A food intake restriction device for forming a restriction in a patient's gastro-intestinal tract and non-invasively communicating pressure data regarding the restriction to an external monitor. The device includes a food intake restriction device implanted substantially about a patient's gastro-intestinal tract to form a restricted opening in the tract. A port is connected to the restriction device. The port contains a working fluid for affecting the size of the restricted opening. A pressure sensing system communicates with the working fluid to measure the pressure of the working fluid. A transmitter communicates the measured fluid pressure to the external monitor.