Neurophysiology and Endocrine Responses to Hunger and Satiety Mechanisms: The Brain-Gut Crosstalk

Background: Obesity is a main public health problem which substantially increases the risk of many diseases. The complex neural circuitry controls energy homeostasis and food consumption by the incorporation of hormonal and neural signals. Circulating hormones, in specific the gut hormones, have been found to be very important in appetite regulation. These hormones transfer energy situation signs to the brain throughout three principle paths: the circulation system, activation of the vagus nerve, and direct modification of main brain regions such as the hypothalamus and brainstem. The control of food eating is not exclusively dependent on the homeostatic processes, rather it includes reward mechanisms in which the brain plays a key role. Highly palatable foods, especially those high in sugar and fat, have clear impacts on brain circuits through activating main reward-related areas such as the nucleus accumbens and prefrontal cortex. Frequent exposure to these stimuli increases neural replies, causing increased ingestion due to the over activation of reward systems, which contributes to weight gain and obesity. Objective: This review aims to give an overview of the relationship between obesity and food eating from a neuroscientific view, and highlight the interaction between the central nervous system and the endocrine system in appetite and energy homeostasis regulation. Also, it investigates how energy-dense foods affect reward paths, contributing to overeating and obesity. Key Findings: The findings indicate that the hypothalamus and reward circuits play a vital role in energy homeostasis. Also, hormonal signs, such as leptin and ghrelin, regulate the feeding behavior, affecting weight regulation. Conclusion: Understanding the neuroendocrine basis of the eating behavior and addiction to highly palatable food is important for improving the non-surgical strategies for therapeutic obesity. Recommendation: Future research should aim to explore targeted interventions that adjust the reward pathways.