Marilou DP Tromp,1 Anouk AMT Donners,1 Johan Garssen,1,2 Joris C Verster1,31Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands; 2Nutricia Research, Utrecht, the Netherlands; 3Center for Human Psychopharmacology, Swinburne University, Melbourne, VIC, AustraliaObjective: To investigate the relationship between eating disorders, body mass index (BMI), sleep disorders, and daytime functioning.Design: Survey.Setting: The Netherlands.Participants: N=574 Dutch young adults (18–35 years old).Measurements: Participants completed a survey on eating and sleep habits including the Eating Disorder Screen for Primary care (ESP) and SLEEP-50 questionnaire subscales for sleep apnea, insomnia, circadian rhythm disorder (CRD), and daytime functioning. SLEEP-50 outcomes of participants who screened negative (≤2) and positive (>2) on the ESP were compared. In addition, SLEEP-50 scores of groups of participants with different ESP scores (0–4) and different BMI groups (ie, underweight, healthy weight, overweight, and obese) were compared using nonparametric statistics.Results: Almost 12% (n=67) of participants screened positive for having an eating disorder. Relative to participants without eating disorders, participants who screened positive for eating disorders reported significantly higher scores on sleep apnea (3.7 versus 2.9, P=0.012), insomnia (7.7 versus 5.5, P<0.0001), CRD (2.9 versus 2.3, P=0.011), and impairment of daytime functioning (8.8 versus 5.8, P=0.0001). ESP scores were associated with insomnia (r=0.117, P=0.005), sleep apnea (r=0.118, P=0.004), sleep quality (r=−0.104, P=0.012), and daytime functioning (r=0.225, P<0.0001), but not with CRD (r=0.066, P=0.112). BMI correlated significantly with ESP scores (r=0.172, P<0.0001) and scores on sleep apnea (r=0.171, P<0.0001). When controlling for BMI, the partial correlation between ESP and sleep apnea remained significant (r=0.10, P=0.015).Conclusion: Participants who score positive for eating disorders scored significantly higher on sleep disorder scales, and reported significantly more impairment of daytime functioning.Keywords: eating disorders, sleep disorders, insomnia, apnea, circadian rhythm disorder, daytime functioning