Interindividual differences in energy intake after sleep restriction: The role of personality and implicit attitudes toward food

Sleep restriction (SR) often leads to an increase in energy intake (EI). However, large variability in EI after SR is often observed, which suggests that individual characteristics may affect food intake. The objective of this study was to explore the influence of characteristics generally associated with risk-taking (sensitivity to reward and personality traits: impulsiveness, sensation seeking) and implicit attitudes toward food on EI after sleep loss. 17 subjects completed the NEO-PI-3, an Implicit Association Test measuring implicit attitudes towards healthy and unhealthy foods, and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire. 24h Ad libitum EI was assessed following a habitual sleep night, a 50% SR with an advanced wake time, and a 50% SR with a delayed bedtime. Changes in EI between each SR condition and the control condition (Delta EI) were calculated for each subject. Despite no changes in overall EI between sleep conditions, results showed large interindividual variations (-669 to +899 kcal) across SR conditions. Regression modeling showed that a lower sensation seeking and higher favorable implicit attitudes towards unhealthy food were significantly associated with increased Delta EI in the advanced wake time condition. For the delayed bedtime, lower sensation seeking was associated with increased Delta EI while controlling for age, sex, REM sleep, and implicit attitudes. These results suggest that certain personality traits and implicit attitudes toward food are associated with changes in EI after sleep loss.