During the sixty-day review period established in paragraph (1), the Secretaries shall review and approve or disapprove such guidance to assure that the guidance either is consistent with the “Dietary Guidelines for Americans” or that the guidance is based on medical or new scientific knowledge which is determined to be valid by the Secretaries. If after such sixty-day period neither Secretary notifies the proposing agency that such guidance has been disapproved, then such guidance may be issued by the agency. If both Secretaries disapprove of such guidance, it shall be returned to the agency. If either Secretary finds that such guidance is inconsistent with the “Dietary Guidelines for Americans” and so notifies the proposing agency, such agency shall follow the procedures set forth in this subsection before disseminating such proposal to the public in final form. If after such sixty-day period, either Secretary disapproves such guidance as inconsistent with the “Dietary Guidelines for Americans” the proposing agency shall—