Abstract: A device for treating obesity in humans is described, with a balloon arrangement that can be introduced into the human stomach and that can be filled with a fluid and emptied inside the stomach for controlled reduction of the stomach volume; with at least one fluid line, which is connected in a fluid tight manner to the balloon arrangement and via which the balloon arrangement can be filled and emptied transcutaneously; with at least one securing means provided along the fluid line in order to fix the fluid line to skin and tissue layers enclosing the stomach; and with at least one valve unit provided along the fluid line.