The World Hunger Series (WHS) focuses on practical strategies to achieve an end to hunger. This first issue examines impact of the two-way relationship between hunger and Learning. Hunger impairs learning at each stage of life; yet learning is an effective means of addressing hunger. A vicious cycle can be created: hungry children become damaged adults with limited opportunities and capacities, who end up having hungry children of their own. Such a cycle undermines human and economic development. But this cycle can also be reversed, with good nutrition and enhanced learning reinforcing each other through the generations and leading to long-term national development. Understanding the relationship between hunger and learning requires a long-term perspective: what happens at one stage of life affects later stages, and what happens in one generation affects the next.