Fatty acids are important factors involved in appetite regulation and energy homeostasis， including improving body composition， glucose homeostasis， blood lipid profile， and weight balance. The appetite promoting effect of fatty acids is mediated by a combination of central nervous system and gastrointestinal hormones. On the one hand， fatty acids participate in regulating appetite， feeding behavior， and energy homeostasis through complex neural networks composed of the appetite regulating center (hypothalamus) and other central nervous system regions (including the midbrain marginal dopamine system， striatum， amygdala， etc.). On the other hand， fatty acids transmit gastrointestinal signals to the central nervous system by stimulating the secretion of endocrine hormones such as leptin， insulin， and gastrin， forming the brain gut peptide axis to regulate appetite and feeding behavior. Different chain length fatty acids play different roles in the body， and these effects combine to have an overall impact on the appetite. This article reviews the regulatory mechanisms of fatty acids on appetite through central and peripheral pathways， with a focus on the various appetite regulatory effects and signaling pathways of different chain length fatty acids.