Broiler chickens eat more feed than layer chickens. As a result, broiler chickens grow faster than layer chickens. However, excessive accumulation of body fat in broiler chickens has been a serious problem in the poultry industry in recent decades. Therefore, the appetite regulatory system of chickens has been a focus of research among poultry scientists. Lines of evidence suggest that the physiological role of peripheral adiposity hormones, such as leptin and insulin, and gut hormones, such as ghrelin, are different between mammals and chickens. Thus, species specificity make it difficult to understand the mechanisms underlying the regulation of food intake in chickens. Here I provide an overview of recent findings in this field and future perspectives.