Our internal sensory systems encode various gut-related sensations, such as hunger, feelings of fullness, and nausea. These internal feelings influence our eating behaviors and play a vital role in regulating energy balance. Among them, the neurological basis for nausea has been the least well characterized, which has hindered comprehension of the connection between these sensations. Single-cell sequencing, along with functional mapping, has brought clarity to the neural pathways of nausea involving the brainstem area postrema. In addition, the newly discovered nausea sensory signals have deepened our understanding of the area postrema in regulating feeding behaviors. Nausea has significant clinical implications, especially in developing drugs for weight loss and metabolism. This review summarizes recent research on the neural pathways of nausea, particularly highlighting their contribution to energy balance.