NutriClock: Understanding the association between chronotype and metabolic homeostasis: the circadian clock as a tool for nutritional intervention in obesity

Publications

Assessment of potentially motivating factors to follow time-restricted eating protocols in a population of adults living in Portugal

Publication . Lages, Marlene; Carmo Silva, Sara; Barros, Renata; Guarino, Maria

Chrononutrition is a growing field that has been attracting significant attention for its potential benefits in metabolic health and body weight regulation. Among chrononutrition strategies, time-restricted eating (TRE) is the most extensively investigated approach in clinical studies. TRE intends to synchronise eating and fasting cycles with the human circadian rhythms. However, larger and longer randomised clinical trials are still needed to establish the effectiveness and long-term health outcomes of TRE interventions. Furthermore, it is crucial to explore whether individuals in free-living conditions, outside controlled clinical settings, can successfully adopt TRE principles into their daily routines to achieve potential health benefits. This study aimed to investigate the association between daily routines and potential adherence to TRE protocols, as well as to identify factors that can potentially predict adherence to these protocols in a sample of adults living in Portugal. A cross-sectional study was conducted using an online questionnaire to assess dietary and sleeping habits, daily routines and the likelihood of adherence to various restrictions in daily eating windows. Associations between variables were analysed using the Spearman correlation coefficient and the Chi-Square test, while an ordinal logistic regression was performed to identify predictive factors. Statistical analyses were conducted on IBM SPSS Statistics version 29.0. The questionnaire was filled out by 130 participants (80 % women) with a mean age of 37.9 ± 13.59 years. On workdays, 71.6 % of participants reported a daily eating window of 12 to 14 h, while on free days, the highest percentage (46.6 %) reported between 10 and 12 h. A significant inverse correlation was observed between willingness to adhere to a TRE protocol based on perceived health benefits and both age (ρ = -0.356, p < 0.001) and sex (ρ = -0.321, p < 0.001). Moderate correlations were also found between the willingness to follow a TRE protocol on workdays (ρ = 0.538) and free days (ρ = 0.598) and the potential health benefits of this type of intervention (p < 0.001). Additionally, sex was associated with potential adherence to the TRE protocol (χ²(2) = 10.644, p = 0.005), with a tendency for men to show lower willingness for adherence. Associations were also identified between body weight management and reducing the eating window by 1 to 2 h (χ²(12) = 24.883, df = 12, p = 0.015) and 2 to 3 h (χ²(12) = 22.367, p = 0.034). Moreover, the perceived importance of income, body weight management and cooking knowledge were significant predictors of the likelihood of adherence to a TRE protocol with a 3 to 4 h restriction in the eating window on workdays (p < 0.005). These results provide valuable insights that should be considered when translating research into clinical practice, specifically in an adult population, as individuals’ willingness and motivation to adopt TRE protocols in free-living conditions are influenced by multiple factors.

2025-12Journal article

Open access

Association between dietary intake and the expression of clock genes in adults: a brief report

Publication . Lages, Marlene; Barros, Renata; Ferreira-Marques, Marisa; Correia, Joana; Caseiro, Armando; Guarino, Maria P.; Carmo Silva, Sara; Le Coutre, Johannes

Background: The circadian system regulates several physiological processes, including energy metabolism, through the expression of core clock genes. Animal studies suggest that dietary composition can influence circadian gene expression; however, evidence in humans remains limited. Objective: This study aimed to explore the association between dietary macronutrient intake and the expression of circadian clock genes in the whole blood of adults with distinct metabolic profiles. Methods: Nineteen adults (94.7% female; 43.4 ± 16.05 years) were categorized into healthy-weight and overweight/obesity groups based on BMI. Dietary intake was assessed using a 3-day food diary, and clock gene expression (CLOCK, BMAL1, PER2, CRY) was evaluated in whole blood samples collected between 08:00 a.m. and 04:00 p.m. Statistical analyses included group comparisons and correlation analyses between macronutrient intake and gene expression. Results: No statistically significant differences were observed in the clock gene expression between BMI groups, although group-level trends were noted, particularly in PER2 and CRY expression. The overweight/obesity group exhibited a significantly higher percentage of energy intake from protein. Correlation analyses revealed several time-dependent associations between macronutrient intake and clock gene expression. Notably, in the healthy BMI group, BMAL1 and CRY expression correlated with lipid and protein intake, while in the overweight/obesity group, CLOCK expression was strongly associated with both lipid and carbohydrate intake. Conclusion: These findings suggest that macronutrient composition may influence peripheral circadian gene expression in a time- and BMI-dependent manner. Further research is necessary to confirm these associations in larger and more diverse populations and to investigate the potential for chrononutrition strategies to support metabolic health.

2025-10-08Journal article

Open access