Introduction: Animal studies and limited human research suggest that nightly fasting duration (NFD) and timing of food intake may influence cardiometabolic risk through behavioral and physiological mechanisms. Research is needed to clarify these associations in diverse populations including Hispanic/Latina women, who have elevated cardiometabolic risk.
Hypothesis: We hypothesized that longer NFD would be associated with lower body adiposity, inflammation, blood pressure (BP) and lipids, and glucose regulation indicators and with healthier lifestyle behaviors that may explain associations with cardiometabolic risk.
Methods: We examined associations of NFD with cardiometabolic risk among n= 9,781 diverse Hispanic/Latina women, aged 18-76y, from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), recruited from four US cities between 2008-2011. Pregnant women and those treated for diabetes were excluded. NFD, defined as time from last meal on one day to first meal on the next day, was calculated from two 24-hour recalls. BMI, waist size (WS), BP, blood lipids, glucose, insulin, homeostatic model assessment of insulin resistance, hemoglobin A1c, and C-reactive protein measurements were used in linear and logistic regression models to evaluate associations of NDF with cardiometabolic risk. Models accounted for sample weights and design effects and were adjusted for age, marital status, education, employment, income, health insurance, race, Hispanic/Latino background, acculturation level, BMI, and percent caloric intake consumed after 8PM.
Results: The mean NFD was 12.9±2.3 hours. In linear regression models, longer NFD was associated with higher BMI (β=0.19,p<0.0001), WS (β=0.42,p<0.0001), systolic BP (β=0.20,p=0.012) and lower HDL (β=-0.25,p=0.006). In logistic models, NFD ≥13h vs.<13h was associated with elevated odds of overweight and obesity (OR:1.34,95%CI:1.16-1.54), obesity alone (OR:1.26,95%CI:1.11-1.42), and an “at-risk” WS (OR:1.25,95%CI:1.09-1.43). NFD ≥13h vs.<13h was also associated with higher odds of hypertension (OR:1.20,95%CI:1.02-1.42) and low HDL (OR:1.28,95%CI:1.13-1.46), respectively. When examined in relation to lifestyle, longer NFD was associated with longer self-reported sleep (β=0.05,p<0.0001) and lower caloric intake (β=-37.3,p<0.0001), and null results were observed for diet quality and objectively-measured physical activity.
Conclusions: This large cross-sectional population-based study in U.S. Hispanic/Latina women showed null associations between NFD and glycemic control and inflammation, contrary to previous findings in Caucasian women, but uniquely evaluated and demonstrated deleterious associations between prolonged NFD and other cardiometabolic risk factors. Future studies should investigate longitudinal associations of NFD with cardiometabolic outcomes in this population group.