Is time of eating associated with BMI and obesity? A population-based study

Later eating timing in relation to an individual internal clock is associated with lower insulin sensitivity and affected by genetic factors

BACKGROUND

Although the contribution of the circadian clock to metabolic regulation is widely recognized, the role of eating timing in glucose metabolism and diabetes risk remains insufficiently studied. This study aimed (i) to investigate the link between the eating timing pattern relative to individual clock and glucose homoeostasis and (ii) to explore the contribution of genetic and environmental factors to eating timing parameters.

METHODS

In 92 adult twins (NCT01631123), glycaemic traits were assessed using the oral glucose tolerance test. Parameters of eating timing pattern (eating timing itself, daily calorie distribution, and eating frequency) were extracted from five-day food records. Caloric midpoint defined as the time point at which 50% of daily calories are consumed. Circadian timing of eating was determined as a time interval between the clock time of eating and a corrected midpoint of sleep, a chronotype marker. Heritability of eating timing components was estimated by comparing correlations within monozygotic and dizygotic twin pairs and fitting genetic structural equation models.

FINDINGS

Among components of eating timing, the most associations were found for the circadian time of caloric midpoint (CCM). Later CCM was significantly associated with poorer insulin sensitivity, i.e. with lower ISI Stumvoll (β = 0.304, p = 5.9 × 10-4) and higher HOMA-IR (β = -0.258, p = 0.011) indices, as well as with higher fasting insulin levels (β = -0.259, p = 0.013), even after the model adjustment for sex, age, daily energy intake, and sleep duration. Later CCM also demonstrated robust associations with higher BMI and waist circumference. All eating timing components showed high or moderate heritability and were strongly related to individual sleep timing.

INTERPRETATION

Later eating timing in relation to an individual internal clock is associated with lower insulin sensitivity. Shifting the main calorie intake to earlier circadian times may improve glucose metabolism, but genetic factors could influence the feasibility and effectiveness of eating-timing based interventions. The findings should be investigated in a larger cohort.

FUNDING

This work was supported by the German Research Foundation (DFG RA 3340/4-1 to OP-R, project number 530918029), by the European Association for the Study of Diabetes (Morgagni Prize 2020 to OP-R), and by the German Federal Ministry of Education and Research (BMBF NUGAT 0315424 to AFHP). The DZD is funded by the German Federal Ministry for Education and Research (01GI0925).

Chrononutritional Patterns: Examining the Interaction Between Shift Work, Eating Habits and Mealtimes in Shift Workers

PurposeTo analyze the effect of shift work on the total calorie intake, macronutrients and mealtimes of military policemen during working days and off-duty days.DesignQuantitative cross-sectional.SettingMilitary policemen who worked shifts in a city in the Northern region of Brazil.Population34 military policemen aged between 18 and 50.MeasurementsCalorie intake, macronutrients, mealtimes, dietary midpoint and dietary window for working days and off-duty days were analyzed. Generalized Estimation Equations (GEE) with Bonferroni post-test, adjusted for age and BMI test was used to check the differences between the variables.ResultsThe median intake of calories (2781 kcal vs 2350 vs 2295 kcal; P < 0.001), proteins (200 g vs 122.65 g vs 104.24 g; P = 0.006) and lipids (158.41 g vs 86.94 g vs 91.03 g; P = 0.014) was higher when policemen worked day compared night shifts and to off-duty days. Meals started early during the day and the eating window was longer during the day shift, followed by off-duty days and the night shift.ConclusionThese findings reinforce the effect of shift work on eating habits and highlight the need for nutritional strategies adapted to the occupational context of military policemen.

Efficacy of Intragastric Balloon Treatment: Outcomes and Patient Satisfaction 6 Months After Removal

Background and Objectives: This study aimed to investigate the weight loss, changes in eating habits, and satisfaction with the intragastric balloon (IGB) procedure in patients undergoing treatment for obesity, with follow-up until 6 months after IGB removal. Materials and Methods: This study included patients who underwent the IGB procedure between January 2020 and September 2024 at our clinic and were followed-up for 6 months after IGB removal. Patient records were retrieved from the endoscopy database. Parameters before IGB and during IGB removal were obtained from these records. Upon obtaining verbal consent from patients contacted via their registered phone numbers, their self-reported weights 6 months after IGB removal were recorded, and their body mass index (BMI) was calculated. During the same interview, patients were asked about their eating habits before IGB and 6 months after IGB removal, as well as their satisfaction with the procedure, based on questionnaires used in previous studies. The data collected included patients' age, sex, weight, BMI, percentages of weight and BMI loss at IGB removal and 6 months after IGB removal, duration of IGB placement, maximum weight lost during IGB placement, time to achieve maximum weight lost, changes in eating habits, and satisfaction levels. Results: The mean age of the 62 patients who were included in this study was 33.24 ± 8.71 years, with 37 (59.67%) women and 25 (40.32%) men. The mean weight of the patients before IGB was 91.58 ± 7.04 kg, and the mean BMI was 32.00 ± 4.25 kg/m2. The mean duration of IGB placement was 5.83 ± 0.41 months, with a mean maximum weight loss of 14.22 ± 4.70 kg and a mean time to achieve weight loss of 3.91 ± 0.91 months. There was a statistically significant difference between the weight before the IGB and the weight at IGB removal (p < 0.001). A significant difference was also noted in the weight before the IGB and 6 months after IGB removal (p < 0.001). The comparison of satisfaction levels showed no statistically significant difference in eating habits before the IGB (p = 0.384), whereas a significant difference was found in eating habits 6 months after IGB removal (p < 0.001). The weight loss differences between the satisfied and dissatisfied patients were significant at IGB removal and 6 months after, although no statistical difference was found in the pre-IGB weights between the satisfied and dissatisfied patients (p < 0.001). Conclusions: Patients undergoing the IGB procedure for obesity should correct their poor eating habits to maintain successful mid-term weight loss results.

Association of meal time patterns with dietary intake and body mass index: a chrononutrition approach from NHANES 2017-2018

BACKGROUND

Chrononutrition studies suggest that eating later and extending the eating window are linked to higher energy intake and obesity. However, the relationship between chrononutrition variables and dietary intake, as well as with BMI, is still little explored at a population level. This study explored how chrononutrition variables relate to dietary intake and BMI at a population level.

METHODS

We analyzed data from the NHANES 2017-2018, including 2937 participants aged 18 years or older. Dietary intake was assessed by two 24-h dietary recalls. Caloric midpoint, eating window duration, sleep end-first meal and last meal-sleep onset intervals were determined by mealtime.

RESULTS

The findings indicate a trend of increased total consumption of energy (kcal) (p < 0.001; p < 0.001; p < 0.001; p < 0.001), carbohydrates (g) (p = 0.001; p < 0.001; p < 0.001; p < 0.001); protein (g) (p < 0.001; p = 0.008; p < 0.001; p < 0.001), fat (g) (p < 0.001; p = 0.007; p < 0.001; p < 0.001), and sugar (g) (p < 0.001; p < 0.001; p < 0.001; p < 0.001) as the sleep end-first meal interval decreases and the last meal-sleep onset interval, eating window, and energy intake after 8 pm increases, respectively. In addition, our findings suggest a trend of increased BMI in the group with BMI ≥ 30 kg/m² (p = 0.018) as sleep end-first meal interval increases and in the group with BMI < 25 kg/m² (p = 0.006) as the eating window increases.

CONCLUSION

Our findings suggest that eating later and having longer eating window are associated with higher dietary intake and higher BMI.

The relationship between chrononutrition profile, social jet lag and obesity: A cross-sectional study of Chinese college students

This study aimed to investigate the associations between chrononutrition profile, social jet lag (SJL) with obesity-related indicators (body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHTR), and percentage of body fat (PBF)). This cross-sectional study was conducted among college students in a university in Hunan Province, China, from 14 September 2023 to 8 June 2024. This study employed the Chrononutrition Profile - Questionnaire (CP-Q) along with physical examinations. SJL was defined as time difference of midpoint of sleep between the workdays and freedays. Sleep-corrected SJL (SJLsc) is the absolute difference between the sleep onset on free days and workdays. Average evening latency is the time between the last meal of the day and bedtime. Eating jet lag is the difference in the midpoint of the eating window between workdays and freedays. Logistic regression was utilized to assess the associations between chrononutrition profile, SJL, and obesity-related indicators among college students. A total of 805 participants were recruited, of which 695 have complete data after excluding those who did not meet the inclusion criteria. After adjusting for potential covariates, average evening latency <4 h was related with lower risk of high BMI, WC, and PBF [OR (95% CI) = 0.435 (0.285-0.663), 0.508 (0.305-0.848), 0.564 (0.402-0.792), respectively]. Average eating window >12 h was associated with a lower risk of high BMI, WC, and PBF [OR (95% CI) = 0.511 (0.327-0.800), 0.485 (0.277-0.851), 0.651 (0.456-0.930), respectively]. Last eating occasion jet lag >1 h was a higher risk of high PBF [OR (95% CI) = 1.554 (1.018-2.371)]. SJLsc > 1 h was associated with high PBF [OR (95% CI) = 1.527 (1.073-2.174)]. Circadian rhythm disruptions, including SJL and eating jet lag, are prevalent among college students. Long eating window, short evening latency, is associated with low risk of obesity, while short sleep duration, last eating occasion jet lag and larger SJLsc were associated with higher risk of obesity among youths.

Weekday-Weekend Differences in Chrononutritional Variables Depend on Urban or Rural Living

BACKGROUND/OBJECTIVES

Studies have highlighted the impact of work and school schedules on food preferences, suggesting that individuals' dietary choices may change during the week to align with their daily routines. Despite the variation in food composition in the population, there is no evidence identifying differences in food intake times and composition across the days of the week in urban/rural locations. Thus, the study's aim was to identify weekday vs. weekend differences in food intake times and composition (calories) between urban and rural areas.

METHODS

Data from 5770 participants (aged 18-59 years) were analyzed from the National Household Budget Survey (POF-IBGE) consisting of two distinct food diary records (weekday + weekend) per individual, including area (urban or rural) information in Brazil.

RESULTS

During weekdays, the time of the first food intake was significantly earlier, and the last food intake time was significantly later compared to weekends, resulting in a longer eating window on weekdays in both urban and rural areas. People living in urban areas exhibited delayed first and last food intake times, resulting in later caloric and eating midpoints compared to people living in rural areas. Periodogram analysis detected weekly rhythmicity (7 days) at the time of the first food intake and the length of the eating window in urban residents.

CONCLUSIONS

The observed 7-day rhythmic pattern of food intake in urban areas, driven by work and school schedules, underscores the influence of urbanization on dietary timing and composition. In contrast, rural areas exhibited more stable and earlier eating patterns. These results emphasize the need for public health interventions to address meal timing and circadian alignment, particularly in urban settings, to mitigate the risk of metabolic disorders and improve overall health outcomes.

Association of Meal Timing with Sleep Quality and Anxiety According to Chronotype: A Study of University Students

There are several determinants of mental health symptoms, ranging from individual characteristics to social factors. Consistent with patterns in the general population, students with evening characteristics tend to exhibit more anxiety symptoms and poorer sleep quality compared to morning students. Meal timing also appears to affect sleep and may be associated with mental health symptoms. In this context, the aim of the present study was to investigate the association of the timing of the main and last meals of the day with sleep quality and anxiety levels, according to the chronotype of university students. This study was conducted in colleges in São Paulo, Brazil, and involved application of a questionnaire to 162 university students. The questionnaire collected sociodemographic information meal and study times, and included scales assessing eveningness and morningness, sleep quality, and anxiety. Students demonstrating a phase delay in both chronotype and dinner timing exhibited higher levels of anxiety compared to morning-type students. Although no associations were observed between meal timing and sleep quality, sleeping later was associated with poorer sleep quality. The study suggests that evening students and those who eat late at night are more prone to presenting mental health symptoms. More studies are needed to further investigate this association.

Lifestyle, meal times, and sleep patterns changes in higher education professors during COVID-19: Association with non-communicable chronic diseases

BACKGROUND

In response to the COVID-19 pandemic, educational institutions had to swiftly adapt and transition to remote teaching in order to maintain academic activities. However, these changes presented a number of challenges for professors, which could have negative effects on their health.

OBJECTIVE

To analyze the association between changes in dietary and sleep habits, physical activity level, and sedentary behavior with the development of non-communicable diseases (NCDs) among Brazilian higher education professors during the pandemic period.

METHODS

This is a cross-sectional and retrospective study conducted using an online form. Generalized linear models, adjusted for age, sex, and body mass index, were used to verify the difference between pre-pandemic and pandemic periods. Logistic regression models were used to predict the odds ratio (OR) for the development of NCDs according to physical activity time, sedentary behavior time, dietary and sleep patterns.

RESULTS

A total of 936 professors residing across Brazil participated in the survey. The duration of sedentary behavior increased, sleep duration slightly decreased, and meal times shifted to earlier during the pandemic. A total of 22.9%of the participants reported the diagnosis of some NCDs during this period. Physical activity practice was associated with a lower risk of diseases during the pandemic, regardless of the intensity performed. On the other hand, late eating habits and excessive food consumption during the pandemic were associated with a higher risk.

CONCLUSION

The results provide data that can help in the development of public policies that promote health actions to minimize the consequences associated with the pandemic period.