A one piece undergarment for wear on a torso and legs of a body, having at least two elastic straps extending substantially parallel to one another. A plurality of moveable panels extending along the two straps and configured as a plurality of tube portions one above another, each panel having two parallel edges extending horizontally around the body. The moveable panel is secured by at least two moveable seams, each seam creating a channel by encasing the strap from one parallel edge to the other parallel edge of the moveable panel to slide upwardly and downwardly along the body.