Obesity is a worldwide chronic epidemic and is a strong predictor of mortality. Its prevalence continues to increase despite public health efforts of awareness. With the rise in obesity and specifically morbid obesity worldwide, there has been a pronounced increase in obesity related metabolic disorders such as type 2 diabetes mellitus, hyperlipidemia, hypertension and some others. Reduction in weight is very important to control diabetes and one of the only measures that may cure diabetes and reduce weight loss is bariatric surgery. Bariatric surgery results in weight loss and the resolution of diabetes. Studies have shown that the effect of surgical weight loss has a more pronounced effect than diet controlled weight loss. This occurs due to several metabolic changes that occur in the body. The levels of incretins significantly rise including the rise of glucagon like peptide-1 and glucose-dependent insulinotropic polypeptide. In addition, PYY 3-36 and oxyntomodulin also rise post-surgery. On the other hand, there are reductions in branched chain amino acids, aromatic amino-acids phenylalanine and tyrosine.