Higher eating frequency is associated with lower adiposity and robust circadian rhythms: a cross-sectional study.

Background: Although overweight and obesity are assumed to arise from an energy imbalance, evidence has shown that the frequency and timing of meals are also potential risk factors for obesity. However, the lack of a consistent approach to define eating patterns relative to internal circadian rhythms limits the extent of these findings.

Objectives: The objective of this study was to investigate the association of the circadian pattern of energy intake with adiposity and with internal circadian rhythms.

Methods: A total of 260 Spanish adults (aged 20-30 y; 78.1% women) were included in a 6-d cross-sectional study. Participants documented sleep and dietary intake within the study period. From these data, we evaluated the chronotype, eating patterns (meal timing, eating duration, and eating frequency), and we obtained the daily profile of energy intake. In addition, we evaluated the circadian pattern of wrist temperature (internal circadian rhythm marker). Circadian patterns of energy intake and wrist temperature were analyzed, and their association among them and with anthropometric variables and diet quality was studied.

Results: The greater fragmentation of the circadian pattern of energy intake was associated with lower BMI (in kg/m2; -10.55; 95% CI: -16.96, -4.13; P = 0.001). In addition, a greater eating frequency (≥5 eating occasions/d) was significantly associated with lower BMI (-1.88; 95% CI: -3.27, -0.48) and higher energy intake after 20:00 (4.14% of kcal; 95% CI: 1.67, 7.16). Furthermore, a greater eating frequency was associated with lower fragmentation (P = 0.042) and greater stability of the circadian pattern of wrist temperature (P = 0.016).

Conclusions: The daily pattern of energy intake is associated with adiposity and robust circadian rhythms. Our results shed light on the relevance of eating frequency as a potential zeitgeber for the circadian system. Although more evidence is needed, eating frequency could be considered for future chrono-nutritional recommendations for the prevention of circadian misalignment and obesity.