A delivery system and method of use thereof for introducing an intragastric bag and filler strip into a gastric lumen are described. The delivery system includes a multi-lumen overtube, one or retractable hooks, an endoscopic looping device, and a pusher rod. The intragastric bag is attached and loaded into the overtube. The overtube is then deployed within the gastric lumen. A pusher rod pushes the distal end of the intragastric bag out of the overtube and into the gastric lumen. With the intragastric bag open, the filler strip is advanced into the intragastric bag using the pusher rod. The endoscopic loop is then tightened around the proximal end of the intragastric bag so that the filler strip remains entrapped within the intragastric bag.