at play and consider their impact before and after the surgery.
Energy use and hunger regulation are centralized in the brain, and involve complex hormonal interactions and feedback mechanisms from fatty tissue and the digestive tract. Nervous signals from the digestive system (autonomous nerves transiting through the brainstem) as well as signals from the hypothalamus help regulate appetite. Hormones such as leptin, anorectic hormone (produced by fatty tissue), ghrelin (produced by the stomach), insulin, and others influence food intake.
What are the factors that lead to obesity?
Dietary factors
(Compulsive) Over-eating, snacking, poor nutrition (excess fat or sugar intake), etc. Optimal management of hunger and education about nutrition are essential for the success of bariatric surgery. The date of the intervention will be adjusted depending on the dietary improvements, in order to obtain better operative results.
It is essential to be able to recognize and respect feelings of hunger and fullness in order to maintain a stable weight. Poor management of these sensations can lead to regaining the weight lost after bariatric surgery Strict diets causing enhanced feelings of hunger are most often followed by a greater weight gain.
Psychological factors
Depression, stress, taking refuge in over-eating to distance oneself from negative emotions, etc. Eating disorders associated with obesity should imperatively be addressed preoperatively in order to achieve an optimal management of obesity, to improve the outcome of bariatric surgery and avoid regaining weight.
Our team offers lifelong follow-up, if necessary, and specialized psychiatric care is discussed case-by-case.
Sedentary lifestyle
Sedentary professions, long commutes leading to overconsumption of highly caloric or processed foods, excessive use of screens, etc.
Environmental factors
Food opulence (buffets), cultural factors, access to cheap take-away, living alone, lack of cooking knowledge, etc.
Hormonal influences
Quitting smoking, puberty, pregnancy, menopause, etc.
Endocrine and genetic diseases
Exceptionally (<1% of cases) responsible for severe obesity. Screening by an endocrinologist is nonetheless systematically carried out by an endocrinologist preoperatively.