A method of reducing gastric volume in a portion of a gastrointestinal tract having a longitudinal axis. The method comprises repeating a stimulation cycle comprising the steps of stimulating the gastrointestinal tract at a first location for a first stimulation period and stimulating the gastrointestinal tract at a second location on for a second stimulation period. In the disclosed method the first and second locations are axially spaced from each other along the longitudinal axis and the first and second stimulation periods are sufficient to maintain a gastric volume reduction in the portion of the gastrointestinal tract at least during the stimulation cycle.