A healthy, productive life requires adequate nutrition. However, two billion people in the world, including nearly 200 million children under 5 years, suffer from undernutrition and its permanent consequences on health, well being, and economic capacity and growth. Undernutrition in the first 1,000 days of a child’s life can cause irreversible stunting and mental impairment. Poor communities in developing countries bear a disproportionate amount of this burden. Through Feed the Future and the Global Health Initiative, the United States supports country-owned programs to address the root causes of undernutrition and improve the future potential of millions of people. This includes helping countries build the technical capacity to manage nutrition programs over the long term. As part of its commitment to Feed the Future, the U.S. also supports the Scaling Up Nutrition (SUN) movement, which focuses on collaboration, results, harmonized multi-sector approaches, and the critical 1,000 days from pregnancy to a child’s second birthday. The 1,000 Days partnership supports SUN by increasing advocacy and programming within this window of opportunity. Read the Feed the Future nutrition fact sheet for more information.