Association of Nightly Fasting Duration, Meal Timing, and Frequency with Metabolic Syndrome among Iranian Adults.

Accumulative evidence indicates that meal timing is associated with cardiometabolic risks by deteriorating circadian rhythms. However, evidence is unclear. This cross-sectional study aimed to investigate the relation between nightly fasting duration, meal timing and frequency and metabolic syndrome (MetS) among Iranian adults. 850 Iranian adults were recruited in this study. Dietary data were collected by three 24-hours dietary recalls. Time-related eating patterns were determined as nightly fasting duration, occasions of eating, time and energy proportion of first and last meal and meal frequency on a day. MetS was recognized on the basis of the National Cholesterol Education Program Adult Treatment Panel III criteria. A binary logistic regression model adjusted for confounders was applied to examine the relation between meal timing and MetS. A significant inverse relation between habitual nightly fasting duration with MetS (OR = 0.74, 95 % CI 0.55-0.99, P =0.04) and "increased triglyceride (TG)" (OR = 0.73, 95 % CI 0.55-0.98, P =0.03) was found after confounder adjustment. Also, habitual first and last meal energy had no significant connection with MetS. However, the odds of "increased fasting blood glucose (FBG)" were lower in subjects who consumed ≥25% of habitual energy intake in the last meal (OR = 0.60, 95 % CI 0.42-0.85, P =0.005). Having longer nightly fasting duration may be useful for decreasing the risk of both MetS and "elevated TG." These findings introduce a new insight that overall time-related eating patterns, instead of nightly fasting duration alone, might be related to cardiometabolic risks in Iranian adults.