There is no data available in the UAE regarding the impact of bariatric surgery on metabolic, nutritional and psychological status of the patient. Therefore, studying that will help the community in establishing a database specific for the country instead of relying on other countries statistics and data.

In 2009, figures from WHO have revealed that 39.9% of women in United Arab Emirates (UAE) are obese which considered the 7th highest proportion in the world. On the other hand, 25.6% of men are obese in UAE which considered the 9th highest proportion in the world.

The search for ideal weight loss operation started more than 50 years ago. First bariatric surgery performed in 1954 by Kremen and his associates which involved the anastomosis of upper and lower intestine that bypasses large amount of absorptive circuit. Mason, Ito et al. developed the Gastric Bypass in 1967, which led to fewer complications than the intestinal bypass. A later improvement, the Roux-en-Y Gastric Bypass, proved technically difficult to perform but led to long-term sustained weight loss, no protein-calorie malabsorption and little vitamin or mineral deficiencies. Many studies and researches are conducting studying the impact of bariatric surgery on different health parameters.

There are many studies regarding the effect of bariatric surgery on diabetic and metabolic parameters. Study of 15 patients with Body Mass Index (BMI) between 30-35 kg/m2 with type II diabetes underwent Roux-En-Y gastric bypass with 1 year follow up. Results that diabetes mellitus remission achieved in 93% of cases with significant drop in blood glucose and HbA1C (p≤ 0.05 \& p ≤ 0.001) respectively. Another study, 17 obese patients with type II diabetes mellitus (DM) received the duodenal-jejunal bypass liner followed for 24 weeks. HbA1C improved from 8.4±0.2 to 7.0±0.2% (p≤0.01). A third study regarding the effect of laparoscopic Roux-En-Y gastric bypass (LRYGBP) on (Diabetes mellitus II) DMII for period of 5 years. 1160 patients underwent LRYGBP and 240 (21%) has impaired fasting glucose (IFG) or DMII. Body mass index (BMI) decreased from 50.1 to 34 kg/m2. Hemoglobin A1C (HbA1C) returned to normal levels (83%) or markedly improved (17%) in all patients. Reduction in use of oral anti-DM (80%) and insulin (79%) followed surgical treatment. Furthermore, in other study 52 morbidly obese patients were studied after sleeve gastrectomy. HbA1C changed form 6.0 ± 1.3% to 5.4 ± 0.8% to 5.4 ± 0.8% at 6 and 12 months respectively. Triglyceride decreased from 159± 87 to 116± 41 and 116± 62 mg/dl, while High density lipoprotein (HDL) increased from 46± 12 to 50 ±12 and 56±13 mg/dl at 6 and 12 months. There is a study of 100 obese patients after laparoscopic adjustable gastric banding and the influence on body mass index (BMI), insulin concentration and lipid profile. Results include significant decrease in BMI, normalization of metabolic parameters, with improvement of type II DM, Hypertension (HTN), and sleep apnea.

There is a study about improving renal function 12 months after bariatric surgery. They studied changes in Glomerular Filtration Rate (GFR) before and 1 year after the surgery in 223 severely obese patients. Normal GFR was 90-125 ml/min. They found that GFR increased in patients with previously normal, Chronic kidney disease (CKD) stage II and CKD stage III. Another 12- month prospective study, regarding the effect of bariatric surgery on renal function and systemic inflammation and blood pressure. A total of 34 morbidly obese patients were investigated at baseline, 1 month and 12 months after Roux-En-Y gastric bypass. The results showed a significant decrease in body mass index (BMI), mean arterial pressure, and urinary and serum inflammatory markers (all p≤0.001). There are many studies in the literature regarding improving quality of life (QoL) after bariatric surgery. There was a study in which obese patient's QoL was investigated early and medium-term changes following Roux-en-y gastric bypass.

There was a study regarding the sexual function post bariatric surgery. In a prospective study of 39 men underwent bariatric surgery. Their sexual function was assessed by mean of international index of erectile function (IIEF) before and 1 year after the surgery. In addition to, metabolic and hormonal parameters (like weight, HbA1C, lipoid profile, insulin sensitivity and sex hormones). They found that erectile function score improved from baseline of 54.85 ± 16.59 to 61.21 ± 14 with P ≤ 0.01 and gonadal function including testosterone level(from 256.36 ± 120.98 in baseline to 508.01±161.90 with P ≤0.01 at 1 year.

There are many studies regarding the nutritional deficiency following bypass surgeries. There is a study of long-term nutritional deficiencies and dietary intake after sleeve gastrectomy or Roux-En-Y gastric bypass in a mediterranean population. It was a longitudinal, prospective and observational study in which primary outcomes were changes in energy, macronutrients, and micronutrients intake and weight loss. They found that the mean daily intake of calcium, magnesium, phosphorus, and iron was less than the current recommendations. The most common observed deficiency is 25-hydroxy vitamin D. On the other hand, there are 2 case reports of night blindness and visual impairment caused by vitamin A deficiency after bariatric surgery which considered a significant complication after mal-absorptive bariatric surgery. Moreover, there is a prospective, single-center, observational study regarding nutritional deficiencies following sleeve gastrectomy with a medium follow up of 2 years. From 100 patients were studied, 48% were supplemented with iron, 33% with zinc, 34% with a combination of calcium carbonate + cholecalciferol, 24% with vitamin D, 42% with vitamin B12, and 40% with folic acid. The patients who received only a sleeve gastrectomy had (Excess weight loss % EWL) of 53.6%, 65.8% and 62.6% after 6, 12 and 24 months, respectively.