In this abstract, the focus is on the role played by ultra-processed foods and antisocial behavior. Evidence is presented with regard to what ultra-processed foods are—relative to both academic definitions as well as the NOVA Food Classification System—basic facts about the typical diet of Americans as well as people around the world, health dangers associated with eating too many ultra-processed foods (including cardiometabolic deaths), and then other deleterious outcomes such as mental illness, cognitive decline, and other neuropsychiatric outcomes including antisocial behavior. A brief review is conducted of animal and human studies showing links between diet and behavior. Finally, the abstract reviews studies showing reductions in violent and antisocial behaviors through nutritional interventions. The talk includes a discussion about possible causes and ends with policy implications or how to reduce consumption of ultra-processed foods.