Correlations between night eating, sleep quality, and excessive daytime sleepiness in a severely obese UK population

The relationships between night eating, poor sleep quality, and obesity-related comorbidity in a severely obese UK clinic population is unknown. We used validated tools to identify prevalence and to explore this relationship.

Consecutive consenting clinic attendees completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Score (ESS), and Night Eating Questionnaire (NEQ) to identify sleep quality, excessive daytime sleepiness (EDS) (a surrogate marker for suspected obstructive sleep apnea [OSA]), and night eating, respectively. Proportions of individuals above and below tool cutoff points were compared. Pearson product moment correlation coefficients examined relationships between total scores.

Reported prevalence from 144 participants (mean body mass index [BMI] 46.9 [9.5] kg/m(2); age 44.6 [12.1]years; 68% women) had poor sleep quality (73.0%), suspected OSA (30.8%), and night-eating behavior (2.8%). The strongest correlation between PSQI and NEQ scores (r=0.54; P<.001) was undiminished after controlling for EDS. Although significantly correlated, PSQI and ESS scores (r=0.31; P<.001) reduced after controlling for night eating (r=0.21; P=.02). Correlation between NEQ and ESS scores (r=0.26; P=.002) was smaller and nonsignificant after controlling for sleep quality (r=0.12; P=.18).

Poor sleep quality is common in severe obesity, though night eating is rare. The association between poor sleep quality and night eating is not influenced by the presence of EDS.