A gastric balloon devices and systems (8) for occupying space within a stomach of a patient are disclosed. In one embodiment, such a gastric balloon device (8) includes a shaft element (14) for insertion into a stomach (52) of a patient and a generally elongated balloon element (12) having at least one pleat region (30). Methods of use of a gastric balloon device or system are also disclosed. For example, a gastric balloon system (8) is provided including a generally elongated balloon element (12), wherein the balloon element (12) includes at least one pleat region (30). Further, the balloon element (12) is furled and inserted through a stoma into the stomach (52) of the patient and at least partially expanded. In another method a balloon element (12) is inserted into a stomach (52) of a patient, wherein a stoma is formed nearer to a duodenum (55) than a fundus region of the stomach (52), and the balloon element (12) is at least partially expanded.