0198 THE EFFECTS OF SLEEP RESTRICTION ON FOOD INTAKE: THE IMPORTANCE OF INDIVIDUAL CHARACTERISTICS

Abstract

Acute sleep restriction (SR) often leads to an increase in energy intake (EI). However, large variability in food intake is often observed, which suggests that individual factors may affect EI after SR. The objective of this study was to explore the influence of personality traits (excitement seeking, impulsiveness and sense of competence), implicit attitudes toward food, and sensitivity to reward and punishment on EI after sleep loss. Seventeen subjects (11men; 18-33y) completed a personality inventory (NEO-PI-3), an Implicit Association Test (IAT; this test measures implicit attitudes toward healthy and unhealthy foods), and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ). Ad libitum EI over 24h was assessed following an habitual sleep night and a 50% SR held during the second half of the night. The difference in EI between sleep conditions (∆EI) was calculated for each subject. Correlations between ∆EI and subscales of the NEO-PI-3, IAT score and SPSRQ scores were computed. A multiple linear regression model was performed to examine the unique contribution of each variable that was significantly associated with ∆EI. We controlled for gender, resting energy expenditure and fat% in these analysis. ∆EI was associated with excitement seeking (r=-0.70, p<0.01) and IAT score (r=0.70, p<0.01), suggesting that less excitement seeking and more positive attitudes towards unhealthy food lead to greater EI after SR. Impulsiveness, sense of competence and SPSRQ scores were not associated with ∆EI. Multiple linear regression modeling demonstrated that excitement seeking and implicit attitudes collectively explain 62% of the variance in EI after SR (p<0.001). Excitement seeking was the largest predictor (β=-0.63, p<0.01), followed by implicit attitudes (β=0.40, p<0.05). These results suggest that excitement seeking and implicit attitudes toward food are key factors in explaining variations in EI after sleep loss. Since implicit attitudes are strongly related to educational and personal beliefs/values and personality traits are shaped by early life experiences which tend to remain stable over time, addressing weight gain issues in sleep restriction settings (e.g. rotating shifts) may be more challenging than simply addressing eating behaviors.