Poultry production is facing substantial challenges. Among these are the necessity to feed the future in the face of increased human population, and the need to adapt to (global warming and scarce natural resources. As feed costs continue to rise due to severe drought conditions and the diversion of grain to ethanol-biofuel production, it's critical to identify cost-effective and alternative nutritional strategies to improve poultry feed efficiency and sustainability. This chapter aims to offer a review of current understanding on feed intake regulation, highlighting the potential molecular mechanisms by which environmental and nutritional stressors modulate energy intake. The authors begin by outlining the factors influencing feed intake, including flock size and stocking density and lighting. They then discuss the ways in which stress and stressors, such as noise and sounds, and heat and cold stress, can affect flocks. Other stressors described are hypoxia, and nutritional stress and nutrient sensing systems.