The incidence and prevalence of gastro-oesophageal reflux disease is rising. Changing dietary habits and increasing body weight can be held responsible. In several studies a close relation was found between body weight and the occurrence of reflux disease. It may be concluded that there is a definite relation between body mass index and the occurrence of reflux disease. H. pylori probably also plays a role. H. pylori causes changes in fundic leptin levels and plasma levels of ghrelin. Eradication of H. pylori infection can increase appetite leading to a rise in body mass index due to a higher caloric intake. H. pylori can be a 'protective' factor against the development of overweight. Since only a minority of overweight or obese patients with gastro-oesophageal reflux disease will lose weight successfully, medical treatment with effective acid suppression will be the mainstay of the treatment of reflux disease in patients with a high body mass index.