Genetic defects affecting metabolism appear to underpin the slimming disease anorexia nervosa, new research has shown.
Scientists who scoured the DNA of more than 14,000 individuals homed in on a hotspot containing genetic variations associated with anorexia.
The discovery lends support to the theory that the eating disorder is not simply a psychological illness, and is at least partly driven by a person's genes.
Lead researcher Professor Cynthia Bulik, from the Karolinska Institute in Stockholm, Sweden, said: "We identified one genome-wide significant locus for anorexia nervosa on chromosome 12, in a region previously shown to be associated with Type-1 diabetes and autoimmune disorders.
"We also calculated genetic correlations - the extent to which various traits and disorders are caused by the same genes."
The study, published in the American Journal of Psychiatry, found genetic links between anorexia and schizophrenia, as well as neuroticism - a personality trait marked by negative emotions such as depression, anxiety, anger and guilt.
Strong associations were also seen with a number of metabolic features including body composition and the uptake and storage of glucose, which provides "fuel" for cells.
"This finding encourages us to look more deeply at how metabolic factors increase the risk for anorexia nervosa," said Prof Bulik.
More than 220 scientists and clinicians, including researchers from King's College London, took part in the investigation, the most powerful genetic study of anorexia undertaken to date.
The international team, from the Psychiatric Genetics Consortium Eating Disorders Working Group, compared the genomes, or complete genetic codes, of 3,495 anorexia sufferers and 10,982 unaffected individuals.