Various mechanisms for reducing food waste in a food waste disposer are disclosed. In each of the reduction mechanisms, structures are provided for shearing food waste as it passes through or past a rotating shredder plate of the disposer. In one embodiment, the reduction mechanism has a rotatable plate coupled to a rotational source and positioned for rotation relative to an inner wall of a stationary ring. The plate has a fixed lug attached to the rotatable plate and has a movable lug attached to the rotatable plate. In another embodiment, the reduction mechanism includes a rotatable plate coupled to a rotational source and a stationary plate disposed adjacent the rotatable plate. The stationary plate or impeller defines a plurality of apertures therethrough. At least one first portion of the rotatable plate or impeller shears over at least some of the apertures in the stationary plate to shear the food waste.