Epidemiological study of obesity in populations of different racial, cultural, economic and dietary background

Obesity is defined as unphysiological increased fat in the body. The most commonly used criteria to assess the presence and the severity of obesity are body mass index (BMI). This worldwide health problem is one one of the most serious and prevalent non-communicable diseases of the 21st century and it is called as a global epidemy. Overweight and obesity are suffering more and more people not only in developed countries but also increasingly in developing countries. Worldwide obesity has more than doubled in the last 4 decades and it is the second of the leading preventable causes of death worldwide (after smoking). Obesity has a plurifactorial pathogenesis. The central perturbation consists in the imbalance between calories intake and calories consumption, by inappropriate diet and sedentary lifestyle. Identification of all the ethiological factors is important for treatment and prophylaxis. Obesity is common and associated with a high rate of morbidity and mortality; therefore, treatment is of great interest. At present, bariatric surgery is the only truly successful treatment of severe obesity. The field of bariatric surgery has seen a rapid evolution over the last 30 years and current procedures are safe, effective, less invasive, and relatively cost- effective. Bariatric procedures produce durable weight loss, long-term remission of type 2 diabetes, and beneficial effects on other comorbidities; they lead to a significant reduction in mortality in the long term. The adverse events after surgery are not uncommon but in majority of cases are not fatal. Bariatric surgery is costly, but cost-efficacy analysis consistently shows that the additional years of lives gained through bariatric surgery can be obtained at a reasonable and affordable cost. However, universal surgical treatment of obesity is not achievable with the world's current healthcare and surgical resources