Background: The association of body mass index and gastroesophageal reflux disease (CERD), including its complications (esophagitis, Barrett esophagus, and esophageal adenocarcinoma), is unclear. Purpose: To conduct a systematic review and meta- analysis to estimate the magnitude and determinants of an association between obesity and GERD symptoms, erosive esophagitis, Barrett esophagus, and adenocarcinoma of the esophagus and of the gastric cardia. Data Sources: MEDLINE search between 1966 and October 2004 for published full studies. Study Selection: Studies that provided risk estimates and met criteria on defining exposure and reporting outcomes and sample size. Data Extraction: Two investigators independently performed standardized search and data abstraction. Unadjusted and adjusted odds ratios for individual outcomes were obtained or calculated for each study and were pooled by using a random- effects model. Data Synthesis: Nine studies examined the association of body mass index (BMI) with GERD symptoms. Six of these studies found statistically significant associations. Six of 7 studies found significant associations of BMI with erosive esophagitis, 6 of 7 found significant associations with esophageal adenocarcinoma, and 4 of 6 found significant associations with gastric cardia adenocarcinoma. In data from 8 studies, there was a trend toward a dose- response relationship with an increase in the pooled adjusted odds ratios for GERD symptoms of 1.43 (95% CI, 1.158 to 1.774) for BMI of 25 kg/m2 to 30 kg/m2 and 1.94 (CI, 1.468 to 2.566) for BMI greater than 30 kg/m 2. Similarly, the pooled adjusted odds ratios for esophageal adenocarcinoma for BMI of 25 kg/m2 to 30 kg/m2 and BMI greater than 30 kg/m2 were 1.52 (CI, 1.147 to 2.009) and 2.78 (CI, 1.850 to 4.164), respectively. Limitations: Heterogeneity in the findings was present, although it was mostly in the magnitude of statistically significant positive associations. No studies in this review examined the association between Barrett esophagus and obesity. Conclusion: Obesity is associated with a statistically significant increase in the risk for CERD symptoms, erosive esophagitis, and esophageal adenocarcinoma. The risk for these disorders seems to progressively increase with increasing weight. Background: The association of body mass index and gastroesophageal reflux disease (CERD), including its complications (esophagitis, Barrett esophagus, and esophageal adenocarcinoma), is unclear. Purpose: To conduct a systematic review and meta- analysis to estimate the magnitude and determinants of an association between obesity and GERD symptoms, erosive esophagitis, Barrett esophagus, and adenocarcinoma of the esophagus and of the gastric cardia. Data Sources: MEDLINE search between 1966 and October 2004 for full studies. Study Selection: Studies that provided risk estimates and met criteria on defining exposure and reporting outcomes and sample size. Data Extraction: Two investigators optionally committed standardized search and data abstraction. Unadjusted and adjusted odds ratios for individual outcomes were obtained or calculated for each study and were pooled by using a random-effects model Data Synthesis: Nine studies examined the association of body mass index Six of these studies found significant associations of BMI with erosive esophagitis, 6 of 7 found significant associations with esophageal adenocarcinoma, and 4 of 6 found significant associations with gastric cardia adenocarcinoma . In data from 8 studies, there was a trend toward a dose-response relationship with an increase in the pooled adjusted odds ratios for GERD symptoms of 1.43 (95% CI, 1.158 to 1.774) for BMI of 25 kg / m2 to 30 kg / m2 and 1.94 (CI, 1.468 to 2.566) for BMI greater than 30 kg / m2 2. Similarly, the pooled adjusted odds ratios for esophageal adenocarcinoma for BMI of 25 kg / m2 to 30 kg / m2 and BMI greater than 30 kg / m2 were 1.52 (CI, 1.147 to 2.009) and 2.78 (CI, 1.850 to 4.164), respectively. Limitations: Heterogeneity in the findings was present, although it was mostly in the magnitude of significant significant positive associations. No studies in this review examined the association between Barrett esophagus and obesity. Conclusion: Obesity is associated with a significant apoptosis in the risk for CERD symptoms, erosive esophagitis, and esophageal adenocarcinoma. The risk for these disorders seems to progressively increase with increasing weight.