Irregular meal-pattern effects on energy expenditure, metabolism, and appetite regulation: a randomized controlled trial in healthy normal-weight women

Exploring the associations between chronotype, meal frequency, and physical activity: A population-based study in adults

Chronotype is an established concept designed to capture the internal clock's phase in real-life conditions. It is vital in many aspects of daily life and can interfere considerably with numerous factors in a given population. Recognizing nonmodifiable and modifiable factors is crucial for identifying covariates of interest when studying the link between chronotype and health status. To date, chronotype and its related factors have not been extensively investigated. The present study aimed to explore the association of chronotypes with meal frequency, physical activity, and demographic factors among the Saudi population. This cross-sectional web-based questionnaire involved 1369 adults (aged 18 years and above) from the general public in Saudi Arabia and was conducted between March and May 2019. Chronotype was assessed using the reduced version of the original Horne and Ostberg morningness-eveningness questionnaire (MEQ). Meal frequencies and demographics data (age, gender, marital status, place of residence, educational level, employment status, income) were obtained. Physical activity level was also obtained using the international physical activity questionnaire. The MEQ scores group individuals into three categories: morning-type, neither-type, and evening-type. The neither-type individuals represented 41.6% (95% confidence interval [CI], 37.5% - 45.6%) of the study population, followed by the morning-type (34.1%; 95% [CI], 29.8% - 38.4%), then the evening-type (24.3%, 95% [CI], 19.6% - 28.9%). Chronotype was significantly associated with age, marital status, employment status and monthly income (All p < 0.05). Significant associations between chronotype with meal frequencies (number of meals per day, breakfast frequency, lunch frequency, and dinner frequency) and physical activity were also observed (All p < 0.05). This study highlights that meal frequencies and physical activity levels are associated with chronotype distribution. Furthermore, demographics, including age, marital status, employment status, and income, were associated with chronotype distribution.

No Effect of High Eating Frequency Compared with Low Eating Frequency on Appetite and Inflammation Biomarkers: Results from a Randomized Crossover Clinical Trial

BACKGROUND

Eating frequency (EF) focuses on the total number of eating occasions per day and may influence metabolic health.

OBJECTIVES

We sought to examine the effect of high compared with low EF on appetite regulation and inflammatory biomarkers among healthy adults.

METHODS

Data are from a randomized, crossover trial (the Frequency of Eating and Satiety Hormones study). Participants (n = 50) completed 2 isocaloric 21-d study periods of low EF (3 eating occasions/d) and high EF (6 eating occasions/d) in random order with a 14-d washout period in between. Participants were free-living and consumed their own food, using study-directed, structured meal plans with identical foods and total energy in both study periods. On days 1 and 21 of each EF period, fasting blood was collected during in-person clinic visits to assess plasma concentrations of ghrelin, leptin, adiponectin, and high-sensitivity C-reactive protein (hs-CRP). Linear mixed models with EF, diet sequence, and period as fixed effects and participant as random effect were used to estimate the intervention effect. Interaction effects between EF and body fat percentage were examined.

RESULTS

Among the 50 participants who completed the trial, 39 (78%) were women, 30 (60%) were Non-Hispanic White, and 40 (80%) had a body mass index of <25 kg/m2, and the mean age was 32.1 y. The differences between high and low EF in fasting ghrelin (geometric mean difference: 17.76 ng/mL; P = 0.60), leptin (geometric mean difference: 2.09 ng/mL; P = 0.14), adiponectin (geometric mean difference: 381.7 ng/mL; P = 0.32), and hs-CRP (geometric mean difference: -0.018 mg/dL; P = 0.08) were not statistically significant. No significant interaction was observed between EF and body fat percentage on appetite regulation and inflammatory biomarkers.

CONCLUSIONS

No differences was observed in fasting ghrelin, leptin, adiponectin, and hs-CRP comparing high and low EF. Future studies are needed to understand the physiology of EF and appetite as they relate to metabolic health. This trial was registered at clinicaltrials.gov as NCT02392897.

A psychobioecological model to understand the income-food insecurity-obesity relationship

Food insecurity, defined by unpredictable access to food that may not meet a person's nutritional needs, is associated with higher BMI (kg/m2) and obesity. People with food insecurity often have less access to food, miss meals and go hungry, which can lead to psychological and metabolic changes that favor energy conservation and weight gain. We describe a conceptual model that includes psychological (food reinforcement and delay discounting) and physiological (thermic effect of food and substrate oxidation) factors to understand how resource scarcity associated with food insecurity evolves into the food insecurity-obesity paradox. We present both animal and human translational research to describe how behavioral and metabolic adaptations to resource scarcity based on behavioral ecology theory may occur for people with food insecurity. We conclude with ideas for interventions to prevent or modify the behaviors and underlying physiology that characterize the income-food insecurity-obesity relationship.

A systematic review of associations between day-to-day variability in meal pattern and body weight, components of the metabolic syndrome and cognitive function

BACKGROUND

Meal pattern is a potential health determinant. Previously, mean values for properties of meal pattern, such as daily meal frequency, have been considered. Means, however, obscure variability between-day (irregular or chaotic eating). This systematic review aimed to identify and critique published methods used to characterise between-day variability in meal pattern, and to explore relationships between this and obesity, as well as associated health outcomes.

METHODS

Using relevant databases, a systematic search was undertaken for studies with adults and children in which between-day variability in meal pattern was measured, and related to body weight, metabolic syndrome components and cognitive function.

RESULTS

In 34 papers identified (28 observational and six intervention studies), between-day variability in meal pattern was characterised by a variety of methods. These ranged from single questions about intake regularity to more complex methods quantifying the degree of variability. Assumptions were made, such as there being three main meals, resulting in dissociation from the "clock time" of eating. In 24 of the papers, between-day variability in meal pattern was associated with negative weight and health outcomes including higher weight, reduced thermogenic response to meals and poorer academic achievement.

CONCLUSIONS

Between-day variability in meal pattern is a promising research area that might inform low-cost public health interventions. However, current methods of characterising between-day variability tend to make assumptions and be inconsistent in the meal pattern properties considered. Well controlled dietary intervention studies are required to confirm causation.

The cerebellum plays more than one role in the dysregulation of appetite: Review of structural evidence from typical and eating disorder populations

OBJECTIVE

Dysregulated appetite control is characteristic of anorexia nervosa (AN), bulimia nervosa (BN), and obesity (OB). Studies using a broad range of methods suggest the cerebellum plays an important role in aspects of weight and appetite control, and is implicated in both AN and OB by reports of aberrant gray matter volume (GMV) compared to nonclinical populations. As functions of the cerebellum are anatomically segregated, specific localization of aberrant anatomy may indicate the mechanisms of its relationship with weight and appetite in different states. We sought to determine if there were consistencies in regions of cerebellar GMV changes in AN/BN and OB, as well as across normative (NOR) variation.

METHOD

Systematic review and meta-analysis using GingerALE.

RESULTS

Twenty-six publications were identified as either case-control studies (nOB  = 277; nAN/BN  = 510) or regressed weight from NOR data against brain volume (total n = 3830). AN/BN and OB analyses both showed consistently decreased GMV within Crus I and Lobule VI, but volume reduction was bilateral for AN/BN and unilateral for OB. Analysis of the NOR data set identified a cluster in right posterior lobe that overlapped with AN/BN cerebellar reduction. Sensitivity analyses indicated robust repeatability for NOR and AN/BN cohorts, but found OB-specific heterogeneity.

DISCUSSION

Findings suggest that more than one area of the cerebellum is involved in control of eating behavior and may be differentially affected in normal variation and pathological conditions. Specifically, we hypothesize an association with sensorimotor and emotional learning via Lobule VI in AN/BN, and executive function via Crus I in OB.

Chrononutrition and metabolic health in children and adolescents: a systematic review and meta-analysis

CONTEXT

Obesity has emerged as a global health issue for the pediatric population, increasing the need to investigate physiopathological aspects to prevent the appearance of its cardiometabolic complications. Chrononutrition is a field of research in nutritional sciences that investigates the health impact of 3 different dimensions of feeding behavior: regularity of meals, frequency, and timing of food intake.

OBJECTIVE

We carried out a systematic review and meta-analysis to investigate the association between chrononutrition in children and adolescents and the risk of overweight/obesity or a cluster of metabolic abnormalities related to glucose and lipid metabolism, blood pressure, and cardiovascular disease risk.

DATA EXTRACTION

A literature search was performed using PubMed, EMBASE, and The Cochrane Library for relevant articles published before August 2022.

DATA ANALYSIS

A total of 64 articles were included in the narrative synthesis (47 cross-sectional and 17 cohort studies), while 16 studies were included in the meta-analysis. Meta-analysis showed that non-daily breakfast consumers (≤6 d/wk) had a higher risk of overweight/obesity (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.08-1.82] compared with daily breakfast eaters (7 d/wk). Similarly, irregular breakfast consumption (only 0-to-3 times/wk) increased the risk of abdominal obesity (waist-to-height ratio ≥ 0.5) compared with regular consumption (5-to-7 times/wk) (OR, 1.38; 95% CI, 1.26-1.49). There was evidence to suggest that a regular frequency of meal consumption (≥4 times/d) is preventive against overweight/obesity development compared with fewer meals (≤3 times/d) (OR, 0.83; 95% CI, 0.70-0.97). In the narrative synthesis, snacking habits showed controversial results, while food timing was the most understudied dimension.

CONCLUSION

Overall, our data indicate a potential implication of chrononutrition in affecting pediatric metabolic health; however, the evidence of this association is limited and heterogeneous. Further prospective and intervention studies with a consistent approach to categorize the exposure are needed to elucidate the importance of chrononutrition for pediatric metabolic health.

A comparative, randomised MRI study of the physiological and appetitive responses to gelling (alginate) and non-gelling nasogastric tube feeds in healthy men

Inclusion in nasogastric tube feeds (NGTF) of acid-sensitive, seaweed-derived alginate, expected to form a reversible gel in the stomach, may create a more normal intragastric state and modified gastrointestinal responses. This may ameliorate NGTF-associated risk of diarrhoea, upper gastrointestinal symptoms and appetite suppression. In a randomised, crossover, comparison study, undertaken in twelve healthy males, an alginate-containing feed (F + ALG) or one that was alginate-free (F-ALG) (300 ml) was given over 1 h with a 7-14-d washout period between treatments. Baseline and for 4-h post-feed initiation, MRI measurements were made to establish small bowel water content (SBWC), gastric contents volume (GCV) and appearance, and superior mesenteric artery blood flux. Blood glucose and gut peptides were measured. Subjective appetite and upper gastrointestinal symptoms scores were obtained. Ad libitum pasta consumption 3-h post-feeding was measured. F + ALG exhibited a gastric appearance consistent with gelling surrounded by a freely mobile water halo. Significant main effects of feed were seen for SBWC (P = 0·03) and peptide YY (PYY) (P = 0·004) which were attributed to generally higher values for SBWC with F + ALG (max difference between adjusted means 72 ml at 210 min) and generally lower values for PYY with F + ALG. GCV showed a faster reduction with F + ALG, less between-participant variation and a feed-by-time interaction (P = 0·04). Feed-by-time interactions were also seen with glucagon-like-peptide 1 (GLP-1) (P = 0·02) and glucose-dependent insulinotropic polypeptide (GIP) (P = 0·002), both showing a blunted response with F + ALG. Apparent intragastric gelling with F + ALG and subsequent differences in gastrointestinal and endocrine responses have been demonstrated between an alginate-containing and alginate-free feed.

Food insecurity as a cause of adiposity: evolutionary and mechanistic hypotheses

Food insecurity (FI) is associated with obesity among women in high-income countries. This seemingly paradoxical association can be explained by the insurance hypothesis, which states that humans possess evolved mechanisms that increase fat storage to buffer against energy shortfall when access to food is unpredictable. The evolutionary logic underlying the insurance hypothesis is well established and experiments on animals confirm that exposure to unpredictable food causes weight gain, but the mechanisms involved are less clear. Drawing on data from humans and other vertebrates, we review a suite of behavioural and physiological mechanisms that could increase fat storage under FI. FI causes short-term hyperphagia, but evidence that it is associated with increased total energy intake is lacking. Experiments on animals suggest that unpredictable food causes increases in retained metabolizable energy and reductions in energy expenditure sufficient to fuel weight gain in the absence of increased food intake. Reducing energy expenditure by diverting energy from somatic maintenance into fat stores should improve short-term survival under FI, but the trade-offs potentially include increased disease risk and accelerated ageing. We conclude that exposure to FI plausibly causes increased adiposity, poor health and shorter lifespan. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Meal Skipping and Shorter Meal Intervals Are Associated with Increased Risk of All-Cause and Cardiovascular Disease Mortality among US Adults

BACKGROUND

Previous dietary studies and current dietary guidelines have mainly focused on dietary intake and food patterns. Little is known about the association between eating behaviors such as meal frequency, skipping and intervals, and mortality.

OBJECTIVE

The objective was to examine the associations of meal frequency, skipping, and intervals with all-cause and cardiovascular disease (CVD) mortality.

DESIGN

This was a prospective study.

PARTICIPANTS/SETTING

A total of 24,011 adults (aged ≥40 years) who participated in the National Health and Nutrition Examination Survey 1999-2014 were included in this study. Eating behaviors were assessed using 24-hour recall. Death and underlying causes of death were ascertained by linkage to death records through December 31, 2015.

MAIN OUTCOME MEASURES

The outcomes were all-cause and CVD mortality.

STATISTICAL ANALYSES PERFORMED

Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) of all-cause and CVD mortality.

RESULTS

During 185,398 person-years of follow-up period, 4,175 deaths occurred, including 878 cardiovascular deaths. Most participants ate three meals per day. Compared with participants eating three meals per day, the multivariable-adjusted HRs for participants eating one meal per day were 1.30 (95% CI 1.03 to 1.64) for all-cause mortality, and 1.83 (95% CI 1.26 to 2.65) for CVD mortality. Participants who skipped breakfast have multivariable-adjusted HRs 1.40 (95% CI 1.09 to 1.78) for CVD mortality compared with those who did not. The multivariable-adjusted HRs for all-cause mortality were 1.12 (95% CI 1.01 to 1.24) for skipping lunch and 1.16 (95% CI 1.02 to 1.32) for skipping dinner compared with those who did not. Among participants eating three meals per day, the multivariable-adjusted HR for participants with an average interval of ≤4.5 hours in two adjacent meals was 1.17 (95% CI 1.04 to 1.32) for all-cause mortality, comparing with those having a meal interval of 4.6 to 5.5 hours.

CONCLUSIONS

In this large, prospective study of US adults aged 40 years or older, eating one meal per day was associated with an increased risk of all-cause and CVD mortality. Skipping breakfast was associated with increased risk of CVD mortality, whereas skipping lunch or dinner was associated with increased risk of all-cause mortality. Among participant with three meals per day, a meal interval of ≤4.5 hours in two adjacent meals was associated with higher all-cause mortality.

Circadian clock and temporal meal pattern

The central circadian clock in the brain controls the time-of-the-day variations in acute meal responses, with a low glycemic response but a high satiety/thermogenic response to meals consumed at waking compared to other time points. Consistently, studies show that consuming a significant proportion of calories, particularly carbohydrates, in breakfast is beneficial for the chronic management of obesity and its associated metabolic syndrome, compared to consuming identical meals at dinner. Conversely, breakfast skipping or/and late dinner can have unfavorable metabolic outcomes. It remains controversial how meal frequency affects metabolic health. In contrast, irregular meals, especially irregular breakfasts, show consistent adverse metabolic consequences. Time-restricted feeding (TRF), with all calories consumed within less than 12-h per day, can improve metabolism and extend lifespan. A major component of TRF in humans is caloric restriction, which contributes significantly to the beneficial effects of TRF in humans. By comparison, TRF effects in rodents can be independent of caloric restriction and show day/night phase specificity. TRF could alleviate metabolic abnormalities due to circadian disruption, but its effects appear independent of the circadian clock in rodents. Understanding neuroendocrine mechanisms underlying clock-mediated metabolic regulation will shed light on the metabolic effects of temporal meal patterns.

Effects of Differences of Breakfast Styles, Such as Japanese and Western Breakfasts, on Eating Habits

A balanced diet and protein source intake are reportedly good for health. However, many people skip breakfast or have a light breakfast. Thus, this study aimed to examine the influence of breakfast styles on eating habits among Japanese workers, including traditional Japanese-style breakfast (JB), a pattern in which Japanese foods are eaten; Japanese-Western-style breakfast (J-W B), a pattern in which Japanese and Western foods are eaten alternately; Western-style breakfast (WB), a pattern in which Western foods are eaten; and cereal-style breakfast (CB), a pattern in which cereal is eaten. We hypothesized that breakfast style may be related to good eating habits. Data from 4274 respondents (67.97% male, 33.03% female, age 48.12 ± 0.19 years), excluding night shift workers and breakfast absentees out of a total of 5535 respondents, were analyzed. The results suggest that Japanese food is linked to the intake of protein sources such as fish, eggs, and soy. Furthermore, it was suggested that Japanese food breakfast is effective for good eating habits, such as not eating irregular amounts of food, not eating snacks, not drinking sweet juices, and having a balanced diet.

Wearable Cameras Reveal Large Intra-Individual Variability in Timing of Eating among Young Adults

Studies have shown that young adults follow less structured eating patterns compared with older cohorts. This may have implications for dietary assessment methods which rely on memory and structured meal patterns. Our aim was to describe the intra-individual variation of eating times in young adults aged 18−30 years. Participants (n = 41) wore an Autographer camera that captured first-person perspective images every 30 s for three consecutive days. All images were timestamped and those showing food consumption were used to extract data such as the timing of the first and last eating occasions (EOs), number of EOs per day, and length of eating window. Intra-individual variability was calculated from these data using composite phase deviation (CPD) and coefficient of variation (CV). The number of individuals with high or very high variability was 28 and 18 for timing of first and last EOs, respectively (CPD > 1.70), and 27 and 17 for number of EOs and eating window, respectively (CV > 20%). In this sample of young adults, the lack of regularity in eating patterns should be considered when selecting a dietary assessment method.

Food insecurity and patterns of dietary intake in a sample of UK adults

The aim of this study was to identify the dietary intake correlates of food insecurity (FI) in UK adults. We recruited groups of low-income participants who were classified as food insecure (n 196) or food secure (n 198). Participants completed up to five 24 h dietary recalls. There was no difference in total energy intake by FI status (β_FI = -0·06, 95 % CI - 0·25, 0·13). Food insecure participants consumed a less diverse diet, as evidenced by fewer distinct foods per meal (β_FI = -0·27, 95 % CI - 0·47, -0·07), and had more variable time gaps between meals (β_FI = 0·21, 95 % CI 0·01, 0·41). These associations corresponded closely to those found in a recent US study using similar measures, suggesting that the dietary intake signature of FI generalises across populations. The findings suggest that the consequences of FI for weight gain and health are not due to increased energy intake. We suggest that there may be important health and metabolic effects of temporal irregularity in dietary intake, which appears to be an important component of FI.

Food Insecurity and Type 2 Diabetes Among Latinos: Examining Neighborhood Cohesion as a Protective Factor

Qualitative work has found that Latino food pantry recipients share food and reciprocally provide social support to their food-insecure neighbors. These findings suggest that neighborhood cohesion (NC) may serve as an important community-level resource that Latinos utilize as a coping mechanism when food-insecure. High levels of NC may be a proxy for instrumental support outside the household and act as a buffer against the adverse health effects of food insecurity including type 2 diabetes (T2D), which is highly sensitive to food insecurity. The purpose of this study was to quantitatively test this theory by examining whether NC moderated the association between T2D and food security (FS) status among Latino adults nationwide. We used data from the 2013-2018 National Health Interview Survey (n = 23,478). We found that FS status was associated with T2D prevalence, with Latino adults having a higher odds of T2D if they had low FS or very low FS compared to their FS counterparts. We also found Latinos adults who reported high NC had a lower odds of T2D compared to those who reported low NC. However, we did not find there was significant interaction between FS status and NC on T2D. NC may instead be a precursor to FS status, rather than a buffer of food insecurity on T2D. Low NC may lead to less instrumental support and tangible benefits that determine FS. Additionally, perceived NC might not align with objective NC and T2D may be too distal of a health outcome to test the protective effect of NC.

Lifestyle changes during the coronavirus disease 2019 pandemic impact metabolic dysfunction-associated fatty liver disease

BACKGROUND AND AIMS

The coronavirus disease 2019 (COVID-19) pandemic precipitated lifestyle changes. We aimed to clarify whether COVID-19-induced lifestyle changes affected the development of metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

This retrospective longitudinal study included 973 participants who underwent health check-ups between 2018 and 2020. We used data from the MedCity21 health examination registry. Participants' clinical characteristics and lifestyle habits were investigated. Independent lifestyle predictors of MAFLD development before the pandemic (2018-2019) and during the pandemic (2019-2020) were identified using logistic regression analysis.

RESULTS

In 2018, 261 (27%) patients were diagnosed with MAFLD. Before the pandemic, 22 patients developed new MAFLD. During this time, routine late-night meals were identified as an independent lifestyle predictor of MAFLD development (hazard ratio [HR] 2.54, 95% confidence interval [CI] 1.02-6.36, P = .046). In contrast, 44 patients developed new MAFLD during the pandemic. During this time, higher daily alcohol intake was identified as an independent lifestyle predictor of MAFLD development (HR 1.03, 95% CI 1.01-1.05, P = .008). In participants aged <60 years, daily alcohol intake and the proportion of participants who ate 2 times/day were significantly higher in patients who developed MAFLD during the pandemic than in those who did not. In participants aged ≥60 years, no lifestyle habits were associated with MAFLD development before or during the pandemic.

CONCLUSIONS

New MAFLD diagnoses increased during the COVID-19 pandemic. Changes in lifestyle factors, particularly in those aged <60 years, must be monitored and addressed as the pandemic continues.

Impact of isoenergetic intake of irregular meal patterns on thermogenesis, glucose metabolism, and appetite: a randomized controlled trial

BACKGROUND

Evidence is emerging that interdaily meal pattern variability potentially affects response such as thermic effect of food (TEF), macronutrient metabolism, and appetite.

OBJECTIVES

To investigate the effect of irregular meal pattern on TEF, glucose, insulin, lipid profile, and appetite regulation in women who are overweight or with obesity and confirmed insulin resistance.

DESIGN

In a randomized crossover trial, 9 women [mean ± SD BMI (in kg/m2): 33.3 ± 3.1] with confirmed insulin resistance consumed a regular (14 d; 6 meals/d) and an irregular (14 d; 3-9 meals/d) meal pattern separated by a 14-d washout interval. Identical foods were provided during the interventions, and at the start and end of each meal pattern, participants attended the laboratory after an overnight fast. Energy expenditure, glucose, insulin, lipids, adiponectin, leptin, glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin were measured at baseline and for 3 h after consumption of a test drink, after which an ad libitum test meal was offered. Subjective appetite ratings were recorded before and after the test drink, after the ad libitum meal, and during the intervention. Continuous interstitial glucose monitoring was undertaken for 7 consecutive days during each intervention.

RESULTS

TEF (over 3 h) was significantly lower postirregular intervention compared with postregular (97.7 ± 19.2 kJ*3 h in postregular visit and 76.7 ± 35.2 kJ*3 h in postirregular visit, paired t test, P = 0.048). Differences in HOMA-IR between the 2 interventions (3.3 ± 1.7 and 3.6 ± 1.6 in postregular and postirregular meal pattern, respectively) were not significant. Net incremental AUC for GLP-1 concentrations (over 3 h) for the postregular meal pattern were higher (864.9 ± 456.1 pmol/L*3 h) than the postirregular meal pattern (487.6 ± 271.7 pmol/L*3 h, paired t test, P = 0.005).

CONCLUSIONS

Following a 14-d period of an irregular meal pattern, TEF was significantly less than following a regular meal pattern, potentially compromising weight management if sustained long term. This study was registered at www.clinicaltrials.gov as NCT02582606.

Management of Obesity and Its Complications in Children and Adolescents

Pediatric overweight/obesity has assumed epidemic proportions in India. It is associated with several significant complications and tracks into adulthood. The mainstay of management is a holistic lifestyle modification that must be adopted by the family as a whole. It involves dietary changes, regular physical activity, and behavioral changes that favor a healthy way of life. Regular follow-up, and attention to keeping up the motivation of the child and family achieves good results. In the present paper, a stepwise approach to prevention and management of childhood obesity is presented along with the recommendations for screening and management of associated complications and the role of pharmacotherapy and bariatric surgery.

Effects of regular breakfast habits on metabolic and cardiovascular diseases: A protocol for systematic review and meta-analysis

BACKGROUND

Breakfast, which is considered as an important meal of the day, is being ignored by an increasing number of people as the pace of modern life accelerates. Although a large number of previous studies have reported the relationship between skipping breakfast and type 2 diabetes mellitus, most of them were cross-sectional studies. It remains unclear how skipping breakfast affects such specific cardio-metabolic diseases as hypertension, strokes and hypercholesterolemia.

METHODS

The protocols and reports of this meta-analysis are based on a meta-analysis of observational studies in epidemiological guidelines (MOOSE). Relevant studies were systematically retrieved from PubMed, Embase, Web of Science and the Cochrane Library, and were restricted to English from the inception to May 10, 2019. All the results were obtained by RRs, and outcomes of interests should include the occurrence of cardiovascular and metabolic diseases.

RESULTS

Fourteen cohort studies in total were eventually included. Compared with people having breakfast frequency≦3times/week, those with a frequency>3 times/week have reduced the risk of type 2 diabetes mellitus, obesity, Metabolic Syndrome, Low high-density lipoprotein cholesterolemia, Cardiovascular Diseases, cardiovascular Mortality, hypertension and strokes, with (RR = 0.8 [95% CI: 0.7-0.91], P = .142, I2 = 37.6%), (RR = 0.74 [95% CI: 0.59-0.94], P < .001, I2 = 89%), (RR = 0.86 [95% CI:0.75-0.99], P = .512, I2 = 0%), (RR = 0.75 [95% CI:0.61-0.93], P = .643, I2 = 0%), (RR = 0.87 [95% CI:0.81-0.93], P = .479, I2 = 0%), (RR = 0.63 [95% CI:0.51-0.78], P = .396, I2 = 0%), (RR = 0.92 [95% CI:0.86-0.98], P = .419, I2 = 0.7%), and (RR = 0.89 [95% CI:0.79-0.99], P = .238, I2 = 29%), respectively.

CONCLUSIONS

A regular daily breakfast habit benefits the cardio-metabolism to a great extent, reducing the risk of Cardiovascular Diseases, type 2 diabetes mellitus, obesity, hypertension, strokes, Metabolic Syndrome, cardiovascular Mortality, Low high-density lipoprotein cholesterolemia, and Abdominal obesity, while it is not significantly related to hypercholesterolemia and coronary heart disease regardless of gender. Nevertheless, skipping breakfast once a week may greatly reduce the benefits of cardio-metabolism. Therefore, public institutions should promote and encourage citizens to cultivate regular daily breakfast habits.

Variability in Daily Eating Patterns and Eating Jetlag Are Associated With Worsened Cardiometabolic Risk Profiles in the American Heart Association Go Red for Women Strategically Focused Research Network

Background

Sleep variability and social jetlag are associated with adverse cardiometabolic outcomes via circadian disruption. Variable eating patterns also lead to circadian disruption, but associations with cardiometabolic health are unknown.

Methods and Results

Women (n=115, mean age: 33±12 years) completed a 1‐week food record using the Automated Self‐Administered 24‐Hour Dietary Assessment Tool at baseline and 1 year. Timing of first and last eating occasions, nightly fasting duration, and %kcal consumed after 5 pm (%kcal 5 pm) and 8 pm (%kcal 8 pm) were estimated. Day‐to‐day eating variability was assessed from the SD of these variables. Eating jetlag was defined as weekday‐weekend differences in these metrics. Multivariable‐adjusted linear models examined cross‐sectional and longitudinal associations of day‐to‐day variability and eating jetlag metrics with cardiometabolic risk. Greater jetlag in eating start time, nightly fasting duration, and %kcal 8 pm related to higher body mass index and waist circumference at baseline (P<0.05). In longitudinal analyses, a 10% increase in %kcal 8 pm SD predicted increased body mass index (β, 0.52; 95% CI, 0.23–0.81) and waist circumference (β, 1.73; 95% CI, 0.58–2.87); greater %kcal 8 pm weekday‐weekend differences predicted higher body mass index (β, 0.25; 95% CI, 0.07–0.43). Every 30‐minute increase in nightly fasting duration SD predicted increased diastolic blood pressure (β, 0.95; 95% CI, 0.40–1.50); an equivalent increase in nightly fasting duration weekday‐weekend differences predicted higher systolic blood pressure (β, 0.58; 95% CI, 0.11–1.05) and diastolic blood pressure (β, 0.45; 95% CI, 0.10–0.80). Per 10% increase in %kcal 5 pm SD, there were 2.98 mm Hg (95% CI, 0.04–5.92) and 2.37mm Hg (95% CI, 0.19–4.55) increases in systolic blood pressure and diastolic blood pressure; greater %kcal 5 pm weekday‐weekend differences predicted increased systolic blood pressure (β, 1.83; 95% CI, 0.30–3.36). For hemoglobin A1c, every 30‐minute increase in eating start and end time SD and 10% increase in %kcal 5 pm SD predicted 0.09% (95% CI, 0.03–0.15), 0.06% (95% CI, 0.001–0.12), and 0.23% (95% CI, 0.07–0.39) increases, respectively.

Conclusions

Variable eating patterns predicted increased blood pressure and adiposity and worse glycemic control. Findings warrant confirmation in population‐based cohorts and intervention studies.

Intermittent fasting: from calories to time restriction

The global human population has recently experienced an increase in life expectancy with a mounting concern about the steady rise in the incidence of age-associated chronic diseases and socio-economic burden. Calorie restriction (CR), the reduction of energy intake without malnutrition, is a dietary manipulation that can increase health and longevity in most model organisms. However, the practice of CR in day-to-day life is a challenging long-term goal for human intervention. Recently, daily fasting length and periodicity have emerged as potential drivers behind CR's beneficial health effects. Numerous strategies and eating patterns have been successfully developed to recapitulate many of CR's benefits without its austerity. These novel feeding protocols range from shortened meal timing designed to interact with our circadian system (e.g., daily time-restricted feeding) to more extended fasting regimens known as intermittent fasting. Here, we provide a glimpse of the current status of knowledge on different strategies to reap the benefits of CR on metabolic health in murine models and in humans, without the rigor of continuous reduction in caloric intake as presented at the USU State of the Science Symposium.

Effects of intermittent (5:2) or continuous energy restriction on basal and postprandial metabolism: a randomised study in normal-weight, young participants

BACKGROUND/OBJECTIVES

Intermittent energy restriction (IER) may overcome poor long-term adherence with continuous energy restriction (CER), for weight reduction. We compared the effects of IER with CER for fasting and postprandial metabolism and appetite in metabolically healthy participants, in whom excess weight would not confound intrinsic metabolic differences.

SUBJECTS/METHODS

In a 2-week randomised, parallel trial, 16 young, healthy-weight participants were assigned to either CER (20% below estimated energy requirements (EER)) or 5:2 IER (70% below EER on 2 non-consecutive days; 5 days at EER, per week). Metabolic and appetite regulation markers were assessed before and for 3 h after a liquid breakfast; followed by an ad libitum lunch; pre- and post-intervention.

RESULTS

Weight loss was similar in both groups: -2.5 (95% CI, -3.4, -1.6) kg for 5:2 IER vs. -2.3 (-2.9, -1.7) kg for CER. There were no differences between groups for postprandial incremental area under the curve for serum insulin, blood glucose or subjective appetite ratings. Compared with CER, 5:2 IER led to a reduction in fasting blood glucose concentrations (treatment-by-time interaction, P = 0.018, η²_p = 0.14). Similarly, compared with CER, there were beneficial changes in fasting composite appetite scores after 5:2 IER (treatment-by-time interaction, P = 0.0003, η²_p = 0.35).

CONCLUSIONS

There were no significant differences in postprandial insulinaemic, glycaemic or appetite responses between treatments. However, 5:2 IER resulted in greater improvements in fasting blood glucose, and beneficial changes in fasting subjective appetite ratings.

Psychosomatic Stress Responses and Sleep Disturbance Mediate the Effects of Irregular Mealtimes on Presenteeism

BACKGROUND

Presenteeism is the loss of work productivity of workers owing to physical and mental problems, and its socioeconomic effects are greater than those of absenteeism. Presenteeism is caused by psychological and physical dysfunctions. On the other hand, the regularity of mealtimes is an important factor associated with physical and mental health conditions. We hence assessed the association among the irregularity of mealtimes, presenteeism, psychological and physical stress responses, and sleep disturbance in office workers in companies.

METHODS

From May to December 2017, the data of 2905 participants who had given their consent to use their information for academic purposes, and answered a questionnaire about the survey and their lifestyle were collected. Path analysis was performed to analyze the association between the irregularity of mealtimes, psychosomatic symptoms (Brief Job Stress Questionnaire), sleep disturbance (Pittsburgh Sleep Questionnaire), and presenteeism (Work Limitations Questionnaire).

RESULTS

The direct effect of the irregularity of mealtimes on presenteeism was significant but weak. However, the irregularity of mealtimes had a strong effect on presenteeism indirectly through psychological and physical stress responses and sleep disturbance.

CONCLUSION

Psychological and physical stress responses and sleep disturbance were identified as mediating factors of the effects of irregularity of mealtimes on presenteeism.

Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns

The circadian timing system governs daily biological rhythms, synchronising physiology and behaviour to the temporal world. External time cues, including the light-dark cycle and timing of food intake, provide daily signals for entrainment of the central, master circadian clock in the hypothalamic suprachiasmatic nuclei (SCN), and of metabolic rhythms in peripheral tissues, respectively. Chrono-nutrition is an emerging field building on the relationship between temporal eating patterns, circadian rhythms, and metabolic health. Evidence from both animal and human research demonstrates adverse metabolic consequences of circadian disruption. Conversely, a growing body of evidence indicates that aligning food intake to periods of the day when circadian rhythms in metabolic processes are optimised for nutrition may be effective for improving metabolic health. Circadian rhythms in glucose and lipid homeostasis, insulin responsiveness and sensitivity, energy expenditure, and postprandial metabolism, may favour eating patterns characterised by earlier temporal distribution of energy. This review details the molecular basis for metabolic clocks, the regulation of feeding behaviour, and the evidence for meal timing as an entraining signal for the circadian system in animal models. The epidemiology of temporal eating patterns in humans is examined, together with evidence from human intervention studies investigating the metabolic effects of morning compared to evening energy intake, and emerging chrono-nutrition interventions such as time-restricted feeding. Chrono-nutrition may have therapeutic application for individuals with and at-risk of metabolic disease and convey health benefits within the general population.

Impacts of Dietary Macronutrient Pattern on Adolescent Body Composition and Metabolic Risk: Current and Future Health Status-A Narrative Review

Obesity, particularly in childhood and adolescence, is one of the serious public health problems worldwide. According to the World Health Organization, 10% of young people aged 5-17 years are obese, which is rapidly increasing around the world. Furthermore, approximately 80% of adolescents who become obese develop bodyweight-related health problems in adulthood. Eating habits and lifestyles play important roles in forming body composition and metabolic status. Changes in body composition in adolescence, the period in which secondary sex characteristics begin to develop, can alter hormonal and metabolic status, can consequently affect health status and the risk of developing chronic diseases in adulthood, and moreover may have an impact on probable body composition and metabolic status in the next generation. Here, we reviewed cross-sectional and interventional studies to analyze the role of dietary patterns focusing on macronutrient intake in growth, body composition, and metabolic changes in adolescents. These findings provide insights into optimal dietary guidelines for healthy growth with accretion of adequate body composition in adolescence, and provide an effective strategy for preventing and managing the risk of obesity-related metabolic disease in adulthood, with the additional benefit of providing potential benefits for the next generation's health.

The Future of Shift Work: Circadian Biology Meets Personalised Medicine and Behavioural Science

Shift work is commonplace in modern societies, and shift workers are predisposed to the development of numerous chronic diseases. Disruptions to the circadian systems of shift workers are considered important contributors to the biological dysfunction these people frequently experience. Because of this, understanding how to alter shift work and zeitgeber (time cue) schedules to enhance circadian system function is likely to be key to improving the health of shift workers. While light exposure is the most important zeitgeber for the central clock in the circadian system, diet and exercise are plausible zeitgebers for circadian clocks in many tissues. We know little about how different zeitgebers interact and how to tailor zeitgeber schedules to the needs of individuals; however, in this review we share some guidelines to help shift workers adapt to their work schedules based on our current understanding of circadian biology. We focus in particular on the importance of diet timing and composition. Going forward, developments in phenotyping and "envirotyping" methods may be important to understanding how to optimise shift work. Non-invasive, multimodal, comprehensive phenotyping using multiple sources of time-stamped data may yield insights that are critical to the care of shift workers. Finally, the impact of these advances will be reduced without modifications to work environments to make it easier for shift workers to engage in behaviours conducive to their health. Integrating findings from behavioural science and ergonomics may help shift workers make healthier choices, thereby amplifying the beneficial effects of improved lifestyle prescriptions for these people.

Consistent sleep onset and maintenance of body weight after weight loss: An analysis of data from the NoHoW trial

BACKGROUND

Several studies have suggested that reduced sleep duration and quality are associated with an increased risk of obesity and related metabolic disorders, but the role of sleep in long-term weight loss maintenance (WLM) has not been thoroughly explored using prospective data.

METHODS AND FINDINGS

The present study is an ancillary study based on data collected on participants from the Navigating to a Healthy Weight (NoHoW) trial, for which the aim was to test the efficacy of an evidence-based digital toolkit, targeting self-regulation, motivation, and emotion regulation, on WLM among 1,627 British, Danish, and Portuguese adults. Before enrolment, participants had achieved a weight loss of ≥5% and had a BMI of ≥25 kg/m2 prior to losing weight. Participants were enrolled between March 2017 and March 2018 and followed during the subsequent 12-month period for change in weight (primary trial outcome), body composition, metabolic markers, diet, physical activity, sleep, and psychological mediators/moderators of WLM (secondary trial outcomes). For the present study, a total of 967 NoHoW participants were included, of which 69.6% were women, the mean age was 45.8 years (SD 11.5), the mean baseline BMI was 29.5 kg/m2 (SD 5.1), and the mean weight loss prior to baseline assessments was 11.4 kg (SD 6.4). Objectively measured sleep was collected using the Fitbit Charge 2 (FC2), from which sleep duration, sleep duration variability, sleep onset, and sleep onset variability were assessed across 14 days close to baseline examinations. The primary outcomes were 12-month changes in body weight (BW) and body fat percentage (BF%). The secondary outcomes were 12-month changes in obesity-related metabolic markers (blood pressure, low- and high-density lipoproteins [LDL and HDL], triglycerides [TGs], and glycated haemoglobin [HbA1c]). Analysis of covariance and multivariate linear regressions were conducted with sleep-related variables as explanatory and subsequent changes in BW, BF%, and metabolic markers as response variables. We found no evidence that sleep duration, sleep duration variability, or sleep onset were associated with 12-month weight regain or change in BF%. A higher between-day variability in sleep onset, assessed using the standard deviation across all nights recorded, was associated with weight regain (0.55 kg per hour [95% CI 0.10 to 0.99]; P = 0.016) and an increase in BF% (0.41% per hour [95% CI 0.04 to 0.78]; P = 0.031). Analyses of the secondary outcomes showed that a higher between-day variability in sleep duration was associated with an increase in HbA1c (0.02% per hour [95% CI 0.00 to 0.05]; P = 0.045). Participants with a sleep onset between 19:00 and 22:00 had the greatest reduction in diastolic blood pressure (DBP) (P = 0.02) but also the most pronounced increase in TGs (P = 0.03). The main limitation of this study is the observational design. Hence, the observed associations do not necessarily reflect causal effects.

CONCLUSION

Our results suggest that maintaining a consistent sleep onset is associated with improved WLM and body composition. Sleep onset and variability in sleep duration may be associated with subsequent change in different obesity-related metabolic markers, but due to multiple-testing, the secondary exploratory outcomes should be interpreted cautiously.

TRIAL REGISTRATION

The trial was registered with the ISRCTN registry (ISRCTN88405328).

Disruption in daily eating-fasting and activity-rest cycles in Indian adolescents attending school

A lifestyle with erratic eating patterns and habits predisposes youngsters to obesity. Through a two-phase feasibility study among Indian students living in the Delhi area, we longitudinally examined the following: (1) the daily eating-fasting cycles of students (N = 34) in school and college using smartphones as they transition from high school (aged 13–15 years; n_IX = 13) to higher secondary school (HSSS; 16–18 years; n_XII = 9) to their first year (FY) of college (18–19 years; n_FC = 12); and (2) daily activity-rest cycles and light-dark exposure of 31 higher secondary school students (HSSS) using actigraphy. In phase 1, students’ food data were analyzed for temporal details of eating events and observable differences in diet composition, such as an energy-dense diet (fast food (FF)), as confounding factors of circadian health. Overall, the mean eating duration in high school, higher secondary and FY college students ranged from 14.1 to 16.2h. HSSS exhibited the shortest night fasting. Although FY college students exhibited the highest fast food percentage (FF%), a positive correlation between body mass index (BMI) and FF% was observed only among HSSS. Furthermore, the body weight of HSSS was significantly higher, indicating that FF, untimely eating and reduced night fasting were important obesity-associated factors in adolescents. Reduced night fasting duration was also related to shorter sleep in HSSS. Therefore, food data were supplemented with wrist actigraphy, i.e., activity-rest data, in HSSS. Actigraphy externally validated the increased obesogenic consequences of deregulated eating rhythms in HSSS. CamNtech motion watches were used to assess the relationship between disturbed activity cycles of HSSS and other circadian clock-related rhythms, such as sleep. Less than 50% of Indian HSSS slept 6 hours or more per night. Seven of 31 students remained awake throughout the night, during which they had more than 20% of their daily light exposure. Three nonparametric circadian rhythm analysis (NPCRA) variables revealed circadian disruption of activity in HSSS. The present study suggests that inappropriate timing and quality of food and sleep disturbances are important determinants of circadian disruptions in adolescents attending school.

Eating frequency and weight status in Portuguese children aged 3-9 years: results from the cross-sectional National Food, Nutrition and Physical Activity Survey 2015-2016

OBJECTIVE

To evaluate daily eating frequency (main meals and snacks) in relation to weight status in children aged 3-9 years, representative of the Portuguese population.

DESIGN

Cross-sectional study. Dietary intake was estimated as the mean of two non-consecutive days of food diaries, followed by face-to-face interviews. Weight and height were measured by trained observers. Eating occasions (EO) were defined by the children's caregiver; an EO was considered separate if the time of consumption was different from other EO and it provided at least 209 kJ (50 kcal). Main meals defined as 'breakfast', 'lunch' and 'dinner' could be selected only once per day. The remaining EO were considered snacks. The association between eating frequency and overweight/obesity was evaluated through logistic regressions weighted for the population distribution.

SETTING

National Food, Nutrition and Physical Activity Survey of the Portuguese population, 2015-2016.

PARTICIPANTS

Portuguese children aged 3-9 years with complete dietary data and anthropometric measurements (n 517).

RESULTS

Overall, the number of daily EO ranged from 3·5 to 11, and on average children had 5·7 daily EO. After adjustment for child's sex, age and total energy intake, and considering only plausible energy intake reporters, having < 3 snacks/d was positively associated with being overweight/obese (OR = 1·98; 95 % CI 1·00, 3·90), compared with having ≥ 3 snacks/d.

CONCLUSIONS

Lower daily frequency of EO was associated with increased odds of being overweight or obese in children. A higher eating frequency, maintaining the same energy intake, seems to contribute to a healthy body weight in children.

The Influence of Meal Frequency and Timing on Health in Humans: The Role of Fasting

The influence of meal frequency and timing on health and disease has been a topic of interest for many years. While epidemiological evidence indicates an association between higher meal frequencies and lower disease risk, experimental trials have shown conflicting results. Furthermore, recent prospective research has demonstrated a significant increase in disease risk with a high meal frequency (≥6 meals/day) as compared to a low meal frequency (1⁻2 meals/day). Apart from meal frequency and timing we also have to consider breakfast consumption and the distribution of daily energy intake, caloric restriction, and night-time eating. A central role in this complex scenario is played by the fasting period length between two meals. The physiological underpinning of these interconnected variables may be through internal circadian clocks, and food consumption that is asynchronous with natural circadian rhythms may exert adverse health effects and increase disease risk. Additionally, alterations in meal frequency and meal timing have the potential to influence energy and macronutrient intake.A regular meal pattern including breakfast consumption, consuming a higher proportion of energy early in the day, reduced meal frequency (i.e., 2⁻3 meals/day), and regular fasting periods may provide physiological benefits such as reduced inflammation, improved circadian rhythmicity, increased autophagy and stress resistance, and modulation of the gut microbiota.

Relationship of evening meal with sleep quality in obese individuals with obstructive sleep apnea

PURPOSE

To determine the relationship between habitual food intake, resting energy expenditure and sleep pattern in obstructive sleep apnea (OSA) patients.

METHODS

Forty-five OSA obese males were included in the study. All participants were submitted to nocturnal polysomnography, body composition measurements by plethysmography, resting energy expenditure (REE) analysis by indirect calorimetry and they filled in a 3-day food record.

RESULTS

No differences in body composition, REE and food intake were found between the moderate and severe OSA groups. A trend towards higher energy intake in the severe OSA group was observed, compared to the moderate group (p = 0.08). Significant associations between apnea-hypopnea index (AHI) with body weight, body mass index (BMI) and resting energy expenditure (REE) were found. Higher food intake in the evening period was positively correlated with sleep stage NREM1, arousal index, and AHI and negatively correlated with sleep stage NREM3 and sleep efficiency. A multivariate linear regression showed energy intake at breakfast to be a significant negative predictor of AHI; protein intake (g/kg) showed a positive association, while energy intake at breakfast and at dinner were negative predictors of sleep efficiency; and energy intake at dinner was a negative predictor of stage NREM1 sleep.

CONCLUSIONS

We conclude that higher amounts of food intake during the evening period may diminish sleep quality in moderate and severe sleep apnea patients. In addition, despite observing no differences between OSA severity groups, a moderate correlation between REE and sleep quality and OSA exists.

Food-Insecure Women Eat a Less Diverse Diet in a More Temporally Variable Way: Evidence from the US National Health and Nutrition Examination Survey, 2013-4

Food insecurity is associated with high body weight amongst women, but not men, in high-income countries. Previous research using food recalls suggests that the total energy intake of food-insecure women is not elevated, though macronutrient composition may differ from that of food-secure women. There is limited evidence on temporal patterns of food consumption. Here, we used food recalls from women in the 2013-4 cycle of the National Health and Nutrition Examination Survey (NHANES, n = 2798) to characterise temporal patterns of food consumption in relation to food insecurity. Compared to the food-secure, food-insecure women had more variable time gaps between eating; ate a smaller and less variable number of distinct foods at a time; were more variable from day to day in their time of first consumption; were more variable from day to day in the number of times they ate; and consumed relatively more carbohydrate, less protein, and less fibre. However, their overall energy intake was no higher. Food-insecure women had higher BMIs (2.25 kg/m²), and around 15% of the BMI difference between food-insecure and food-secure women was accounted for by their more variable time gaps between eating, their lower diversity of foods, and their lower fibre consumption. Food insecurity is associated with measureable differences in the temporal pattern of food consumption, and some of these differences shed light on how food-insecure women come to have higher body weights.

Randomized Trial of a High Protein, Partial Meal Replacement Program with or without Alternate Day Fasting: Similar Effects on Weight Loss, Retention Status, Nutritional, Metabolic, and Behavioral Outcomes

Higher-protein diets, meal replacements, and greater early weight loss have separately been associated with greater weight loss. We compared a high-protein, meal replacement program with daily energy restriction (DER) to one which provided greater energy restriction adding alternate day fasting (ADF + DER; alternating days of modified-fasting and DER plus 1 ad libitum day/week) on retention, weight loss, physiological, nutritional, and behavioral markers. Participants were randomized to ADF + DER or DER for 16 weeks (n = 162, age 40 ± 8 years BMI 36 ± 6 kg/m² (Mean ± SD)) plus 8 weeks weight maintenance. At week 16 weight change was -10.7 ± 0.5 kg and -11.2 ± 0.6 kg in ADF + DER and DER groups (treatment NS). Fat mass, visceral adipose tissue, and lean mass (p < 0.05) were similarly reduced between treatments. Weight loss was sustained to 24 weeks (treatment NS). Fasting LDL-cholesterol, triglycerides, insulin, hsCRP, glucose, and blood pressure all improved (p < 0.05; treatment NS). Transferrin saturation, ferritin, serum zinc, folate, and B12 improved (p < 0.05; treatment NS). Plasma thiamine and vitamin D levels decreased, reflecting lower carbohydrate intakes and seasonal changes, respectively. Food cravings, quality of life, and mood improved (treatment NS). Energy, fatigue, and pain improved slightly more in DER (p < 0.05). This study supports the use of higher protein, meal replacement programs with or without ADF in weight management.

Improving cardiometabolic and mental health in women with gestational diabetes mellitus and their offspring: study protocol for MySweetHeart Trial, a randomised controlled trial

INTRODUCTION

Gestational diabetes mellitus (GDM) carries prenatal and perinatal risk for the mother and her offspring as well as longer-term risks for both the mother (obesity, diabetes, cardiovascular disease) and her child (obesity, type 2 diabetes). Compared with women without GDM, women with GDM are twice as likely to develop perinatal or postpartum depression. Lifestyle interventions for GDM are generally limited to physical activity and/or nutrition, often focus separately on the mother or the child and take place either during or after pregnancy, while their results are inconsistent. To increase efficacy of intervention, the multifactorial origins of GDM and the tight link between mental and metabolic as well as maternal and child health need to be heeded. This calls for an interdisciplinary transgenerational approach starting in, but continuing beyond pregnancy.

METHODS AND ANALYSIS

This randomised controlled trial will assess the effect of a multidimensional interdisciplinary lifestyle and psychosocial intervention aimed at improving the metabolic and mental health of 200 women with GDM and their offspring. Women with GDM at 24-32 weeks gestational age who understand French or English, and their offspring and partners can participate. The intervention components will be delivered on top of usual care during pregnancy and the first year postpartum. Metabolic and mental health outcomes will be measured at 24-32 weeks of pregnancy, shortly after birth and at 6-8 weeks and 1 year after childbirth. Data will be analysed using intention-to-treat analyses. The MySweetHeart Trial is linked to the MySweetHeart Cohort (clinicaltrials.gov/ct2/show/NCT02872974).

ETHICS AND DISSEMINATION

We will disseminate the findings through regional, national and international conferences and through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02890693; Pre-results.

Sleep duration, nightshift work, and the timing of meals and urinary levels of 8-isoprostane and 6-sulfatoxymelatonin in Japanese women

It has been hypothesized that disruption of circadian rhythms affects human health. Shift work and sleep deprivation are thought to disrupt the normal light-dark cycle, although the disruption due to shiftwork may be dependent on sleep deprivation. Both conditions have been suggested to be associated with an increased risk of cardiometabolic disorders. Non-photic environmental factors, such as the timing of eating, are also thought to regulate circadian rhythm and thus, may have effects on health, but the evidence from human studies is scarce. Oxidative stress is a risk factor of cardiometabolic disorders. Some laboratory studies suggest an involvement of circadian clock genes in the regulation of the redox system. The present study aimed to examine the association of sleeping habits, nightshift work, and the timing of meals with urinary levels of 8-isoprostane, a marker of oxidative stress, and 6-sulfatoxymelatonin, the principal metabolite of melatonin. Study subjects were 542 women who had previously attended a breast cancer mass screening in a community in Japan. Information on bedtimes and wake-up times, history of nightshift work, and the timing of meals was obtained by a self-administered questionnaire. The 8-isoprostane and 6-sulfatoxymelatonin were measured using the first morning void of urine and expressed per mg of creatinine. The geometric mean of 8-isoprostane levels was 12.1% higher in women with ≤6 hours of sleep than that in those with >8 hours of sleep on weekdays, and longer sleep duration on weekdays was significantly associated with lower urinary levels of 8-isoprostane after controlling for covariates (p for trend = 0.04). Women who were currently working the nightshift had a 33.3% higher geometric mean of 8-isoprostane levels than those who were not working nightshift (p = 0.03). Urinary 6-sulfatoxymelatonin levels were unrelated to sleep habits or nightshift work. Women who ate breakfast at irregular times had a 19.8% higher geometric mean of 8-isoprostane levels than those who ate breakfast at a regular time or who did not eat (p = 0.02). Women who ate nighttime snacks at irregular times had a 16.2% higher geometric mean of 8-isoprostane levels than those who did not eat nighttime snacks or who ate nighttime snacks at a regular time (p = 0.003). Among women who ate dinner at a regular time, earlier times for dinner were associated with higher 8-isoprostane and 6-sulfatoxymelatonin levels (p values for trends were 0.01 and 0.02, respectively). However, the times of dinner and nighttime snack are overlapping, and the time of last meal of the day was not associated with 8-isoprostane and 6-sulfatoxymelatonin levels. The time of breakfast or lunch was not associated with these biomarkers among women who ate the meal at regular times. Disturbing the rhythmicity of daily life may be associated with oxidative stress.

Relationship of Sleep Duration with Sociodemographic Characteristics, Lifestyle, Mental Health, and Chronic Diseases in a Large Chinese Adult Population

STUDY OBJECTIVES

Pattern of sleep duration and its correlates have rarely been reported in China. This study examined the sleep duration and its relationship with sociodemographic variables, lifestyle, mental health, and chronic diseases in a large Chinese adult population.

METHODS

This cross-sectional study used multistage stratified cluster sampling. A total of 17,320 participants from Jilin province were selected and interviewed using standardized assessment tools. Basic socio-demographic and clinical data were collected. Sleep duration was classified as short (< 7 h per day), long (> 9 h per day) and medium sleep (7-9 h per day).

RESULTS

The mean age of the sample was 42.60 ± 10.60 y, with 51.4% being female. The mean sleep duration was 7.31 ± 1.44 h. Short and long sleepers accounted for 30.9% and 6.9% of the sample, respectively. Multinomial logistic regression analysis revealed that older age, current smoking, irregular meal pattern, lack of physical exercise, poor mental health, and chronic diseases or multimorbidity were positively associated with short sleep. Being married and living in rural areas were, however, negatively associated with short sleep. In addition, living in rural area, current smoking, current alcohol use and lack of physical exercise were positively associated with long sleep, while older age and lower education were negatively associated with long sleep.

CONCLUSION

Given the high frequency of short sleep and its negative effect on health, health professionals should pay more attention to sleep patterns in general health care. Nationwide epidemiologic surveys in China are needed to further explore the relationship between sleep duration and health.