الفهرس 
Techniques in measurement of obesityOnly 14 pages are availabe for public view
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Abstract
Obesity has become major health problem in both developed and developing nations, because of its high prevalence and causal relation- ship with serious medical and psychological complications, such as diabetes, hypertension, and hyperlipidemia. Diabetes, in particular, is strongly associated with obesity: the prevalence of diabetes was 3% among individuals of healthy weight, 6% among over weight individuals, 11% among obese individuals, and 19% among the extremely obese.
Little is known about the aetiology of obesity. There are propably spectrum of different kinds of disorders as genetic, environmental or both which increase intake, decrease expendature of an obese individual.
Obesity is typically evaluated in absolute terms by measuring body mass index (BMI) but also in terms of its distribution through waist circumference or waist-hip circumference ratio measurements.According to BMI, obesity is defined as 30 Kg/m2 over desirable weight and morbid obesity is defined as BMI over 40 Kg/m2. More recently, another category, super obesity has been defined as BMI greater than 50Kg\m2 over desirable weight.
The risk of metabolic complications and comorbid factors is related to both BMI and waist circumference specifically the risks of hypertension (3.0 times higher) and risks of diabetes mellitus (2.9 Times higher) and risk of atherosclerosis (1.5 times higher).
Effective weight loss therapy can reverse many of the adverse effects of severe obesity. Available therapies include lifestyle changes (diet and exercise), very-low-calorie diets, pharmacologic therapy, and surgery. Of these, bariatric surgery is documented as the most consistently effective therapeutic intervention for the severely obese.
Surgery is usually successful in inducing substantial weight loss in the majority of obese patients with improvement or reversal of obesity-related comorbidities and is achieved primarily by an inevitable reduction in energy intake.
With the increasing use of surgery to treat massively overweight patients in the 1980s, the National Institutes of Health (NIH) proposed that bariatric surgery should be considered for persons with a body-mass index of more than 40 or of more than 35 in patients with coexisting illnesses. It also concluded that bariatric surgery was appropriate only if other forms of treatment had failed.
Bariatric surgical procedures can be categorized as malabsorptive, restrictive, or combined, based on their effects on the digestive system. Biliopancreatic diversion (BPD) and BPD with duodenal switch (BPD/DS) are malabsorptive, laparoscopic adjustable gastric banding (LAGB) is restrictive, and Roux-en-Y gastric bypass (RYGB) combines both malabsorptive and restrictive features.
With open procedures of bariatric surgery patients are more likely to experience a postoperative complication than those undergoing laparoscopic surgery. Patients were significantly more likely to experience pulmonary complications, cardiovascular complications, sepsis, and anastomotic leak. In addition laparoscopic procedures cause reduction in abdominal wall complications and a shorter hospital stay. The midterm weight loss is similar with both techniques.
One inconvenience is that laparoscopic procedures have a more complex learning curve which may be associated with an increase in postoperative complications. Experience of the surgeon and surgical team and providing preoperative and postoperative support is critical to the success of bariatric surgery.
The most commonly performed procedures for morbid obesity at this time are RYGB, LAGB, and SG. Each procedure has advantages and disadvantages.The appropriate choice of operation begins with a full assessment of the patient’s reasons for choosing as well as expectations of weight loss surgery. Information can then be gathered from the history and physical examination, laboratory data, imaging and endoscopic studies, and prior operative notes. Arbitrarily, choice of procedure can be determined by weight, presence of comorbid illness, age, and relevant previous surgery.
Complications of bariatric surgery could be classified into surgical and nutritional complications.Surgical complications include DVT, pulmonary embolism, Gastrointestinal leaks, acute gastric dilatation, Stomal ulceration, Stomal stenosis and Mechanical bowel obstruction.