Introduction:
Social jet lag, typically defined as the difference in sleep timing on work vs. free days, is related to elevated cardiovascular disease (CVD) risk, via circadian disruption. Irregular meal timing may also lead to circadian disruption, but the role of social jet lag in eating patterns in CVD risk has not been examined.
Hypothesis:
Social jet lag in eating patterns, a measure of meal timing variability, will be associated with elevated cardiometabolic risk in women.
Methods:
Women from the AHA Go Red for Women SFRN at Columbia (n=116, mean age: 33 y, 45% Hispanic) completed a 1-wk food record using the web-based NIH Automated Self-Administered 24-h Dietary Assessment Tool. Social jet lag in eating patterns was evaluated using the difference between weekday vs. weekend: 1) nightly fasting duration (NFD), 2) time of first meal, and 3) time of last meal. Standard deviation (SD) of % kcal consumed after 5PM and 8PM was used to capture variability in nighttime eating. Cardiovascular health (CVH) was assessed with the AHA Life Simple 7 (LS7) score. Linear regression models adjusted for age, socioeconomic status, and sleep were used to examine associations with CVH, BMI, waist circumference (WC), systolic blood pressure (SBP), diastolic BP (DBP), and fasting glucose.
Results:
The average time of first meal and NFD on weekdays vs. weekends was 8:54AM vs. 10:11AM and 12.5 h vs. 13.7 h, respectively; average time of last meal was similar (8:27PM). Each 1-h increase in the difference between first meal time on weekdays vs. weekends was associated with higher BMI (β=0.81, p=0.018), WC (β=0.67, p=0.029), DBP (β=1.34, p=0.049), and SBP (β=1.45, p=0.062). Each 1-h increase in the difference between weekday vs. weekend NFD was associated with higher BMI (β=0.55, p=0.045), fasting glucose (β=2.46, p=0.028), and SBP (β=1.17, p=0.058) and lower LS7 score (β=-0.24, p=0.014). Greater variability in nighttime eating (higher %kcal after 5PM and 8PM SD) was associated with higher WC (β=0.014, p=0.020 and β=0.030, p=0.040).
Conclusions:
Greater meal timing variability was related to poorer CVH and higher BMI, WC, BP, and fasting glucose. Results suggest that stabilizing meal timing patterns should be considered for lowering CVD risk and warrant confirmation in a larger sample.