At least one of a plurality of disorders of a patient characterized at least in part by vagal activity innervating at least one of a plurality of organs of the patient is treated by a method that includes positioning an electrode on a vagus nerve. An electrical signal is applied to the electrode to modulate vagal activity by an amount selected to treat the disorder. In some embodiments, the disorder is obesity. The signal may be a blocking or a stimulation signal. In some embodiments, the signal is selected to, at least in part, downregulate neural activity on the vagus nerve. In embodiments, a system comprises a band comprising a first electrode array and a second electrode array; a signal generator electrically connected to each of said first, and second electrode array; an external programmer configured to: communicate at least one parameter for the neural conduction blocking signal to the implantable controller, wherein the parameter is selected for the neuroconduction blocking signal to i) at least partially downregulate the vagus nerve, ii) allow at least partial recovery of the nerve activity following discontinuation of the neural conduction blocking signal, and iii) reduce pancreatic and biliary output via inhibition of pancreo-biliary output; and an external coil.