Devices are described that are adapted and configured for use within the duodenum of a mammal. One aspect of the device includes a spine having a proximal end and a distal end an atraumatic feature positioned on at least one of the proximal end and the distal end of the spine and a flow reduction element positioned along the spine and having a variable porosity along its length. In another aspect, there is a flow reduction device adapted and configured for use within the duodenum of a mammal having a spine having a length, a proximal end and a distal end a first atraumatic feature positioned adjacent to the spine proximal end a second atraumatic feature positioned adjacent to the spine distal end wherein the length of the spine is selected so that when the first atraumatic feature is in the stomach the second atraumatic feature is in the fourth portion of the duodenum and a flow reduction element having a proximal end, a distal end, an interior portion, an exterior portion and a variable porosity between the proximal end and the distal end. Additionally or alternatively, some or all of the components of the device may be formed from or coated with a lipid-philic material. There is also provided a method for adjusting the passage of ingesta through the duodenum of a mammal. The method includes placing the distal end of a flow reduction device in the duodenum of a mammal placing the proximal end of the flow reduction device in a stomach of the mammal expanding within the duodenum of the mammal a variable porosity flow reduction element supported by the flow reduction device and directing at least a portion of the flow of ingesta through the duodenum through the proximal end of the variable porosity flow reduction element and into an interior portion of the variable porosity flow reduction element.Cette invention concerne des dispositifs conçus et configurés pour être utilisés à lintérieur du duodénum dun mammifère. Un aspect du dispositif comprend une colonne vertébra
