Gastroesophageal reflux disease (GERD) is commonly seen in Western countries; however, it is gaining prevalence in Asia countries recently. In addition to the lower esophageal sphincter and the crural fibers of the diaphragm, the flap valve at the gastroesophageal junction is also responsible for maintaining an antireflux barrier. Hill et al developed a grading system of gastroesophageal flap valve (GEFV) and concluded that this flap valve system is simple, reproducible, and offers diagnostic aid in the evaluation of patients with suspicious reflux disease undergoing esophagogastroduodenoscopy (EGD). It is a common belief that large meals provoke considerable postprandial reflux and it results from an increase in the rate of transient lower esophageal sphincter relaxations. One study also revealed that rapid food intake produces more gastroesophageal reflux in healthy volunteers. So this study attempted to evaluate the relationship between dietary habit and GEFV abnormality. The investigators used a questionnaire regarding the dietary habit to the population undergoing EGD in a self-paid health examination.