Methods and systems for sizing fat parcels are provided. In particular, a parcelizer device that includes a container and a displacement insert or filter element is provided. Tissue containing fat parcels is passed through the parcelizer. The parcelizer can include multiple displacement inserts or filter elements. Alternatively or in addition, a plurality of displacement structures that each include one or more displacement inserts or filter elements can be provided. In general, the displacement inserts or filter elements are configured to progressively reduce the size of fat parcels included in tissue.
