The mediating role of obesity in the associations of meal-specific dietary patterns and chrono-nutrition components with cardiometabolic risk factors: structural equation modeling.

Background: Circadian eating patterns and chrono-nutrition may influence obesity and disease incidence. Thus, this study aimed to assess the mediating role of obesity in the relationship between meal-specific dietary patterns (DPs), chrono-nutritional components, and cardiometabolic risk using structural equation modeling (SEM).

Methods: A cross-sectional study involving 825 Iranian adults was conducted. Dietary intake was recorded using three 24-h dietary recalls. The morning-evening questionnaire was completed. Meal timing, frequency of eating occasions, and irregular energy scores were derived from dietary recalls. Principal component analysis identified DPs for breakfast, lunch, and dinner. Anthropometric measurements, blood pressure, and laboratory investigations, including fasting glucose levels, lipid profiles, and insulin levels, were performed. Insulin resistance was assessed using the homeostatic model, and triglyceride and glucose indices were calculated.

Results: The final SEM showed, that the "oil, egg, and cereals" DPs at breakfast were directly associated with lipids [β (95% CI); 0.105 (0.007-0.203)]. The "oil, dairy, potato, and egg" DPs at lunch were indirectly linked to increased lipids [0.156 (0.040-0.271), BP (0.338 (0.226-0.449)], and insulin indices [0.208 (0.188-0.277)]. At dinner, the "cereal, oil, poultry, and legume" DPs was directly related to lower BP [- 0.095 (- 0.179 to - 0.012)]. The frequency of eating was directly related to lipid levels (- 0.101 (- 0.193 to - 0.008)]. An irregular energy score was not related to outcomes.

Conclusion: More frequent meals and healthier DPs, especially at dinner, were linked to better cardiometabolic outcomes, with obesity mediating some effects. Longitudinal studies are needed to clarify causal relationships.