ABSTRACT
In primates in particular, feeding routines have assumed particular importance, and are regularly used to placate aggressors. In humans, mutual feeding has also evolved as a major mechanism for showing affection or sexual interest. If a child is persistently refusing to eat or eating abnormally such that their intake is insufficient to meet their energy or nutritional requirements, then they may meet the criteria for avoidant/restrictive food intake disorder. The genetic component of obesity is complex, but a particular focus of interest is the hormone leptin which has a central role in the regulation of appetite, neuroendocrine function, and energy homeostasis. The genetic associations with metabolic traits naturally suggest these may play a role in maintaining the symptoms of anorexia nervosa. This is suggestion is strengthened by the emergence of anorexia nervosa being around the time of puberty when huge hormonal and metabolic changes are occurring.
