New evidence shows that the number of hungry people in the world is growing, reaching more than 820 million in 2018 (one in every nine people), up from 812 million in 2017. There are three main causes of food insecurity: high exposure and vulnerability to climate extremes, conflicts, and economic slowdown. Paradoxically, every year, roughly one third of the food produced in the world for human consumption—approximately 1.3 billion tonnes—is lost or wasted. It is estimated that, if the food lost or wasted globally could be reduced by just one quarter, this would be sufficient to feed the people suffering from chronic hunger in the world. Rice, an important staple food for over half the world’s population, is also affected. At the same time, evidence shows that the food lost or wasted is a major cause of greenhouse gas emission, which itself feeds into climate change and extreme weather, resulting in further food insecurity and malnutrition. This paper briefly introduces the Food and Agriculture Organization of the United Nations (FAO), presents the recent findings on the current situation of food security and nutrition in the world, and highlights the issue of food loss and waste and its impact on food security, with particular emphasis on the constraints it poses to the achievement of key Sustainable Development Goals (SDGs).