In 2003, Clayton was appointed Assistant Director-General and Special Adviser to the Director-General on World Food Summit Follow-up with the Food Agriculture Organization (FAO) of the United Nations in Rome, Italy. She served in that capacity for three years, in which she was responsible for encouraging the establishment of global alliances and partnerships to fight hunger and poverty in twenty-four different countries around the world, including the United States, Brazil, Ghana, and Jordan. Clayton remains a strong advocate for the hungry and the poor and she continuously promotes sustainable agriculture and equality in this country and around the world.