Global Malnutrition Prevention and Treatment Act of 2021 This bill sets out programs and otherwise directs the U.S. Agency for International Development (USAID) to carry out activities to prevent and treat malnutrition globally. Specifically, the USAID must leverage resources to address malnutrition through the Global Nutrition Coordination Plan (an interagency effort to strengthen the impact of U.S. investments in nutrition) and its role on the board of directors of the International Development Finance Corporation. The USAID must also select countries based on specified malnutrition-related indicators for purposes of targeting malnutrition prevention and treatment programs and update the selection within five years. Additionally, the USAID may establish the Nutrition Leadership Council to coordinate activities to prevent and treat malnutrition across the agency; target resources and nutrition interventions to the populations most susceptible to severe malnutrition and otherwise support efforts to prevent and treat malnutrition globally; and coordinate activities among partner countries, United Nations agencies, civil society, private sector actors, and others to, for example, build capacity in partner countries to sustain nutrition interventions. The bill also requires the USAID to provide to Congress an implementation plan and annual reports concerning its programs for treating and preventing malnutrition. The bill's provisions terminate seven years after its enactment.