Regarding the relationship between MS and GI diseases, studies have reported that patients with MS are almost twice at risk for developing Barrett's esophagus. If these findings will be confirmed in prospective studies, patients with MS could form a high-risk group for developing Barett's esophagus and esophageal adenocarcinoma. The prevalence of MS concerning the development of Barett's esophagus and particularly the relationship between the length of damage and changes in the levels of leptin, insulin and proinflammatory markers, indicate that the changes caused by the development of Barrett's esophagus are constant and are affected by metabolic changes caused by adipokines and cytokines. The relationship between MS, gastro-esophageal reflux disease (GERD), and the development of IM also requires well designed prospective studies. It seems however, to be a correlation between obesity and GERD, as well as between obesity and gastric adenocarcinoma.