Obesity is defined by body mass index (BMI). It is a medical condition in which the excess body fat accumulates to the extent that it can have negative effect on health, leading to a reduced life expectancy and several health problems. However, weight loss surgery is recommended if you cannot lose weight and are keeping it off by maintaining a healthy diet, and lifestyle. Doctors often use BMI and other health conditions like Type 2 diabetes and high blood pressure to determine who are the patients who are likely to benefit from weight loss surgery. The patients who are the right candidates for surgery are those with a BMI>32.5 kg/m2; those who are suffering from co-morbidities like diabetes; or patients with BMI>37.5kg/m2 (with or without associated co-morbidities).