The Secretary is authorized to establish in accordance with chapter 10 of title 5 such advisory committees as he may deem appropriate to assist in the performance of his functions. Members of such advisory committees, other than full-time employees of the Federal Government, while attending meetings of such committees or while otherwise serving at the request of the Secretary while serving away from their homes or regular places of business, may be allowed travel expenses, including per diem in lieu of subsistence, as authorized by section 5703 of title 5 for individuals in the Government serving without pay.