A system (100) for regulating absorption and caloric intake can include an elongated tube (110) having a stomach portion (114) and a lower intestine portion (116) where the elongated tube defines a passage (114) to guide ingested material through the stomach (102) and through a portion of the small intestine (104). The system also includes a non-invasive stomach stricture device (150) having a clamping structure (152) for regulating the rate of flow of ingested material through the elongated tube where the clamping structure reduces the capacity of the passage by clamping a portion of the elongated tube through the exterior of the stomach.