The teachings are directed to an intragastric device comprising a flexible and expandable bladder having a predetermined shape upon expansion for contacting the antrum of the stomach of a subject. The device is designed to avoid passage of any part of the device beyond the pylorus and lower esophageal sphincter while the bladder is expanded during use. In these embodiments, the bladder can contain a high specific gravity material when expanded wherein, the high specific gravity material contributes to an in vivo specific gravity of the device that ranges from about 1.2 g/ml to about 2.1 g/ml and functions to direct the device to the pyloric antrum of the subject during use of the device. Moreover, these embodiments can include a filling material comprising a biocompatible fluid component and a hydrogel component to make the device substantially leakproof and contribute to the in vivo specific gravity of the device.
