The Global Hunger Index tracks progress in reducing hunger at the global and country levels. Calculated every year using data on undernourishment, wasting, stunting, and child mortality, the GHI highlights successes and failures in hunger reduction, and provides insight into the drivers of hunger. The GHI is designed to raise awareness and understanding of regional and country differences in the struggle against hunger and to trigger actions to reduce hunger around the world. The 2017 GHI scores show substantial progress in hunger reduction for the developing world over the long term, although there are disparities at the regional, national, and subnational levels. Africa south of the Sahara and South Asia remain the regions most seriously affected by high levels of hunger.