Nutrition/Obesity
Energy-Density Dietary Inflammatory Index (EDII) and Sleep Quality, Duration, and Timing within the Mobile Lifestyle Intervention for Food and Exercise (mLIFE) Study Michael Wirth* Michael Wirth Wirth Wirth Wirth University of South Carolina
Background: Previous research has shown that pro-inflammatory changes in diet overtime are associated with worsening sleep characteristics. However, such associations have not been examined within virtually delivered interventions. This study examined whether changes in the Energy-density Dietary Inflammatory Index (E-DII) led to changes in bedtime, wake time, sleep duration, or sleep efficiency in a mobile lifestyle intervention.
Methods: Data derived from the Mobile Lifestyle Intervention for Food and Exercise (mLIFE) study. mLIFE was a 12-month lifestyle intervention via a mobile app with or without a gamification component. Assessments occurred at baseline, month 6 and month 12. Sleep was assessed via Fitbit. Diet was assessed via 3 unannounced 24-hour dietary recalls at each assessment. With adjustment for demographic characteristics, linear mixed models assessed the impact of increases (becoming more pro-inflammatory) in the change in E-DII (ranges from -8 to +8) and baseline E-DII on sleep outcomes. Study arm was also assessed as an effect modifier.
Results: Every one-unit higher baseline E-DII was associated with an 8.1-minute later bedtime (p<0.01) and 6.4-minute later wake time (p=0.02). Change in E-DII was not associated with changes in any sleep measures. An interaction existed between change in E-DII and study arm for sleep duration (p=0.05). Among those without gamification, there was a 3.7-minute increase in sleep duration per increase in E-DII, whereas those with gamification showed a 1.5-minute decrease in duration. Neither of these findings achieved statistical significance.
Conclusions: Previous studies have typically found associations between the change in E-DII scores and sleep quality. Post-hoc analyses revealed little change in E-DII scores (baseline=0.38, month 6 = 0.16, month 12 = 0.03) which may explain the lack of findings. More anti-inflammatory diet changes are likely needed to evince changes in sleep characteristics.