Inclusion Criteria for AN:  Female sex Age 18-32 3 years BMI < 17.5 kg/m2 Currently fulfilling modified DSM-IV diagnosis of AN with or without amenorrhea, onset age before 25 years Diagnosed less than 2 years ago  For controls:  Female sex Age 18-32 3 years BMI 19 20-25 kg/m2 No lifetime history of obesity (BMI ≥> 30) or eating disorders  Exclusion Criteria:  Any chronic disease or medication that could affect glucose metabolism or neurotransmission History of psychiatric disorders (excl. AN for the corresponding study group) Smoking of tobacco, taking of snuffs, or use of narcotics Abusive use of alcohol