Eating disorders (ED) are among the leading causes of disease burden, especially in women.

The overall aim is to explore role of parental social characteristics and family composition in the development of ED in adolescent males and females.

We investigated associations of parental socioeconomic position, family type, number of siblings and half-siblings and history of psychiatric disease in parents with the incidence of eating disorders at age 12–23 years.

The Stockholm Youth Cohort (N=589,114) is a database created by record-linkage for all children and adolescents, 0–17 years, resident in Stockholm County during the period 2001–2007, their parents and siblings. Hazard rations were calculated using Cox regression. Cases of ED were identified in outpatient care.

A total of 3251 cases of ED (2971 females and 280 males) were recorded among 249,884 study subjects. There was an increased risk of ED in both male and female offspring of parents who had a history of alcohol and drug abuse or psychiatric ill-health. Higher parental education was a risk factors in females. Increasing number of full siblings had a protective effect (fully adjusted HR 0.91, 95% CI 0.87–0.96, per sibling) while increasing number of half-siblings appeared to increase risk of eating disorders in females.

Risk factors for ED seem to differ between females and males. While parental psychiatric health is related to risk of ED in both sexes, family socioeconomic position and relationships within family appear to be of more importance for influencing risk of ED in females.