New York, Jan 6: Being an early riser could increase the risk for having anorexia nervosa -- an eating disorder characterised by low weight, food restriction, body image disturbance, fear of gaining weight. The study found that having anorexia nervosa could lead to an earlier wake time. It also revealed a link between anorexia nervosa and insomnia risk. Published in JAMA Network Open, the study showed anorexia nervosa is based on rising early, unlike many other disorders that tend to be evening-based such as depression, binge eating disorder and schizophrenia. Previous research has suggested a possible connection between eating disorders and the body's internal clock, or circadian clock, which controls a wide range of biological functions such as sleep and affects nearly every organ in the body. In the new study, an international team of researchers led by investigators at Massachusetts General Hospital (MGH), found a two-way association between genes associated with anorexia nervosa and genes associated with morning chronotype (waking early and going to bed early). When they further assessed the insomnia connection by developing a 'genetic risk score' for anorexia nervosa, the scientists found that the genetic risk score was indeed associated with higher insomnia risk. 'Our findings implicate anorexia nervosa as a morning disorder in contrast to most other evening-based psychiatric diseases and support the association between anorexia nervosa and insomnia as seen in earlier studies,' said Hassan S Dashti, an assistant investigator in the Department of Anesthesia, Critical Care and Pain Medicine at MGH and an assistant professor of anaesthesia at Harvard Medical School. Treatments for anorexia nervosa are limited and current treatments have relapse rates of up to 52 per cent. In addition, the cause of the disease is still unclear. With anorexia nervosa having the second highest mortality rate of psychiatric diseases, more research is desperately needed into new prevention strategies and treatments. 'The clinical implications of our new findings are currently unclear; however, our results could direct future investigations into circadian-based therapies for anorexia nervosa prevention and treatment,' said lead author Hannah Wilcox, researcher at MGH. /IANS