An examination of eating misalignment: The discrepancy between preferred and actual timing of food intake

Eating window and eating habits of adults in China: A cross-sectional study

Objective

Previous studies have demonstrated that eating time and habits play key roles in human health. However, there is a paucity of research on the epidemiology of eating window and eating habits in China. This study aimed to investigate the relationship between eating window and eating habits among adults in mainland China and explore the factors influencing these parameters.

Design

Cross-sectional study.

Setting

A questionnaire comprising demographic data, metabolic index, eating window and eating habits was administered via the Internet.

Participants

1596 adults from mainland China.

Results

Eating window of all participants was 13.03 ± 2.02 h (mean ± standard deviation [SD]), which was longer than previously reported in smaller more controlled studies from China. Area of residence and occupation were significant factors influencing eating window after controlling for other factors (area of residence: β, -0.499; 95% confidence interval [CI], -0.897 to -0.101, p = 0.014; occupation: β, -0.309, 95% CI, -0.496 to -0.121, p = 0.001). Participants typically commenced eating at 08:00 h (interquartile range [IQR]: 8:00-9:00) and ceased eating at 20:00 h (IQR: 20:00-22:00). Regular meals which mean two or three meals per day regularly constituted the dominant eating pattern of participants (n = 1233, 77.3%) and 819 (51.1%) participants preferred cooking for themselves.

Conclusion

This study revealed that eating window of adults in China generally around 13 h. Area of residence and occupation were the main factors influencing eating window. Our data provide a foundation for future studies on eating window and eating habits in China.

Weight status of working adults: The effects of eating misalignment, chronotype, and eating jetlag during mandatory confinement

This study aimed to examine the association between chronotype, eating jetlag, and eating misalignment with weight status among Malaysian adults during the COVID-19 restriction. This online cross-sectional study included 175 working adults recruited from March to July 2020. The chronotype was assessed using Morningness Eveningness Questionnaire (MEQ) while eating jetlag and mealtime variability were measured using Chrononutrition Profile Questionnaire (CPQ). Multiple linear regression demonstrated that lower breakfast frequency (β=-0.258, p = .002) and longer eating duration (β = 0.393, p < .001) were associated with later first eating events on workfree days. Both intermediate (β = 0.543, p < .001) and evening chronotypes (β = 0.523, p = .001) tend to eat their first meals later compared to morning person. Similar patterns were observed for overall eating jetlaggers in which lower breakfast frequency (β=-0.022, p = .011), longer eating duration (β = 0.293, p < .001), intermediate chronotype (β = 0.512, p < .001), and evening chronotype (β = 0.495, p = .003) were associated with eating later meals on workfree days. Additionally, higher BMI was also associated with eating later meals on workfree days (β = 0.181, p = .025). During movement restriction, discrepancies of mealtimes during work and workfree days offer new insight into modern eating habits that can influence weight status and general eating habits such as breakfast skipping and total daily eating duration. Population meal timing variability was affected during movement restrictions, and it was closely related to weight status.

Translation, adaptation and validation of the Chrononutrition Profile - Questionnaire (CP-Q) in Brazilian Portuguese

Chrononutrition is a science that studies the relationship between mealtimes and sleep/wake habits. However, these behaviors are not evaluated by a single questionnaire. Therefore, this study aimed to translate and culturally adapt the Chrononutrition Profile - Questionnaire (CP-Q) into Portuguese and validate the Brazilian version. The translation and cultural adaptation process consisted of: translation; synthesis of translations; backtranslation; expert committee and pre-test. The validation was performed with 635 participants (32.4 ± 11.2 years) who answered the CPQ-Brazil and Pittsburgh Sleep Quality Index (PSQI); Munich Chronotype Questionnaire (MCTQ); Night Eating questionnaire; Quality of life and health index (SF-36) and 24 h-recall. The participants were mostly female, single, from the northeastern region, a eutrophic profile, and average quality of life score of 55.8 ± 17.9. Moderate to strong correlations were observed in the sleep/wake schedules between CPQ-Brazil, PSQI and MCTQ, both for work/study days and free days. The correlations between largest meal, skipping breakfast, eating window, nocturnal latency, and last eating event with the same variables in the 24 h-recall showed moderate to strong positive correlations. The translation, adaptation, validation and reproducibility of the CP-Q generates a valid and reliable questionnaire to assess the sleep/wake and eating habits in the Brazilian population.

Associations of chronotype and social jetlag with eating jetlag and their changes among German students during the first COVID-19 lockdown. The Chronotype and Nutrition study

Due to their biologically later chronotype, young students are vulnerable to a discrepant sleeping pattern between work- and free days, coined social jetlag (SJL). This study examined whether a later chronotype and/or a larger SJL are related to an analogous discrepancy in meal timing defined as eating jetlag (EJL) and whether chronotype and/or changes in SJL during the first COVID-19 related lockdown in Germany associated with changes in EJL. Baseline data were collected from September 2019-January 2020 among 317 students (58% females) aged 18-25 years of which a total of 156 students (67% females) completed an online follow-up survey in June-July 2020 (1st lockdown). Data were collected on daily routines, timing of meals/snacks, and physical activity. Chronotype was determined using the Munich ChronoType Questionnaire; SJL and EJL correspond to the difference in the daily midpoint of sleep/eating duration between work- and free days. Multivariable linear regression revealed that students with a later chronotype or a larger SJL experienced a larger EJL (p_adjusted = 0.0124 and p_adjusted<0.0001). A later chronotype at baseline and reductions in SJL during lockdown associated with concurrent reductions in EJL (p_adjusted = 0.027 and p_adjusted<0.0001). In conclusion, students with a later chronotype exhibit a more erratic meal pattern, which associates with SJL. During lockdown, flexible daily schedules allowed students to align the meal timing with their inner clock.

Evaluation of the Chrononutrition Profile - Questionnaire in an online community sample of adults

Chrononutrition (i.e., circadian timing of food intake) has been linked to indicators of health status such as body weight and insulin resistance. A measure of general chrononutrition patterns, the Chrononutrition Profile - Questionnaire, has been developed and preliminary evidence of validity and reliability of the measure has been documented in a homogenous group of undergraduates. However, this measure has not yet been validated in an online, community-based sample. The present study therefore aimed to evaluate the validity of the Chrononutrition Profile - Questionnaire in a web-based community sample. Analyses suggested that the Chrononutrition Profile - Questionnaire displays acceptable validity for use in diverse community samples of adults, with moderate to strong correlations (r = 0.39-0.91) between the Chrononutrition Profile - Questionnaire and measures of dietary intake and sleep. This measure is suitable for use in a variety of settings, by stakeholders and scientists, and may contribute to future development of health behavior interventions and research programs centered around chrononutrition.

Late chronotypes, late mealtimes. Chrononutrition and sleep habits during the COVID-19 lockdown in Italy

The emerging field of chrononutrition provides useful information on how we manage food intake across the day. The COVID-19 emergency, and the corresponding restrictive measures, produced an unprecedented change in individual daily rhythms, possibly including the distribution of mealtimes. Designed as a cross-sectional study based on an online survey, this study aims to assess the chrononutrition profiles (Chrononutrition Profile Questionnaire, CP-Q) in a sample of 1298 Italian participants, during the first COVID-19 lockdown, and to explore the relationship with chronotype (reduced Morningness-Eveningness Questionnaire, rMEQ), sleep quality (Pittsburgh Sleep Quality Index, PSQI) and socio-demographics. Our findings confirm a change in eating habits for 58% of participants, in terms of mealtimes or content of meals. Being an evening chronotype and experiencing poor sleep imply a higher likelihood of changing eating habits, including a delay in the timing of meals. Also, under these unprecedented circumstances, we report that the timing of breakfast is a valuable proxy capable of estimating the chronotype. From a public health perspective, the adoption of this straightforward and low-cost proxy of chronotype might help in the early detection of vulnerable subgroups in the general population, eventually useful during prolonged stressful conditions, as the one caused by COVID-19 pandemic.

Circadian Synchrony: Sleep, Nutrition, and Physical Activity

The circadian clock in mammals regulates the sleep/wake cycle and many associated behavioral and physiological processes. The cellular clock mechanism involves a transcriptional negative feedback loop that gives rise to circadian rhythms in gene expression with an approximately 24-h periodicity. To maintain system robustness, clocks throughout the body must be synchronized and their functions coordinated. In mammals, the master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN is entrained to the light/dark cycle through photic signal transduction and subsequent induction of core clock gene expression. The SCN in turn relays the time-of-day information to clocks in peripheral tissues. While the SCN is highly responsive to photic cues, peripheral clocks are more sensitive to non-photic resetting cues such as nutrients, body temperature, and neuroendocrine hormones. For example, feeding/fasting and physical activity can entrain peripheral clocks through signaling pathways and subsequent regulation of core clock genes and proteins. As such, timing of food intake and physical activity matters. In an ideal world, the sleep/wake and feeding/fasting cycles are synchronized to the light/dark cycle. However, asynchronous environmental cues, such as those experienced by shift workers and frequent travelers, often lead to misalignment between the master and peripheral clocks. Emerging evidence suggests that the resulting circadian disruption is associated with various diseases and chronic conditions that cause further circadian desynchrony and accelerate disease progression. In this review, we discuss how sleep, nutrition, and physical activity synchronize circadian clocks and how chronomedicine may offer novel strategies for disease intervention.