The association between nighttime fasting intervals and depression from early pregnancy to postpartum

Nighttime fasting intervals (NFIs; i.e., the longest period between the last eating episode of the day and the first of the next day) are associated with depressive symptoms in non-pregnant populations. However, this chrono-nutrition indicator has rarely been explored in the perinatal period, when individuals experience dramatic physiological and psychological changes. We explored potential associations between NFIs and depressive symptoms during the perinatal period.

This secondary analysis included 232 individuals with pre- pregnancy body mass index (BMI) ≥25 kg/m². Participants were assessed during early-pregnancy, mid-pregnancy, and at 6-months postpartum. NFIs and breakfast time were estimated from 24-hour dietary recall interviews, and depressive symptoms were self-reported using the Center for Epidemiologic Studies Depression Scale. NFIs were categorized into three classifications to represent short, middle, and long NFIs. Longitudinal associations were evaluated using mixed effects linear models with interaction terms between NFIs and each timepoint.

NFIs remained largely stable at the group level across the three study visits ( M [ SD ] = 12.7 [2.75] hours). Although NFIs were not significantly associated with depressive symptoms, long NFIs showed geometric mean ratio of 0.84 (95% CI: 0.64-1.11) relative to middle NFIs at mid-pregnancy.

NFIs and depression were not associated among this perinatal sample. Future studies should explore circadian eating patterns (e.g., the timing of the last eating episode relative to dim-light melatonin onset), different timepoints (e.g., late pregnancy), and pregnant individuals across the weight spectrum.

Nighttime fasting intervals are associated with depressive symptoms in non-pregnant populations, yet their role during the perinatal period remains unclear. We investigated NFIs and depressive symptoms across early-pregnancy, mid-pregnancy, and 6 months postpartum in women with overweight or obesity. NFIs were largely stable across visits, while depressive symptoms, measured by the Center for Epidemiologic Studies Depression Scale, improved over time.NFIs were not significantly associated with depressive symptoms during the perinatal period overall. However, in mid-pregnancy, shorter fasting intervals were associated with approximately 10 percents higher predicted probability of depression compared to longer intervals, suggesting a potentially clinically meaningful difference that warrants further investigation.After adjusting for sleep quality, longer NFIs were significantly associated with lower depressive symptoms in mid-pregnancy, which highlights sleep quality as an important covariate. Future studies with larger samples and objective measures of chronotype, sleep, and depression are needed to clarify the role of NFIs in perinatal mental health.