The Night Eating Questionnaire (NEQ; Allison et al, 2008) is the only validated instrument to assess the Night Eating Syndrome. It is composed of 14 Likert items and it enables to rule out for sleep-related eating disorder.

To investigate the psychometric properties of the NEQ and to investigate its pattern of correlation with related variables in a sample of Portuguese overweight women.

The NEQ and the other self-report validated instruments to assess disordered eating, insomnia, daytime sleepiness, depressive symptoms and affect were administered to an outpatient sample of 276 women (Mean age=43.85±11.88; Mean BMI=32.82Kg/m2±5.43) attending a weight loss treatment consultation in a public hospital.

The NEQ Coronach a was .60. A four factors structure (variance explained=57.62%) was selected: Factor (F)1 “Nocturnal ingestions” (α=.81); F2 “Evening hiperfagia” (α=.57); F3 “Mood/Sleep” (α=.42) and F4 “Morning anorexia” (α=.24). From the 23 participants (8.6%) who snacks when get up in the middle of the night, 6 (26.1%) had “not at all/a little” awareness of their eating; 3 (13.0%) had “none at all/a little” control over their eating while up at the night. NEQ total score significantly (p< .01) correlated with disordered eating behaviors (r=.28), insomnia (.50), daytime sleepiness (.27), depressive symptoms (.40), negative affect (.39) and positive affect (-.16).

The Portuguese version of NEQ presents reasonable internal consistency. The factorial structure overlaps with the original almost completely. The pattern of correlations with relevant variables was as expected. The NEQ could be very useful to clinical and epidemiological purposes.