September marked World Water Week. October brought World Food Day. It is fitting that these two events are back to back — they show the key link between water and food and remind us of the need to think systemically about food, water, health, and energy issues. All are related in a complex system. The theme for World Food Day (October 16th) is “Sustainable Food Systems for Food Security and Nutrition” (see FAO link http://www.fao.org/getinvolved/WorldFoodDay/en/ ) — and it is both well-stated and timely. Food security and nutrition are key challenges that require global collaboration now, and they will only grow more pressing as 2050 approaches with two billion more people. The World Food Day site ( http://www.worldfooddayusa.org/learn ) notes some of the key statistics regarding hunger: over 800 million individuals currently face chronic hunger, and two billion lack the necessary micronutrients to ensure good health. Addressing these challenges requires a systems view – with a focus on creating a more sustainable global food system. One key aspect of a sustainable food system involves minimizing waste in a regenerative system that mimics nature. Outputs from one system should become inputs in another. Food waste is a key example. Excess food should be redirected to feed people whenever possible (especially nutrient-dense foods such as fresh produce). Beyond feeding people, excess food can be converted to feed animals, or processed into compost to nourish future food growth. Altering our production systems to eliminate the production of food that eventually goes to waste is another key aspect of making our food system more sustainable. All of these efforts involve making the most of our resources by minimizing waste, and they promote a sustainable food system by reducing damage to the environment in the form of air pollution, water pollution, and soil degradation. All of these areas are ripe for public-private partnerships. We can all start to drive change by taking steps to minimize food waste at the individual level. And then let’s think bigger — and systemically — about partnerships and action to achieve food security and nutrition globally through a sustainable food system. Doing so will ensure that we don’t “waste” the critical theme of World Food Day.