This study is conducted in National Cheng Kung University Hospital, a tertiary health care center in Tainan, Taiwan. All participants give written informed consent before enrollment. After panendoscopy to confirm enrollment eligibility and reflux esophagitis in Los Angeles A or B, all patients are evenly randomized into a DEX group (receiving 8-week dexlansoprazole 60 mg per day) or double-dose PPI group (receiving 8-week lansoprazole 30 mg twice daily). The enrolled patients are randomized by two series of sealed envelopes containing a prescheduled group code; one series for the overweight patients and the other for the obese patients. In each series of the sealed envelopes, the number of the group code will be equal within every 10 sealed envelopes.