Hunger and eating are behavioral states that are an integral component of the mammalian behavioral repertoire, yet the mechanisms that determine when and how one will experience hunger or engage in eating have yet to be fully elucidated. Various organ systems and cellular signaling mechanisms are thought to contribute to hunger experience and eating behavior, and these factors are modified by environmental influences (e.g. light, nutritional intake). In humans, and Western societies in particular, unprecedented, species-specific conditions including the prevalence of shift work, artificial light, processed foods, and even cultural mindsets and attitudes regarding hunger and eating affect eating behavior and may contribute to the prevalence of eating disorders and obesity. Considering the health risks posed by obesity, eating disorders, and poor nutritional intake, it is important to identify research questions that will advance scientific and medical understanding of the processes that underlie the motivation of hunger and eating behavior. In this presentation, the known physiological (e.g., glucose metabolism, hormone secretion, brain neurotransmitters), psychological (e.g., meal expectation, food-related attitudes), environmental (e.g., sleep patterns, nutrient intake, drug use), and developmental mechanisms that influence hunger and eating are outlined and discussed to identify where more research is required.