Daily pattern of energy distribution and weight loss

Exploring factors influencing late evening eating and barriers and enablers to changing to earlier eating patterns in adults with overweight and obesity

Late evening eating is a potential risk factor for overconsumption and weight gain. However, there is limited qualitative research investigating the complex factors that influence late evening eating in adults living with obesity. Identifying the factors that influence late evening eating can inform interventions to reduce late evening eating and associated health risks. Therefore, this study aimed to: i) explore factors that contribute to eating late, and ii) apply the Capability, Opportunity, and Motivation Behaviour (COM-B) model to understand the barriers and enablers to changing to earlier food intake timings in UK adults who report eating late. Semi-structured interviews with seventeen participants [32.47 ± 6.65 years; 34.68 ± 7.10 kg/m2; 71% female (n = 12); 41% White (n = 7)] investigated reasons for late evening eating and the potential barriers and enablers to changing to earlier eating patterns. Thematic analysis identified four main contributors to late evening eating: 1) internal signals (e.g., feeling hungry in the evening); 2) external and situational factors (e.g., work schedules and the food-rich environment); 3) social factors (e.g., interactions with family) and 4) behavioural and emotional factors (e.g., personal preferences and negative feelings in the evening). Time constraints and work schedules were identified as main barriers to changing to earlier eating patterns. Whereas, having high motivation (e.g., contentment with eating earlier in the evening) and interpersonal support were identified as main enablers to eating earlier. This study provides in-depth insights into the psychological, social, and environmental factors contributing to late evening eating. The findings highlight potential targets for future interventions to facilitate earlier eating times in individuals at risk of overweight and obesity.

Chrononutrition in traditional European medicine-Ideal meal timing for cardiometabolic health promotion

Meal timing plays a crucial role for cardiometabolic health, given the circadian regulation of cardiometabolic function. However, to the best of our knowledge, no concept of meal timing exists in traditional European medicine (TEM). Therefore, in this narrative review, we aim to define the optimal time slot for energy intake and optimal energy distribution throughout the day in a context of TEM and explore further implications. By reviewing literature published between 2002 and 2022, we found that optimal timing for energy intake may be between 06:00 and 09:00, 12:00 and 14:00, and between 15:00 and 18:00, with high energy breakfast, medium energy lunch and low energy dinner and possibly further adjustments according to one's chronotype and genetics. Also, timing and distribution of energy intake may serve as a novel therapeutic strategy to optimize coction, a concept describing digestion and metabolism in TEM. Please cite this article as: Eberli NS, Colas L, Gimalac A. Chrononutrition in traditional European medicine-Ideal meal timing for cardiometabolic health promotion. J Integr Med. 2024; 22(2);115-125.

Alignment between timing of 'highest caloric intake' and chronotype in relation to body composition during adolescence: the DONALD Study

PURPOSE

Our aim was to assess alignment in timing of 'highest caloric intake' with individual chronotype and its association with body composition in adolescents.

METHODS

We used repeatedly collected data from n = 196 adolescents (age 9-16 years, providing N = 401 yearly questionnaires) of the DONALD open cohort study. Chronotype was assessed by the Munich Chronotype Questionnaire from which midpoint of sleep (MSFsc) was derived. A sex- and age-specific diet-chrono-alignment score (DCAS) was calculated as the difference in hours between the chronotype-specific median timing of highest caloric intake of the studied population and the individual timing of 'highest caloric intake' or vice versa. Repeated-measures regression models were applied to study cross-sectional and longitudinal associations between the DCAS and body composition, e.g., Fat Mass Index (FMI) or Fat Free Mass Index (FFMI).

RESULTS

DCAS ranged from -6:42 h to + 8:01 h and was not associated with body composition. Among adolescents with a later chronotype (N = 201) a 1 h increase in DCAS (later consumption of 'highest caloric intake' in comparison to the median intake of that group), increased FFMI by 1.92 kg/m2 (95% CI: 0.15, 3.69, p value = 0.04) over a median follow-up of 0.94 year.

CONCLUSION

Alignment of energy intake with individual chronotype appears beneficial for FFMI among those with a late chronotype.

Circadian misalignment in obesity: The role for time-restricted feeding

BACKGROUND AND AIMS

The epidemic of obesity is associated with a substantial, complex and escalating burden of disease. Dietary and lifestyle interventions provide the mainstay of management; however, obesity is multifactorial and challenging to address clinically. Disrupted circadian behaviours, including late eating, are associated with obesity. Time-restricted feeding (TRF), the confinement of calorie intake to a temporal 'eating window', has received growing interest as a weight-loss intervention. Benefits are purported to arise from the fasting period and strengthened circadian metabolism. However, the current evidence-base for TRF is small-scale, limited, and there has been little evaluation of circadian schedule. This research aims to enable evidence-based conclusions regarding circadian-aligned TRF as a weight-loss intervention in obesity.

METHODS

A systematic three-tranche search strategy was conducted within PubMed. Included studies were critically evaluated. Search tranches scoped: interventional evidence for TRF; evidence linking meal timing, obesity and metabolic function; and evidence linking circadian function, obesity, and dysmetabolism. Results were summarised in a narrative analysis.

RESULTS

A total of 30 studies were included. From small-scale and short-term evidence, TRF was consistently associated with improved weight, glycaemic and anthropometric outcomes versus baseline or control. Good adherence and safety, and consistency of results between studies, were notable. Earlier ('circadian-aligned') eating was associated with greater diet-induced thermogenesis, and improved weight loss and glycaemic outcomes. Limited evidence suggested meaningful correlations between circadian clock function and obesity/metabolic risk.

CONCLUSIONS

Circadian-aligned TRF may present a promising intervention for weight loss and metabolic benefits in obese/overweight individuals.

Associations of timing of food intake with energy intake, eating behaviour traits and psychosocial factors in adults with overweight and obesity

Introduction

Whether a late distribution of food intake impacts obesity through increased energy intake remains uncertain and the behavioural characterization of late eating needs to be further investigated. The first objective of this study was to assess the associations between late eating and body mass index (BMI) and total energy intake (TEI), and whether TEI mediates the association between late eating and BMI. The second objective was to assess the associations between late eating and eating behaviour traits or psychosocial factors and whether eating behaviour traits mediate the association between late eating and TEI.

Methods

Baseline data from 301 individuals (56% women, age = 38.7 ± 8.5 years; BMI = 33.2 ± 3.4 kg/m²), who participated in four weight loss studies were used in this cross-sectional study. Total energy intake was assessed using a three-day food record from which the percentage of TEI after 17:00 and after 20:00 was calculated. Eating behaviour traits and psychosocial factors were assessed with questionnaires. Pearson correlations and mediation analyses adjusted for age, sex, underreporting of energy intake, sleep duration and bedtime were performed.

Results

Percent TEI after 17:00 and after 20:00 were associated with TEI (r = 0.13, p = 0.03 for both), and TEI mediated the association between percent TEI after 17:00 and BMI (β = 0.01 ± 0.01, 95% CI: 0.001, 0.02). Percent TEI after 17:00 was associated with disinhibition (r = 0.13, p = 0.03) and percent TEI after 20:00 was associated with susceptibility to hunger (r = 0.13, p = 0.03), stress (r = 0.24, p = 0.002) and anxiety (r = 0.28, p = 0.0004). In women, disinhibition mediated the association between percent TEI after 17:00 and TEI (β = 3.41 ± 1.43, 95% CI: 0.92, 6.47). Susceptibility to hunger mediated the association between percent TEI after 20:00 and TEI (β = 0.96 ± 0.59, 95% CI: 0.02, 2.34) in men and women.

Conclusion

Late eating is associated with TEI and suboptimal eating behaviours which could contribute to explaining the association between timing of food intake and obesity.

Bidirectional mediation of evening energy proportion and chronotype on their associations with blood lipid levels in a Chinese population

The bidirectional relationship between chronotype and meal energy distribution, and the effect of their relationship on blood lipid level has not been investigated. This study aims to test and compare the bidirectional mediating effects of chronotype and meal energy distribution on blood lipid levels. Data of 9376 adult participants from 2018 wave of the China Health and Nutrition Survey (CHNS) were analysed. Two mediation models were tested and compared: one with Evening energy proportion (Evening EI%) as mediator of the association between adjusted mid-sleep time on free days (MSF_a) and blood lipid levels and the other with MSF_a as mediator of the association of Evening EI% with blood lipid levels. The mediating effect of Evening EI% on the association between MSF_a and TC, LDL-C and non-HDL-C were significant (p < .001, p = .001, and p = .002, respectively). The mediating effect of MSF_a on the association between Evening EI% and TC, LDL-C and non-HDL-C were significant (p = .006, p = .035, and p < .001 respectively). Evening EI% had a larger standardized mediation effect compared to MSF_a. The bidirectional mediation effect suggests a reinforcement mechanism, in which later chronotype and higher Evening EI% reciprocally influence their negative impact on elevated blood lipid levels, leading to higher risk of cardiovascular diseases in the general population.

Eating Patterns of Young Women (18–25 y) with Overweight and Obesity: A Preliminary Investigation

Overweight and obesity impact up to 40% of young women in Australia; however, young women are challenging to recruit to research and are rarely the focus of weight loss interventions. This study aimed to examine dietary patterns in young women (18–25 years; BMI > 25 kg/m2). An analysis of participants’ (mean age: 22.6 year; BMI: 32.2 kg/m2) 3-day food records found young women with overweight/obesity consumed a diet characterised by total energy intake of 9174 (2526) kJ/day, with the first meal at 9:12 am (range: 4:30 am–12:40 pm), the last at 10:43 pm (range: 2:40 pm–2:00 am), and an average eating window of 11.5 h. Young women had poor quality diets, which did not meet dietary recommendations for most core food groups, and high intake of refined carbohydrates. They also reported consuming at least one takeaway meal per day and >30% of total energy intake was from discretionary items. The findings showed that young women with overweight or obesity consume most of their energy intake in the afternoons and late into the evenings and have poor-quality diets with high-discretionary intake, each of which have been shown in previous work to be associated with increased weight and risk of metabolic comorbidities. While these findings require further examination in larger groups with both qualitative and longitudinal data collection to verify the impact of these eating patterns on weight maintenance, the eating behaviours identified here may present a suitable target for novel weight loss interventions in young women, who are an understudied population group in need of tailored weight management solutions.

Distribution of energy intake across the day and weight loss: A systematic review and meta-analysis

Consuming a greater proportion of total energy intake earlier in the day rather than in the evening is proposed to positively influence weight loss and health, potentially due to greater synchronization of human body circadian rhythms. This systematic review provides an update on existing evidence regarding earlier distributed eating patterns in weight loss interventions. Using a robust search strategy in five electronic databases, nine randomized controlled trials investigating the impact of energy intake distribution on weight loss were identified. Following critical appraisal, a random-effects meta-analyses found that, in the context of an energy-reduced diet, distributing energy intake with a focus on earlier intake resulted in significantly greater weight loss (-1.23 kg; 95% CI 2.40, -0.06, p = 0.04). Improvements in HOMA-IR, fasting glucose, and LDL cholesterol were also seen. The current study provides a timely update on the evidence linking distribution of total daily energy intake and health, showing that a focus on earlier intakes can result in greater short-term weight loss compared with later intakes. Future studies are needed to elucidate the impact that earlier intakes may have on weight management and metabolic health.

Breakfast Size and Prevalence of Metabolic Syndrome in the European Prospective Investigation into Cancer and Nutrition (EPIC) Spanish Cohort

BACKGROUND

Recent evidence suggest that energy distribution during the daytimecould be a potential determinant for the development of metabolic syndrome (MetS).

OBJECTIVE

To cross-sectionally assess the association between breakfast size and the prevalence of MetS in Spanish adults.

METHODS

Our study included a subset of 3644 participants from the European Prospective Investigation into Cancer and Nutrition Spain study recontacted between 2017-2018. Information on diet, sociodemographic, lifestyle, sleep quality, and chronotype was collected using standardized questionnaires, while anthropometric and blood pressure data were measured in a face-to-face personal interview by a nurse. MetS was defined according to the Adult Treatment Panel III (ATPIII) definition by measuring serum levels of total cholesterol, tryglycerides and glucose. Breakfast size was calculated as: (energy from breakfast/total energy intake) * 2000 kcal. To evaluate the association between breakfast size and MetS prevalence, a multivariable logistic regression model adjusted by potential confounders was used to estimate OR and 95% CI.

RESULTS

Prevalence of MetS in our study was 40.7%. The mean breakfast size was 306.6 * 2000 kcal (15% of the total daily energy intake), with 14 (0.4%) participants skipping breakfast. Participants in the highest quartile of breakfast size had a lower MetS prevalence compared to participants in the lowest quartile (OR_Q4vsQ1 = 0.62; 95% CI = 0.51-0.76; p-trend < 0.001). No modification of the estimated ORs by sex, breakfast time, and number of eating occasions per day were observed.

CONCLUSION

Our results suggest that higher breakfast size is associated with lower prevalence of MetS in Spanish adults, supporting the importance of a high energy breakfast. Further prospective studies are necessary to confirm these findings.

Snacking among shiftwork nurses related to non-optimal dietary intake

AIMS

To compare nurses' non-optimal eating behaviours across different shifts, to examine whether non-day shifts were related to deviation from optimal dietary behaviours compared with day shifts and whether such deviation was related to non-optimal macronutrient intake.

DESIGN

This is a 4-day intensive longitudinal study.

METHODS

A convenience sample of hospital nurses was recruited in Taiwan. From September 2018 through January 2019, 120 participants completed 4-days of 24-h dietary recalls. One-way ANOVA and Kruskal-Wallis H test were used to compare differences in energy and macronutrient intake and frequency of meals and snacking, respectively. Generalized linear regressions examined (1) the associations between shiftwork schedules and non-optimal eating behaviours and (2) associations between non-optimal eating and high energy contribution of non-optimal macronutrients.

RESULTS

Nurses consumed less energy on evening and night shifts compared with day shifts. However, energy intake from snacking was higher on evening and night shifts relative to day shifts. Nurses consumed less meals but had higher snacking frequency on non-day shifts. In addition, high energy intake from snacking was positively associated with high energy intake from saturated fat.

CONCLUSIONS

Nurses were more likely to have non-optimal eating behaviours on non-day shifts, which may contribute to an increased intake of saturated fat; thus, increasing their risk of chronic diseases. Strategies to improve non-day shift nurses' non-optimal eating behaviours may be beneficial to their health.

IMPACT

Shiftwork is known to affect nurses' eating behaviours; however, which shift is associated with unhealthy eating remains inconclusive. Despite lower energy intakes, nurses had higher intake by snacking on evening and night shifts. High snacking intake was associated with a high intake of saturated fat. Hospitals can increase the availability of healthy foods on evening or night shifts, which may improve non-day shift nurses' non-optimal eating behaviours.

Time-Related Eating Patterns Are Associated with the Total Daily Intake of Calories and Macronutrients in Day and Night Shift Workers

The aim of the study was to investigate whether time-related eating patterns are associated with the daily intake of calories and macronutrients in Brazilian male military police officers (n = 81; 29-day and 52-night workers; mean age: 36.4 ± 0.9 and 38.5 ± 0.7 years, respectively). Energy and macronutrient intake were determined by a non-consecutive 3-day food recall. Time-related eating patterns, such as the time of the first and the last meals, eating duration, and caloric midpoint, were evaluated. Individuals were classified as “early” or “late” eaters according to the median caloric midpoint. Night shift workers showed a later eating time for the last meal (p < 0.001), longer eating duration (p < 0.001), and later caloric midpoint (p = 0.037) than day workers. Late eaters from both workgroups consumed more 24 h energy (p = 0.028), fat in calories (p = 0.006) and protein (calories: p < 0.001; percentage of total calories: p = 0.042), and less carbohydrates in calories (p = 0.010) intake than early eaters. The time of the first meal was negatively correlated with 24 h energy (p = 0.024) and carbohydrate (p = 0.031) intake only in day workers. The time of the last meal was positively correlated with 24 h energy (day workers: β = 0.352; p = 0.044; night workers: β = 0.424; p = 0.002) and protein (day workers: β = 0.451; p = 0.013; night workers: β = 0.536; p < 0.001) intake for both shift workers, and with carbohydrate (β = 0.346; p = 0.016) and fat (β = 0.286; p = 0.042) intake only in night workers. Eating duration was positively correlated with energy (day workers: β = 0.473; p = 0.004; night workers: β = 0.320; p = 0.023) and carbohydrate (day workers: β = 0.418; p = 0.011; night workers: β = 0.364; p = 0.010) intake in both groups. Thus, time-related eating patterns indicative of intake later at night are associated with increased daily energy and macronutrient intake.

Study protocol for the Shifting Weight using Intermittent Fasting in night shift workers (SWIFt) study: a three-arm randomised controlled trial comparing three weight loss strategies in night shift workers with obesity

INTRODUCTION

Shift workers are at an increased risk of developing obesity and type 2 diabetes. Eating and sleeping out of synchronisation with endogenous circadian rhythms causes weight gain, hyperglycaemia and insulin resistance. Interventions that promote weight loss and reduce the metabolic consequences of eating at night are needed for night shift workers. The aim of this study is to examine the effects of three weight loss strategies on weight loss and insulin resistance (HOMA-IR) in night shift workers.

METHODS AND ANALYSIS

A multisite 18-month, three-arm randomised controlled trial comparing three weight loss strategies; continuous energy restriction; and two intermittent fasting strategies whereby participants will fast for 2 days per week (5:2); either during the day (5:2D) or during the night shift (5:2N). Participants will be randomised to a weight loss strategy for 24 weeks (weight loss phase) and followed up 12 months later (maintenance phase). The primary outcomes are weight loss and a change in HOMA-IR. Secondary outcomes include changes in glucose, insulin, blood lipids, body composition, waist circumference, physical activity and quality of life. Assessments will be conducted at baseline, 24 weeks (primary endpoint) and 18 months (12-month follow-up). The intervention will be delivered by research dietitians via a combination of face-to-face and telehealth consultations. Mixed-effect models will be used to identify changes in dependent outcomes (weight and HOMA-IR) with predictor variables of outcomes of group, time and group-time interaction, following an intention-to-treat approach.

ETHICS AND DISSEMINATION

The study protocol was approved by Monash Health Human Research Ethics Committee (RES 19-0000-462A) and registered with Monash University Human Research Ethics Committee. Ethical approval has also been obtained from the University of South Australia (HREC ID: 202379) and Ambulance Victoria Research Committee (R19-037). Results from this trial will be disseminated via conference presentations, peer-reviewed journals and student theses.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN-12619001035112).

Development and Evaluation of Integrated Chrono-Nutrition Weight Reduction Program among Overweight/Obese with Morning and Evening Chronotypes

This paper describes the development of an integrated chrono-nutrition weight reduction program and the evaluation of the attendance, retention, satisfaction and compliance towards the chrono-nutrition components among morning and evening chronotypes for overweight/obese non-shift workers. The present study was conducted in two phases: Phase I was composed of needs assessments on the chronotypes’ dietary patterns and chrono-nutrition through a scoping review and integrating the chrono-nutrition components (temporal eating pattern, meal timing and sleeping habits) alongside the existing weight reduction module, SLIMSHAPE™. Phase II consisted of a feasibility study to evaluate the integrated chrono-nutrition weight reduction program (SLIMSHAPE™ Chrono). A total of 91 overweight/obese non-shift workers participated in the 12-week weight reduction program (Age: 39.6 ± 6.3 years; 74.7% women; BMI: 31.2 ± 4.5 kg/m2). Low attrition rate was recorded, with 85 participants (93.4%) completing the pre- and post-intervention assessments. Overall, morning and evening chronotypes had increased their % energy intake in the early eating window (MT: 64.8 vs. 67.2%, ET: 62.7 vs. 65.6%, Mean difference (MD): 2.8, 95%CI: 0.3, 5.1, p = 0.028) and reduced their intake in the late eating window (MT: 35.2 vs. 32.8%, ET: 37.3 vs. 34.4%, MD: −2.8, 95%CI: −5.1, −0.3, p = 0.028) and earlier midpoint of eating (MT: 14:02 vs. 13:49; ET: 14:27 vs. 14:18, 95%CI: −0.4, −0.02, p = 0.029) and had a reduced night eating syndrome score (MT: 10.0 vs. 8.9; ET: 10.7 vs. 8.9, MD: −1.5, 95%CI: −2.5, −0.5, p = 0.004). There was no significant change in the first (MT: 08:12 vs. 08:04, ET: 08:24 vs. 08:22, MD: −0.1, 95%CI: −0.2, 0.03, p = 0.170) and last mealtime (MT: 19:52 vs. 19:33, ET: 20:29 vs. 20:14, MD: −0.3, 95%CI: −0.6, −0.04, p = 0.081), eating duration (MT: 11.7 vs. 11.5 h, ET: 12.1 vs. 11.9 h, MD: −0.2, 95%CI: −0.6, 0.2, p = 0.251) and the elapse time between sleep onset and last meal (MT: 3.1 vs. 3.5 h, ET: 3.5 vs. 3.2 h, MD: 0.1, 95%CI: −0.3, 0.4, p = 0.678). In terms of sleep, evening chronotypes increased their sleep duration (MD: 0.8 h, 95% CI: 0.4, 1.2, p < 0.001) and reduced social jetlag (MD: 19 min, 95% CI: 1.7, 36.3, p = 0.031) post-intervention compared to morning chronotypes. The integrated chrono-nutrition weight reduction program among morning and evening chronotypes improved the temporal pattern of energy intake, meal timing, night eating syndrome and sleep habits post-intervention. The chrono-nutrition practice could be a potentially modifiable behavior as an adjunct strategy in weight management.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7-10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

An Earlier First Meal Timing Associates with Weight Loss Effectiveness in A 12-Week Weight Loss Support Program

Recent studies have reported that meal timing may play an important role in weight regulation, however it is unknown whether the timing of meals is related to the amount of weight loss. This study aimed to examine the relationship between indices of meal timing and weight loss during weight loss intervention in adults. A 12-week weight loss support program was conducted for 97 adults (age: 47.6 ± 8.3 years, BMI: 25.4 ± 3.7 kg/m²). After the program, body weight decreased by −3.0 ± 2.7%. Only the start of the eating window was positively correlated with the weight change rate in both sexes (men: r = 0.321, p = 0.022; women: r = 0.360, p = 0.014). The participants were divided into two groups based on the start of the eating window as follows: the early group (6:48 ± 0:21 AM) and the late group (8:11 ± 1:05 AM). The weight loss rate in the early group was significantly higher (−3.8 ± 2.7%) than that in the late group (−2.2 ± 2.5%). The present results showed that the start of the early eating window was associated with weight loss and suggested paying attention to meal timing when doing weight loss.

Disruption of the circadian rhythms and its relationship with pediatric obesity

The circadian clock system is an evolutionarily conserved system by which organisms adapt their metabolic activities to environmental inputs, including nutrient availability. The disruption of this system has been pathogenically linked to the disintegration of metabolic homeostasis, leading to the development of metabolic complications, including obesity. Lifestyle factors that disrupt this system have been found to be associated with the development of metabolic disorder, which is most evidenced by the finding that shift workers are at an increased risk of developing various disorders, such as obesity and obesity-related complications. Lifestyle factors that contribute to a misalignment between the internal clock system and environmental rhythms have also been identified in children. A short sleep duration and skipping breakfast are prevalent in children and there is mounting evidence that these factors are associated with an increased risk of pediatric obesity; however, the underlying mechanisms have not yet been elucidated in detail. Our current understanding of the impact of lifestyle factors that cause a misalignment between the internal clock system and environmental rhythms on the development of pediatric obesity is summarized herein, with a discussion of potential mechanistic factors.

Food Myths or Food Facts? Study about Perceptions and Knowledge in a Portuguese Sample

Food myths are nutritional concepts poorly justified or even contradict existing scientific evidence that individuals take as the truth. Knowledge in nutrition is an important tool in tackling misinformation and in the promotion of adequate food choices. This study aimed to investigate the beliefs and perceptions of a sample of the Portuguese population regarding a series of food myths and facts, evaluating, consequently, the level of knowledge and the main sources of information. The research was conducted on a sample of 503 participants, using a questionnaire disclosed online, by email, and social networks, between May and June of 2021. Thirty statements, some true and others false, were analyzed to assess people's perceptions. Based on the respondents' answers, a score was calculated for each statement, allowing to differentiate the correct (positive score) from incorrect (negative score) perceptions. The results showed that most statements obtained positive scores, corresponding to correct perceptions. Moreover, the level of knowledge was measured, being very high for 21.7% of the participants and high for 42.1%. The main sources where the participants acquire nutritional information are scientific journals (43.3%), website of the Portuguese General Health Office (DGS) (31.4%), and technical books (31.0%), which is concordant with the level of trust in these sources. Hence, it was concluded that, despite the levels of nutritional knowledge, there are still several food myths that need to be debunked, through the proper channels, in order to promote healthy, balanced, and adequate eating behaviors.

Exercise heat acclimation causes human responses and safety performance improvements

Heat acclimation (HA) is a widely recognized physiological phenomenon of human body in hot environments. HA has many benefits, such aspreventing hyperthermia responses, and is an efficient way to improve human responses to hyperthermal environments. However, it is not known whether HA is dependent on the environmental conditions. Moreover, its mechanism and effect on the safety performance remain unexplored. In this study, we created a climate chamber to simulate a hyperthermal environment. Thirty healthy males were recruited for this study, who were then trained under the same ambient conditions (temperature of 38 °C and relative humidity (RH) of 40%). The training involved running on treadmills (at 5 km/h) to simulate heavy manual labor, and performing heat stress tests (HST) under six different conditions (32 °C/40% RH, 35 °C/40%, 38 °C/40%, 32 °C/70%, 35 °C/70%, and 38 °C/70%). Their physiological indices (rectal temperature, heart rate, sweat loss and skin temperature) and one psychological index (thermal sensation) were measured. Furthermore, a hazard avoidance test device (HATD) was designed to evaluate the individual safety performance by detecting human errors. The results show that training and environmental conditions have different effects on HA. After HA, the physiological and psychological strain were significantly improved. More importantly, HA also helped improve the participants' awareness of the dangers and required emergency responses to face potential hazards. Overall, a reasonable HA training under proper conditions is helpful to ensure the safety of human beings. More research is needed to study the role of HA on safety performance.

Temporal Dietary Patterns Are Associated with Obesity in US Adults

BACKGROUND

The integration of time with dietary patterns throughout a day, or temporal dietary patterns (TDPs), have been linked with dietary quality but relations to health are unknown.

OBJECTIVE

The association between TDPs and selected health status indicators and obesity, type 2 diabetes (T2D), and metabolic syndrome (MetS) was determined.

METHODS

The first-day 24-h dietary recall from 1627 nonpregnant US adult participants aged 20-65 y from the NHANES 2003-2006 was used to determine timing, amount of energy intake, and sequence of eating occasions (EOs). Modified dynamic time warping (MDTW) and kernel k-means algorithm clustered participants into 4 groups representing distinct TDPs. Multivariate regression models determined associations between TDPs and health status, controlling for potential confounders, and adjusting for the survey design and multiple comparisons (P <0.05/6).

RESULTS

A cluster representing a TDP with evenly spaced, energy balanced EOs reaching ≤1200 kcal between 06:00 to 10:00, 12:00 to 15:00, and 18:00 to 22:00, had statistically significant and clinically meaningful lower mean BMI (P <0.0001), waist circumference (WC) (P <0.0001), and 75% lower odds of obesity compared with 3 other clusters representing patterns with much higher peaks of energy: 1000-2400 kcal between 15:00 and 18:00 (OR: 5.3; 95% CI: 2.8, 10.1), 800-2400 kcal between 11:00 and 15:00 (OR: 4.4; 95% CI: 2.5, 7.9), and 1000-2600 kcal between 18:00 and 23:00 (OR: 6.7; 95% CI: 3.9, 11.6).

CONCLUSIONS

Individuals with a TDP characterized by evenly spaced, energy balanced EOs had significantly lower mean BMI, WC, and odds of obesity compared with the other patterns with higher energy intake peaks at different times throughout the day, providing evidence that incorporating time with other aspects of a dietary pattern may be important to health status.

Capturing diversity and cultural drivers of food choice in eastern India

The EAT-Lancet Commission urgently called for "planetary health diets". The success of encouraging dietary shifts, however, crucially hinges on people, and more specifically on consumers' culture, context, socioeconomic status, food environment, attitudes, perceptions, beliefs, and behavior towards food choice. In India, enhanced food availability and accessibility do not readily lead to improved nutritional status. Thus, developing planetary health diets in India requires an understanding of systemic drivers of food choice. Food is an essential part of Indian culture and deeply rooted to the country's history, traditions, lifestyles, and customs. Yet, the diversity and cultural drivers of food choice are still insufficiently understood. To address this knowledge gap, we use expert elicitation to contextualize the "gastronomic systems research" framework to a target population of low-to middle-income households to capture the diversity and cultural drivers of food choice and its nutritional implications in rice-based diets in two states in eastern India. The experts catalogued 131 unique dishes associated with five differentiated daily dining occasions. The majority of dishes belong to the starch food group. Morning snacks exhibit the lowest nutritional diversity while dinners feature the highest diversity in both states. In West Bengal, dish options tend to be carbohydrate-rich and energy-dense, and a significant number of dishes are fried and oily. The gastronomic system mapped by the experts provides a useful baseline for nutritionists, policymakers, and food system actors as a first step in the design of nutrition intervention strategies to develop planetary health diets in eastern India.

Circadian rhythms and meal timing: impact on energy balance and body weight

Energy metabolism and appetite regulating hormones follow circadian rhythms which, when disrupted, could lead to adverse metabolic consequences. Such circadian misalignment, a mismatch between endogenous circadian rhythms and behavior, is most severely experienced by shift workers, due to nighttime wake, daytime sleep, and eating at night. However, circadian misalignment is not restricted to shift workers; milder shifts in sleep and mealtimes, termed social and eating jetlag, are highly prevalent in the general population. Social and eating jetlag result in later mealtimes, which may promote positive energy balance and weight gain. Earlier meal timing, specific to individual endogenous circadian patterns, could serve to reduce cardiometabolic disease burden and aid in weight loss and interventions should be done to test this.

Is the timing of food intake a potential indicator of low weight loss responders? A secondary analysis of three weight loss studies

Individual variability in weight loss in response to a weight loss intervention is commonly observed. Recently, the timing of food intake has been identified as one possible factor implicated in obesity and weight loss. The objective of this study was to further characterize low weight loss responders by assessing the pre-diet distribution of daily energy and macronutrient intakes. A pooled cohort of men and women (n = 122; aged 39.1 ± 8.2 years; body mass index [BMI] 33.1 ± 3.8 kg/m² ) who participated in a 12 to 15 week energy-restricted intervention (-500 to -700 kcal/d) were included in this study. Participants were categorized into two weight loss groups (ie, low [-1.3 ± 2.3 kg] and high [-6.1 ± 2.1 kg] weight loss). Food intake and distribution of energy and macronutrient intakes were assessed using a 3-day food record at baseline. The daily distribution of energy intake (% of total energy intake) was similar in the two weight loss groups with the exception of the low weight loss group who consumed a slightly lower proportion of their total energy intake before 9:00 am compared with the high weight loss group (12.5% ± 5.8% vs 15.0% ± 6.6%, respectively, P = .03). In the low weight loss group, the percentage of energy intake consumed after 8:00 pm was positively associated with total energy intake (r = 0.27, P = .04). The results of this study suggest that the timing of food intake measured prior to a weight loss intervention does not permit the characterization of low weight loss responders.

Weight loss in conservative treatment of obesity in women is associated with physical activity and circadian phenotype: a longitudinal observational study

Introduction

The study investigates the association between circadian phenotype (CP), its stability (interdaily stability - IS) and physical activity (PA) in a weight loss (WL) programme.

Methods

Seventy-five women in WL conservative treatment (BMI ≥ 25 kg/m2) were measured (for about 3 months in between 2016 and 2018) by actigraphy.

Results

We observed a difference in time of acrophase (p = 0.049), but no difference in IS (p = 0.533) between women who lost and did not lose weight. There was a difference in PA (mesor) between groups of women who lost weight compared to those who gained weight (p = 0.007). There was a relationship between IS and PA parametres mesor: p0.001; and the most active 10 h of a day (M10): p < 0.001 - the more stable were women in their rhythm, the more PA they have. Besides confirming a relationship between PA and WL, we also found a relation between WL and CP based on acrophase. Although no direct relationship was found for the indicators of rhythm stability (IS), they can be considered very important variables because of their close connection to PA – a main factor that contributes to the success of the WL programme.

Discussion

According to the results of the study, screening of the CP and its stability may be beneficial in the creation of an individualized WL plan.

The Impact of Time of Day on Energy Expenditure: Implications for Long-Term Energy Balance

There is evidence to indicate that the central biological clock (i.e., our endogenous circadian system) plays a role in physiological processes in the body that impact energy regulation and metabolism. Cross-sectional data suggest that energy consumption later in the day and during the night is associated with weight gain. These findings have led to speculation that when, as well as what, we eat may be important for maintaining energy balance. Emerging literature suggests that prioritising energy intake to earlier during the day may help with body weight maintenance. Evidence from tightly controlled acute experimental studies indicates a disparity in the body's ability to utilise (expend) energy equally across the day and night. Energy expenditure both at rest (resting metabolic rate) and after eating (thermic effect of food) is typically more efficient earlier during the day. In this review, we discuss the key evidence for a circadian pattern in energy utilisation and balance, which depends on meal timing. Whilst there is limited evidence that simply prioritising energy intake to earlier in the day is an effective strategy for weight loss, we highlight the potential benefits of considering the role of meal timing for improving metabolic health and energy balance. This review demonstrates that to advance our understanding of the contribution of the endogenous circadian system toward energy balance, targeted studies that utilise appropriate methodologies are required that focus on meal timing and frequency.

The Effects of High-Temperature Weather on Human Sleep Quality and Appetite

High-temperature weather appears in high frequency, big strength, and long duration in the summer. It is therefore important to study the effects of high-temperature weather on sleep quality and appetite. Ten healthy college students were selected as subjects. The experiment conditions were divided by the daily maximum temperature into 28 °C, 32 °C, 36 °C, and 38 °C. The objective sleep quality was measured by an intelligent sleep monitoring belt, and the subjective sleep quality was measured by a questionnaire survey. The subjective appetites were assessed by a visual analog scale (VAS), and the objective appetites were assessed by the meal weight and the meal time. For sleep quality, the objective results indicated that the sleep quality at 32 °C was the best, followed by 28 °C, while the sleep quality at 36 °C and 38 °C was the worst. Significant effects were mainly reflected in sleep duration and shallow sleep. The subjective results showed that temperature had significant effects on sleep calmness, difficulty in falling asleep, sleep satisfaction, and sleep adequateness. For appetite, the VAS results indicated that high temperatures mainly led to a reduction of appetite at lunch time. The meal weights of lunch were larger than those of supper except for 28 °C, and the meal time of lunch and supper was longer than that of breakfast. The meal time of lunch was longer than that of supper except for 36 °C. This paper can provide a study method and reference data for the sleep quality and appetite of human in high-temperature weather.

A time to fast

Nutrient composition and caloric intake have traditionally been used to devise optimized diets for various phases of life. Adjustment of meal size and frequency have emerged as powerful tools to ameliorate and postpone the onset of disease and delay aging, whereas periods of fasting, with or without reduced energy intake, can have profound health benefits. The underlying physiological processes involve periodic shifts of metabolic fuel sources, promotion of repair mechanisms, and the optimization of energy utilization for cellular and organismal health. Future research endeavors should be directed to the integration of a balanced nutritious diet with controlled meal size and patterns and periods of fasting to develop better strategies to prevent, postpone, and treat the socioeconomical burden of chronic diseases associated with aging.