Nibbling versus gorging: metabolic advantages of increased meal frequency

Association of chrononutrition patterns with biological aging: evidence from a nationally representative cross-sectional study

Previous studies mostly focused on the benefits of caloric restriction and fasting on longevity. However, whether the timing and frequency of eating affect aging remains unclear. Here, we investigated the associations between chrononutrition patterns and biological aging, and explored whether and to what extent dietary inflammation mediated this association. 16 531 adults aged 20 to 84 years from the National Health and Nutrition Examination Survey were collected. Chrononutrition patterns were determined with two 24-hour dietary recalls. Phenotypic age was calculated to reflect the biological aging status. The dietary inflammatory index (DII) was used to assess the dietary inflammation. After adjustment of the survey weight and multiple covariates including total energy intake, participants in the third tertile of the time of the first meal (mean 10 : 26) exhibited more advanced biological age (β 0.64; 95% CI, 0.26-1.00) and a higher incidence of accelerated aging (odds ratio (OR) 1.25; 95% CI, 1.06-1.47) compared to those of the first tertile (mean 6 : 14). Higher eating frequency was associated with delayed biological aging in both multivariable linear (β -0.31; 95% CI, -0.44 to -0.19) and logistic regression model (OR 0.90; 95% CI, 0.85-0.95). Furthermore, we found that DII rather than metabolic factors mediated the inverse association between eating frequency and biological aging (mediation proportion 24.67%; 95% CI, 19.83%-32.00%). Our findings demonstrated the association between chrononutrition patterns and biological aging among the US general population and the potential role of dietary inflammation in this association, suggesting that modifying chrononutrition patterns may be a practical and cost-effective strategy for combating aging.

Age-specific association between meal-skipping patterns and the risk of hyperglycemia in Korean adults: a national cross-sectional study using the KNHANES data

BACKGROUND

Glucose metabolism regulation is influenced by age and meal skipping, although research on their interplay with hyperglycemia remains limited. This study aims to explore the intricate relationship between meal-skipping patterns and hyperglycemia risk across distinct age groups in South Korean adults.

METHODS

Utilizing data from the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2013 to 2020, comprising 28,530 individuals aged 19 years and older, this study employed multivariable logistic regression models to examine the associations between meal-skipping patterns and the risk of hyperglycemia.

RESULTS

Meal-skipping patterns were categorized into three groups: no skipping (NS), skipping breakfast (SB), and skipping dinner (SD). Age groups were defined as "young" (aged 19-44), "middle-aged" (aged 45-64), and "elderly" adults (over 65 years old). Among "young" adults, SB was associated with a 1.33-fold higher risk of hyperglycemia (OR = 1.33, 95% CI = 1.14-1.54) compared to NS. Conversely, in "elderly" adults, SD was linked to a 0.49-fold reduced risk (95% CI = 0.29-0.82) when compared to NS. Additionally, we observed that the Korean Health Eating Index (KHEI) scores, representing the quality of diet on a scale of 0 to 100, were consistently lower in SB compared to NS across all age groups. Intriguingly, specifically among the "elderly" group, this score was higher in SD compared to NS (p < 0.001).

CONCLUSIONS

This study demonstrates age-specific variations in the association between meal-skipping patterns and the risk of hyperglycemia.

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.

Chronomedicine Insights: Evaluating the Impact of Time-Restricted Meal Intake on Lipid Profile Parameters Among Individuals With Type 2 Diabetes in Northern India

INTRODUCTION

Time-restricted meal intake (TRM) has shown potential benefits such as enhanced insulin sensitivity, lowered blood sugar levels, and possible weight loss in individuals with type 2 diabetes mellitus (T2DM). Our study aimed to investigate the impact of TRM on lipid profile parameters such as total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) in fasting conditions in T2DM patients.

METHODS

In total, 400 patients from the endocrinology department at King George's Medical University (KGMU), Lucknow were enrolled in this study, adhering to the guidelines of the American Diabetes Association (ADA). Male and female patients with recently diagnosed T2DM (in the past five years), aged between 25 to 60 years, on oral anti-diabetic therapy excluding insulin, expressing willingness to provide written consent and to adhere to TRM were included in the TRM group. It was a longitudinal study as diabetic dyslipidemia is primarily caused by insulin resistance and nutritional reasons and we wanted to assess the effect of TRM on lipid profile in T2DM patients. Patients were enrolled via simple random sampling using the random number table method (computerized). The TRM group had an early dinner at 7 pm whereas the control group was of non-TRM/late-night eaters. TRM group was given comprehensive guidance including strategies to manage hunger, permissible beverage options (water and prescribed medication) during the fasting period, and daily maintenance of a diary documenting their timing, type, and quantity of food intake which they were requested to bring fortnightly. Emphasis was placed on recording even minor dietary items consumed throughout the day. The TRM group consumed food ad libitum during a 12-hour eating window from breakfast at 7 am to dinner at 7 pm. Data distribution was non-parametric. Mann-Whitney U test compared TRM and control group using mean values at baseline and follow-ups. Analysis used GraphPad Prism 9.2.0 software (GraphPad Inc., La Jolla, CA). A p-value less than 0.05 (p < 0.05) was considered statistically significant.

RESULTS

A total of 127 patients were lost to follow-up, resulting in 273 patients who completed the study. The mean value of TC in the TRM and non-TRM groups using the Mann-Whitney U test registered a highly significant p-value <0.0001 at 18 months, with a decrease of 14.17% from baseline in the TRM group and a decrease of 1.53% from baseline in the non-TRM group. The TRM group had a decrease of 24.75% in TG from a baseline value of 145.4±41.9, whereas the non-TRM group showed a decrease of 2.2% from a baseline value of 154.7±37.30 (p-value <0.0001). The TRM group showed an increase of 9.25% in HDL from a baseline value of 50.14±8.58; the non-TRM group showed an increase of 0.82% from a baseline value of 48.62±9.31 (p-value <0.0001). TRM group showed a decrease of 8.62% in LDL from a baseline value of 68.20±16.2 while the non-TRM group showed an increase of 1.54% from a baseline value of 65.38±19.3 (p-value <0.0002). The TRM group showed a decrease of 13.97% in VLDL from a baseline value of 32.20±18.7; the non-TRM group showed an increase of 4% from a baseline value of 30.16±24.2 (p-value <0.0001).

CONCLUSION

Our study's promising results underscore the potential of TRM as an effective strategy for managing dyslipidemia in individuals with T2DM, even over prolonged periods.

Effect of feeding frequency on reproductive performances and stress responses in gestating sows

The objective of this study was to investigate the influence of feeding frequency on a sow's reproductive performance and stress response during gestation. A total of twenty multiparous sows (Yorkshire × Landrace) were used in a completely randomized design based on their parity, body weight (BW), and backfat thickness (BFT), and the sows were allotted to two different feeding systems: 1) once daily feeding (OF) and 2) twice daily feeding (TF) in corn-soybean meal based diets. The gestation diet was formulated to contain 3,265 kcal of metabolizable energy (ME) / kg, 12.90% of crude protein (CP), and 0.75 % of total lysine. The lactation diet was formulated to contain 3,265 kcal of ME / kg, 16.80% of CP, and 1.08% of total lysine and provided ad libitum during lactation. In gestation, sow BFT and BF changes were not affected by feeding frequency, but higher BW and BW gain from day 35 to 90 and day 35 to 110 were observed in OF sow (p < 0.10). In lactation, feeding frequency did not influence on BW, BW gain, BFT, BF changes, average daily feed intake, and wean-to-estrus interval. Also, there were no differences in litter size, litter weight and piglet weight in lactating sows. OF sows had higher (p < 0.05; p < 0.10) protein, solid-not-fat, and total solid concentrations in colostrum compared to TF sows, while OF sows had a lower (p < 0.05) lactose concentration in colostrum compared to TF sows. Sows in OF showed significantly lower average daily water consumption (ADWC) from day 35 to 110 of gestation (p < 0.05). While there were no significant differences in stereotypic behaviors and salivary cortisol levels during gestation between treatments, the OF sows showed less time spending on the activity at day 105 (p < 0.05). In conclusion, reduced feeding frequency increased BW gain during gestation, decreased activation time, and changed the colostrum composition. This information may contribute to the understanding of the physiological and behavioral change of gestating sows by manipulating feeding frequency.

Replacement of dietary carbohydrate with protein increases fat mass and reduces hepatic triglyceride synthesis and content in female obese Zucker rats

Previous studies have demonstrated both energy restriction (ER) and higher protein (HP), lower carbohydrate (LC) diets downregulate hepatic de novo lipogenesis. Little is known about the independent and combined impact of ER and HP/LC diets on tissue-specific lipid kinetics in leptin receptor-deficient, obese rodents. This study investigated the effects of ER and dietary macronutrient content on body composition; hepatic, subcutaneous adipose tissue (SAT), and visceral AT (VAT) lipid metabolic flux (2 H2 O-labeling); and blood and liver measures of cardiometabolic health in six-week-old female obese Zucker rats (Leprfa+/fa+ ). Animals were randomized to a 10-week feeding intervention: ad libitum (AL)-HC/LP (76% carbohydrate/15% protein), AL-HP/LC (35% protein/56% carbohydrate), ER-HC/LP, or ER-HP/LC. ER groups consumed 60% of the feed consumed by AL. AL gained more fat mass than ER (P-energy = 0.012) and HP/LC gained more fat mass than HC/LP (P-diet = 0.025). Hepatic triglyceride (TG) concentrations (P-interaction = 0.0091) and absolute hepatic TG synthesis (P-interaction = 0.012) were lower in ER-HP/LC versus ER-HC/LP. ER had increased hepatic, SAT, and VAT de novo cholesterol fractional synthesis, absolute hepatic cholesterol synthesis, and serum cholesterol (P-energy≤0.0035). A HP/LC diet, independent of energy intake, led to greater gains in fat mass. A HP/LC diet, in the context of ER, led to reductions in absolute hepatic TG synthesis and TG content. However, ER worsened cholesterol metabolism. Increased adipose tissue TG retention with the HP/LC diet may reflect improved lipid storage capacity and be beneficial in this genetic model of obesity.

The effects of eating frequency on changes in body composition and cardiometabolic health in adults: a systematic review with meta-analysis of randomized trials

BACKGROUND

Eating frequency may affect body weight and cardiometabolic health. Intervention trials and observational studies have both indicated that high- and low-frequency eating can be associated with better health outcomes. There are currently no guidelines to inform how to advise healthy adults about how frequently to consume food or beverages.

AIM

To establish whether restricted- (≤ three meals per day) frequency had a superior effect on markers of cardiometabolic health (primary outcome: weight change) compared to unrestricted-eating (≥ four meals per day) frequency in adults.

METHODS

We searched Medline (Ovid), Embase, CINAHL (EBSCO), Cochrane Central Register of Controlled Trials (CENTRAL), CAB Direct and Web of Science Core Collection electronic databases from inception to 7 June 2022 for clinical trials (randomised parallel or cross-over trials) reporting on the effect of high or low-frequency eating on cardiometabolic health (primary outcome: weight change). Trial interventions had to last for at least two weeks, and had to have been conducted in human adults. Bias was assessed using the Cochrane Risk of Bias tool 2.0. Standardized mean differences (SMD) and 95% confidence intervals were calculated for all outcomes. Certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Seventeen reports covering 16 trials were included in the systematic review. Data from five trials were excluded from meta-analysis due to insufficient reporting. 15 of 16 trials were at high risk of bias. There was very low certainty evidence of no difference between high- and low-frequency eating for weight-change (MD: -0.62 kg, CI95: -2.76 to 1.52 kg, p = 0.57).

CONCLUSIONS

There was no discernible advantage to eating in a high- or low-frequency dietary pattern for cardiometabolic health. We cannot advocate for either restricted- or unrestricted eating frequency to change markers of cardiometabolic health in healthy young to middle-aged adults.

PROTOCOL REGISTRATION

CRD42019137938.

Associations of meal timing, number of eating occasions and night-time fasting duration with incidence of type 2 diabetes in the NutriNet-Santé cohort

BACKGROUND

Food intake plays a pivotal role in regulating circadian rhythms, which modulate glucose and lipid homeostasis. However, studies investigating the association of meal timing and type 2 diabetes (T2D) incidence are lacking. The objective of this study was to investigate the longitudinal associations of meal timing, number of eating occasions and night-time fasting duration with incidence of T2D.

METHODS

In total, 103 312 adults [79% women, mean age at baseline = 42.7 (SD = 14.6)] from the NutriNet-Santé cohort (2009-21) were included. Participants' meal timings and frequency were assessed using repeated 24-h dietary records and averaged from the first 2 years of follow-up (5.7 records/participant). Associations of meal timing, number of eating occasions and night-time fasting duration with incidence of T2D were assessed by using multivariable Cox proportional hazard models adjusted for known risk factors.

RESULTS

During a median follow-up of 7.3 years, 963 new cases of T2D were ascertained. Compared with participants habitually having a first meal before 8AM, those eating after 9AM had a higher incidence of T2D (HR = 1.59, 95% CI 1.30-1.94). Time of last meal was not associated with T2D incidence. Each additional eating episode was associated with a lower incidence of T2D (HR = 0.95, 95% CI 0.90-0.99). Night-time fasting duration was not associated with T2D incidence, except in participants having breakfast before 8AM and fasting for >13 h overnight (HR = 0.47, 95% CI 0.27-0.82).

CONCLUSIONS

In this large prospective study, a later first meal was associated with a higher incidence of T2D. If confirmed in other large-scale studies, an early breakfast should be considered in preventing T2D.

Eating frequency has an inverse correlation with adiposity measures and non-invasive arterial stiffness parameters in healthy adult people

BACKGROUND

Lifestyle modifications have been recommended as an essential treatment approach for cardiovascular diseases. Recent studies have shown that eating frequency (EF) correlates with hypertension and related risk of organ damage. This study aimed to examine critical clinical implications to evaluate the association of EF with arterial stiffness parameters as an early marker of atherosclerosis manifestations.

METHODS

A cross-sectional descriptive study was performed on 658 participants of the PERSIAN Organizational Cohort study in Mashhad, aged 30-70 years. Arterial stiffness was assessed by measurement markers of arteriosclerosis, including arterial age, augmentation index (AIx), augmentation pressure (AP), carotid-femoral pulse wave velocity (Cf-PWV), and central blood pressure. Differences in anthropometric indices, blood indices, and arterial stiffness parameters were evaluated across EF groups.

RESULTS

Our data demonstrate that EF was positively correlated with total daily energy intake, and favourable profiles of adiposity and blood lipids. Subjects with an increased EF, had significantly lower AIx, AP, Arterial Age and Central blood pressure (P for trend<0.001) as compared to Lowest EF and not significant with PWV (P for trend, 0.19). Arterial stiffness was also significantly lower in those with increased EF compared with subjects with low EF. By Linear regression analysis, after adjustment for Confounding factors, except PWV, EF showed the associations with all of the non-invasive arterial stiffness parameters.

CONCLUSION

Increased EF is associated with a lower wave reflection and blood pressure in the central arteries.

Reduced Meal Frequency Decreases Fat Deposition and Improves Feed Efficiency of Growing-Finishing Pigs

An experiment was conducted to examine the effect of meal frequency on growth performance, nutrient digestibility, carcass quality, and lipid metabolism in growing−finishing pigs. Sixty-four Duroc × Landrace × Yorkshire barrows and gilts (26.40 ± 2.10 kg initial body weight) were used in a 112-d experiment in a randomized complete blocked design. The two treatments were the free-access feed group (FA) and the three meals per day group (M3), respectively. The result showed that the average daily feed intake (ADFI) and F: G of the FA group were significantly higher than that in the M3 group during the whole experiment (p < 0.05). Reducing meal frequency also decreased the concentration of triglycerides and urea nitrogen but increased the concentration of insulin and free fatty acids in the blood (p < 0.05). Reducing meal frequency decreased compositions of backfat, belly, and fatty pieces but increased compositions of ham, longissimus muscle, and lean pieces in the carcass (p < 0.05). Greater enzyme activities of ME and FAS and higher mRNA expression of FAS and PPARγ were found in the LM of FA pigs compared with M3 pigs (p < 0.05). In summary, a lower meal frequency improves feed efficiency by regulating lipid metabolism and reducing fat deposition.

Dietary Intake and Nutritional Status in Young and Middle-Aged Adults according to the Meal Frequency from the Korea National Health and Nutritional Survey

Background

Previous studies have shown a close relationship between skipping breakfast and nutritional deficiency. However, the impact of regular eating, including lunch and dinner, has not been studied well. We explored the correlation between regularity and frequency of daily meals and nutritional status.

Methods

We analyzed Korea National Health and Nutrition Examination Surveys between 2016 and 2018. A total of 7,725 adults aged 19–49 years were classified into four groups according to the regularity of meal intake: three-meal regular diet (3MRD), two-meal regular diet, one-meal regular diet, and irregular diet (IRD). Food and nutrient intake was assessed using the 24-hour recall method and estimated by a generalized linear model in complex sample weight variables.

Results

In IRD, there were relatively more females who were not married, lived alone, or reported low levels of education. As subjects ate more meals, more people felt thinner and healthier by themselves. Dietary intake of cereal, vegetables, seaweed, and fiber was directly proportional to the number of regular meals as well as essential components such as water, carbohydrates, protein, fat, and micronutrients. Contrarily, alcohol and beverage consumption was inversely proportional to the number of regular meals. Intake level of legumes, fish, fruits, seasonings, milk, oils, sugars, and cholesterol was consistent regardless of meal frequency.

Conclusion

Our findings suggest that 3MRD showed nutrient adequacy and a healthier profile on body weight, body mass index, waist circumference, blood pressure, serum fasting glucose, total cholesterol, and triglyceride.

Meal occasion, overweight, obesity and central obesity in children and adults: a cross-sectional study based on a nationally representative survey. Colombia, 2015

OBJECTIVE

To establish the association of the number of meals/day with overweight (Ow), obesity (Ob) and central obesity (CO).

DESIGN

Cross-sectional, nationally representative surveys.

SETTING

Colombia.

PARTICIPANTS

A total of 6985 children aged 5-17 years and 7846 adults aged 18-64 years were included.

MAIN OUTCOMES AND MEASURES

According to the WHO, Ow was defined in children as a body mass index (BMI)-for-age Z-score between >1 and ≤2 and in adults as a BMI between ≥25 and <30 (kg/m²). Ob was defined as a Z-score >2 in children and as a BMI ≥30 in adults. CO in children was established by sex and age using cut-off points equivalent to those of adults established by the International Diabetes Federation: ≥90 and ≥80 cm in males and females, respectively. The number of meals/day was estimated with a Food Frequency Questionnaire. Meals/day were grouped into three categories: (reference ≤3, 4 and 5+ meals/day). Crude and adjusted relative prevalence ratios (PRs) and their 95% CIs were calculated. The adjustments included usual energy intake/day and physical activity.

RESULTS

In children, 18.5% had Ow, 6.7% had Ob and 4.0% had CO. The adjusted PRs for five or more meals/day versus three or fewer meals/day were 1.10 (95% CI 0.79 to 1.55) for Ow, 0.95 (95% CI 0.57 to 1.59) for Ob and 1.06 (95% CI 0.72 to 1.55) for CO. In adults, 32.3% had Ow, 13.1% had Ob and 44.8% had CO. The adjusted PRs for five or more meals/day versus three or fewer meals/day were 0.58 (95% CI 0.45 to 0.76) for Ow, 0.51 (95% CI 0.36 to 0.72) for Ob and 0.70 (95% CI 0.54 to 0.92) for CO.

CONCLUSIONS

In children, meals/day were not associated with Ow, Ob or CO. In adults, this inverse relationship exists regardless of energy intake/day, whether physical activity goals are met, sex, age and other potentially confounding sociodemographic and environmental variables.

Prospective study of breakfast frequency and timing and the risk of incident type 2 diabetes in community-dwelling older adults: the Cardiovascular Health Study

BACKGROUND

No evidence-based recommendations regarding optimal breakfast frequency and timing and type 2 diabetes mellitus (T2DM) exist for older adults because of limited studies.

OBJECTIVES

We sought to prospectively assess relations between breakfast frequency and timing and T2DM risk among older adults and determine whether these depended on sex or cardiometabolic risk factors.

METHODS

Weekly breakfast frequency and usual daily breakfast time were assessed by questionnaire at baseline in 3747 older adults (aged ≥ 65 y) from the Cardiovascular Health Study (CHS) who were free of cancer and T2DM and followed for 17.6 y. Multivariable-adjusted hazard ratios (aHRs) with 95% CIs estimated from Cox proportional hazards models were used to quantify associations with T2DM.

RESULTS

Most CHS participants (median age: 74 y; IQR: 71-78 y) consumed breakfast daily (85.5%), and 73% had their first daily eating occasion between 07:00 and 09:00, both of which were associated with higher socioeconomic status, factors that are indicative of a healthier lifestyle, and lower levels of cardiometabolic risk indicators at baseline. During follow-up, 547 T2DM cases were documented. No strong evidence was observed linking breakfast frequency and risk of T2DM. Compared with participants whose breakfast timing (first eating occasion of the day) was 07:00-09:00, those who broke fast after 09:00 had an aHR for T2DM of 0.71 (95% CI: 0.51, 0.99). This association was present in participants with impaired fasting glucose at baseline (aHR: 0.61; 95% CI: 0.39, 0.95) but not in those without (aHR: 0.83; 95% CI: 0.50, 1.38). No associations between eating frequency or timing and T2DM were observed within other prespecified subgroups.

CONCLUSIONS

Eating breakfast daily was not associated with either higher or lower risk of T2DM in this cohort of older adults, whereas a later (after 09:00) daily first eating occasion time was associated with lower T2DM risk in participants with impaired fasting glucose at baseline.This trial was registered at clinicaltrials.gov as NCT00005133.

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

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

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.

Association of dietary patterns, number of daily meals and anthropometric measures in women in age of menopause

OBJECTIVE

To investigate the association of dietary patterns, number of daily meals and anthropometric measures among women in age of menopause.

METHODS

This was a transversal study with 320 women over 50 years old from Caxias do Sul, Brazil. The outcomes were body mass index (BMI) and waist circumference (WC). Multiple linear regression was performed.

RESULTS

Three dietary patterns: regional, fruits and vegetables, and common Brazilian was identified by Principal Component Analysis. After adjustment, higher adoption of the regional dietary pattern was associated with increased BMI (β = 0.56 [CI95% = 0.03-1.08], p = 0.037) and WC (β = 1.28 [CI95% = 0.17-2,55], p = 0.047). The highest number of meals per day (>=5/day) was associated with reduced BMI (β = -1.18 [CI95% = -2.30 to -0.05], p = 0.041) and WC (β = -2.77 [CI95% = -5.41 to -0.13], p = 0.039), and a mid-afternoon snack BMI (β = -2.16 [CI95% = -3.66 to -0.65], p = 0.005) and WC (β = -5.76 [CI95% = -9.29 to -2.23], p = 0,001). The regional dietary pattern was inversely associated with have five or more meals per day (β = -0.51 [CI95% = -0.84 to -0.18], p = 0.002) and have a mid-afternoon snack (β = -0.63 [CI95% = -1.07 to -0.18], p = 0.006). The fruit and vegetables dietary pattern was positively associated with have five or more meals per day (β = 0.35 [CI95% = 0.02-0.69], p = 0.034).

CONCLUSION

The regional dietary pattern has resulted in higher BMI and WC measures and contributes to decreased meals per day, behavior associated with higher anthropometric measures.

The feeding microstructure of male and female mice

The feeding pattern and control of energy intake in mice housed in groups are poorly understood. Here, we determined and quantified the normal feeding microstructure of social male and female mice of the C57BL/6J genetic background fed a chow diet. Mice at 10w, 20w and 30w of age showed the expected increase in lean and fat mass, being the latter more pronounced and variable in males than in females. Under ad libitum conditions, 20w and 30w old females housed in groups showed significantly increased daily energy intake when adjusted to body weight relative to age-matched males. This was the combined result of small increases in energy intake during the nocturnal and diurnal photoperiods of the day without major changes in the circadian pattern of energy intake or spontaneous ambulatory activity. The analysis of the feeding microstructure suggests sex- and age-related contributions of meal size, meal frequency and intermeal interval to the control of energy intake under stable energy balance, but not under negative energy balance imposed by prolonged fasting. During the night, 10-20w old females ate less frequently bigger meals and spent more time eating them resulting in reduced net energy intake relative to age-matched males. In addition, male and female mice at all ages tested significantly shortened the intermeal interval during the first hours of re-feeding in response to fasting without affecting meal size. Further, 20-30w old males lengthened their intermeal interval as re-feeding time increased to reach fed-levels faster than age-matched females. Collectively, our results suggest that the physiological mechanisms controlling meal size (satiation) and the non-eating time spent between meals (satiety) during stable or negative energy balance are regulated in a sex- and age-dependent manner in social mice.

Possible association between eating behaviors and cardiovascular disease in the general population: Analysis of a nationwide epidemiological database

BACKGROUND AND AIMS

Epidemiological evidence on the relationship between eating behaviors, including breakfast skipping, late night dinner, and bedtime snacking, and cardiovascular disease (CVD) events among the general population is scarce. We sought to explore the association of eating behaviors with subsequent CVD using a nationwide epidemiological database.

METHODS AND RESULTS

Medical records of 1,941,125 individuals without prior history of CVD were extracted from the Japan Medical Data Center contracting with more than 60 insurers from multiple regions in Japan, mainly including employed working-age individuals. Skipping breakfast <3 times per week, late night dinner <3 times per week, and bedtime snacking <3 times per week were defined as optimal eating behaviors. Median age was 45 (interquartile range 39-53) years, and 1,138,676 were men. Median follow-up period was 978 (interquartile range 481-1790) days. Among them, 948,805 individuals (48.9%) had optimal eating behaviors, whereas 647,383 individuals (33.4%), 283,017 individuals (14.6%), and 61,920 individuals (3.2%) had single, double, and triple non-optimal eating behaviors, respectively. Individuals with non-optimal eating behaviors were younger and more likely to be men. Obesity and high waist circumference were more commonly observed in those with non-optimal eating behaviors. Multivariable Cox regression analysis showed that, compared with no non-optimal eating behavior, having non-optimal eating behaviors would have higher risk of myocardial infarction, angina pectoris, stroke, and heart failure. However, the dose-response relationship was not clear in the association between the number of non-optimal eating behaviors and incident CVD. Multivariable Cox regression analysis after multiple imputation for missing values also showed the association between non-optimal eating behaviors and incident CVD.

CONCLUSIONS

Using a nationwide epidemiological database, we found a possible relationship between eating behaviors including skipping breakfast, late night dinner, and bedtime snacking, and subsequent cardiovascular events among the general population, suggesting the potential importance of maintaining optimal eating behaviors for the primordial and primary CVD prevention in the general population.

The effect of meal frequency on biochemical cardiometabolic factors: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Although several randomized controlled trials (RCTs) have supported the beneficial effects of higher meal frequency (MF) on cardiometabolic risk factors, the putative effects of higher MF on health remain inconclusive. This study systematically reviewed the evidence from RCTs of the effect of higher compared with lower MF on the blood lipid profile, glucose homeostasis, and adipokines.

METHODS

PubMed, Scopus, ISI Web of Science, and the Cochrane database were searched up to October 2020 to retrieve relevant RCTs. A DerSimonian and Laird random effects model was used to pool mean differences and 95% CI for each outcome. The quality of studies and evidence was assessed through standard methods.

RESULTS

Twenty-one RCTs (686 participants) were included in this meta-analysis. Overall results showed a significant improvement in total cholesterol [weighted mean difference (WMD) = -6.08 mg/dl; 95% CI: -10.68, -1.48; P = 0.01; I² = 88%], and low-density cholesterol (LDL-C) (WMD = -6.82 mg/dl; 95% CI: -10.97, -1.60; P = 0.009; I² = 85.7%), while LDL-C to high-density cholesterol ratio (LDL-C: HDL-C) increased (WMD = 0.22; 95% CI: 0.07, 0.36; P = 0.003; I² = 0.0%) in higher MF vs. lower MF. No significant effects were found on measures of glycemic control, apolipoproteins-A1 and B, or leptin. In subgroup analyses, higher MF significantly reduced serum triglyceride (TG), and increased HDL-C, compared with lower MF in interventions > 12 weeks, and decreased serum TC and LDL-C in healthy participants. A significant reduction in LDL-C also was observed in studies where the same foods given both arms, simply divided into different feeding occasions, and in feeding studies, following higher MF compared to lower MF.

CONCLUSION

Our meta-analysis found that higher, compared with lower MF may improve total cholesterol, and LDL-C. The intervention does not affect measures of glycemic control, apolipoproteins-A1 and B, or leptin. However, the GRADE ratings of low credibility of the currently available evidence highlights the need for more high-quality studies in order to reach a firm conclusion.

Establishment of microcosm biofilm models that reproduce a cariogenic diet intake

Biofilms were developed from human saliva on bovine enamel discs in four experimental conditions to investigate dental caries development: feast and famine (M1), abundance and scarcity (M2), three meals daily (M3), and three meals plus two snacks daily (M4). The main difference between these models was the diet for microbial growth. The evaluations included verifying the pH of the spent culture media and analyzing the enamel discs for demineralization (microhardness and roughness) and biofilms (biomass, viable populations of mutans streptococci, and total microbiota). Two major behaviors were observed: M1 and M2 promoted an acidic environment, while M3 and M4 maintained pH values closer to neutral. The demineralization process was slower in the neutral groups but more pronounced in M3, while a greater increase in microbiota and biomass was observed over time for both neutral groups. Thus, the M3 model was better at mimicking the oral environment that leads to demineralization.

Feeding behavior of growing and finishing pigs fed different dietary threonine levels in a group-phase feeding and individual precision feeding system

Feeding behavior is an important aspect of pig husbandry as it can affect protein deposition (PD) in pigs. A decrease in plasma threonine (Thr) levels may influence feed intake (FI) due to amino acid imbalance. We set out to study whether different Thr inclusion rates of 70%, 85%, 100%, 115%, and 130% of the ideal Thr:lysine (Lys) ratio of 0.65 in two different feeding programs (individual precision feeding and group-phase feeding could affect pig feeding behavior and consequently PD. Two 21-d trials were performed in a 2 × 5 factorial setup (feeding systems × Thr levels) with 110 pigs in the growing phase [25.0 ± 0.8 kg of body weight (BW)] and 110 pigs in the finishing phase (110.0 ± 7.0 kg BW), which correspond to 11 pigs per treatment in each trial. Pigs were housed in the same room and fed using computerized feeding stations. The total lean content was estimated by dual x-ray absorptiometry at the beginning (day 1) and the end (day 21) of the trial. Multivariate exploratory factor analysis was performed to identify related variables. Confirmatory analysis was performed by orthogonal contrasts and Pearson correlation analysis. Graphical analysis showed no difference in feeding patterns between feeding systems during the growing or finishing phase. Pigs exhibited a predominant diurnal feeding, with most meals (73% on average) consumed between 0600 and 1800 h. Exploratory factor analysis indicated that feeding behavior was not related to growth performance or PD in growing or finishing pigs. Changes in feeding behavior were observed during the growing phase, where increasing dietary Thr resulted in a linear increase in the FI rate (P < 0.05). During the finishing phase, the duration of the meal and FI rate increased linearly as dietary Thr increased in the diet (P < 0.05). These changes in feeding behavior are, however, correlated to BW. In conclusion, the exploratory factor analysis indicated that feeding behavior had no correlation with growth performance or protein and lipid deposition in growing or finishing pigs. Dietary Thr levels and feeding systems had no direct effect on FI.

Prospective Study of Skipping Meals to Lose Weight as a Predictor of Incident Type 2 Diabetes With Potential Modification by Cardiometabolic Risk Factors: The Canadian 1995 Nova Scotia Health Survey

BACKGROUND

Skipping meals is an increasingly common practice to lose weight among North American adults. However, the long-term effect of this practice on incident type 2 diabetes mellitus (T2DM) remains unknown. We assessed whether skipping meals to lose weight is associated with T2DM risk and whether this association is modified by cardiometabolic risk factors.

METHODS

Skipping meals to lose weight was assessed by questionnaire in 2,288 adults from the 1995 Nova Scotia Health Survey and was linked to administrative health databases to determine T2DM incidence in the following 23 years. Multivariable-adjusted Cox proportional hazards models estimated hazard ratios (aHRs) and 95% confidence intervals (CIs) for T2DM.

RESULTS

During follow up, 378 T2DM cases were diagnosed. Compared with participants who did not skip meals to lose weight, those who did (2.2%) had a 125% higher risk of T2DM (aHR, 2.25; 95% CI, 1.31 to 3.86). This association was no longer present after further adjustment for baseline body mass index (BMI) (aHR, 1.66; 95% CI, 0.96 to 2.85). Skipping meals to lose weight was associated with T2DM among participants who were men (n=1,135; aHR, 2.09; 95% CI, 1.09 to 4.02) or had a BMI <30 kg/m² (n=1,676; aHR, 2.64, 95% CI, 1.15 to 6.06), elevated cholesterol (n=1,146; aHR, 2.11; 95% CI, 1.06 to 4.22), high blood pressure (n=1,133; aHR, 2.10; 95% CI, 1.10 to 4.01) and restless sleep (n=1,186; aHR, 2.19; 95% CI, 1.13 to 4.25), but not among women, those with a BMI of ≥30 kg/m² and those without elevated cholesterol, high blood pressure or restless sleep.

CONCLUSIONS

Skipping meals to lose weight may be a predictive modifiable risk factor for developing T2DM over time, potentially working in connection with other T2DM risk factors.

Major dietary patterns and predicted cardiovascular disease risk in an Iranian adult population

BACKGROUND

Limited data are available on the association of major dietary patterns and predicted risk of cardiovascular disease (CVD) using the Framingham Risk Score (FRS).

AIM

To investigate the association between major dietary patterns and the predicted 10-year CVD risk in an Iranian population.

METHODS

This cross-sectional study was conducted on 522 apparently healthy adults referred to health centers in Tehran. Usual dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. The association between dietary patterns and the predicted risk of development of CVD was evaluated using linear multiple regression. Principal component analysis was used to identify major dietary patterns.

RESULTS

In total, 41% of the men (n = 95) and 46% of women (n = 134) were in the low risk (<10%) and 6% of men (n = 14) and 1% of women (n = 3) were in the high risk (> 20%) category of the FRS. A significant decrease was found for body mass index (p < 0.001), systolic blood pressure (SBP) (p = 0.003), diastolic blood pressure (p = 0.005), and triglyceride (p = 0.02) in the higher tertile of healthy dietary pattern. Adherence to an unhealthy dietary pattern was associated with a significant increase in body weight (p = 0.03) and a significant decrease in high-density lipoprotein cholesterol (p < 0.001). The healthy dietary pattern score was negatively associated with SBP (p = 0.04) and FRS (p < 0.001).

CONCLUSION

Although we observed improvements in CVD risk factors with greater adherence to healthy dietary patterns, there was no association between identified dietary patterns and the predicted risk of 10-year CVD.

Associations of Number of Daily Eating Occasions with Type 2 Diabetes Risk in the Women's Health Initiative Dietary Modification Trial

BACKGROUND

Over 23 million Americans have type 2 diabetes (T2D). Eating habits such as breakfast consumption, time-restricted eating, and limiting daily eating occasions have been explored as behaviors for reducing T2D risk, but prior evidence is inconclusive.

OBJECTIVES

Our objectives were to examine associations between number of daily eating occasions and T2D risk in the Women's Health Initiative Dietary Modification Trial (WHI-DM) and whether associations vary by BMI, age, or race/ethnicity.

METHODS

Participants were postmenopausal women in the WHI-DM who comprised a 4.6% subsample completing 24-h dietary recalls (24HRs) at years 3 and 6 as part of trial adherence activities (n = 2159). Numbers of eating occasions per day were obtained from the year 3 24HRs, and participants were grouped into approximate tertiles as 1-3 (n = 795), 4 (n = 713), and ≥5 (n = 651) daily eating occasions as the exposure. Incident diabetes was self-reported on semiannual questionnaires as the outcome.

RESULTS

Approximately 15% (15.4%, n = 332) of the WHI-DM 24HR cohort reported incident diabetes at follow-up. Cox proportional hazards regression tested associations of eating occasions with T2D adjusted for neighborhood socioeconomic status, BMI, waist circumference, race/ethnicity, family history of T2D, recreational physical activity, Healthy Eating Index-2005, 24HR energy intake, and WHI-DM arm. Compared with women reporting 1-3 meals/d, those consuming 4 meals/d had a T2D HR = 1.38 (95% CI: 1.03, 1.84) without further increases in risk for ≥5 meals/d. In stratified analyses, associations for 4 meals/d compared with 1-3 meals/d were stronger in women with BMI <30.0 kg/m2 (HR = 1.55; 95% CI: 1.00, 2.39) and women aged ≥60 (HR = 1.61; 95% CI: 1.11, 2.33).

CONCLUSIONS

Four meals per day compared with 1-3 meals/d was associated with increased risk of T2D in postmenopausal women, but no dose-response effect was observed for additional eating occasions. Further studies are needed to understand eating occasions in relation to T2D risk.

The Effects of Meal Timing and Frequency, Caloric Restriction, and Fasting on Cardiovascular Health: an Overview

Cardiovascular disease (CVD), which is the leading cause of death worldwide, is strongly affected by diet. Diet can affect CVD directly by modulating the composition of vascular plaques, and indirectly by affecting the rate of aging. This review summarizes research on the relationships of fasting, meal timing, and meal frequency with CVD incidence and progression. Relevant basic research studies, epidemiological studies, and clinical studies are highlighted. In particular, we discuss both intermittent and periodic fasting interventions with the potential to prevent and treat CVD.

New Insight into Diabetes Management: From Glycemic Index to Dietary Insulin Index

BACKGROUND

Despite efforts to control hyperglycemia, diabetes management is still challenging. This may be due to focusing on reducing hyperglycemia and neglecting the importance of hyperinsulinemia; while insulin resistance and resultant hyperinsulinemia preceded diabetes onset and may contribute to disease pathogenesis.

OBJECTIVE

The present narrative review attempts to provide a new insight into the management of diabetes by exploring different aspects of glycemic index and dietary insulin index.

RESULTS

The current data available on this topic is limited and heterogeneous. Conventional diet therapy for diabetes management is based on reducing postprandial glycemia through carbohydrate counting, choosing foods with low-glycemic index and low-glycemic load. Since these indicators are only reliant on the carbohydrate content of foods and do not consider the effects of protein and fat on the stimulation of insulin secretion, they cannot provide a comprehensive approach to determine the insulin requirements.

CONCLUSION

Selecting foods based on carbohydrate counting, glycemic index or glycemic load are common guides to control glycemia in diabetic patients, but neglect the insulin response, thus leading to failure in diabetes management. Therefore, paying attention to insulinemic response along with glycemic response seems to be more effective in managing diabetes.

Meal timing, meal frequency, and breakfast skipping in adult individuals with type 1 diabetes - associations with glycaemic control

We assessed meal timing, meal frequency, and breakfast consumption habits of adult individuals with type 1 diabetes (n = 1007) taking part in the Finnish Diabetic Nephropathy Study, and studied whether they are associated with glycaemic control. Data on dietary intake and blood glucose measurements were retrieved from food records. HbA_1c was measured at the study visit. In the whole sample, four peaks of energy intake emerged. Energy intake was the greatest in the evening, followed by midday. Altogether 7% of the participants reported no energy intake between 05:00 and 09:59 (breakfast skippers). While breakfast skippers reported lower number of meals, no difference was observed in the total energy intake between those eating and omitting breakfast. In a multivariable model, skipping breakfast was associated with higher mean blood glucose concentrations and lower odds of good glycaemic control. A median of 6 daily meals was reported. Adjusted for confounders, the number of meals was negatively associated with HbA_1c, and the mean of the blood glucose measurements, but positively associated with the variability of these measurements. Our observations support the habit of a regular meal pattern, including consumption of breakfast and multiple smaller meals for good glycaemic control in adults with type 1 diabetes. However, an increase in the blood glucose variability may additionally be expected with an increase in the number of meals eaten.

Higher eating frequency, but not skipping breakfast, is associated with higher odds of abdominal obesity in adults living in Puerto Rico

Puerto Ricans have a high prevalence of obesity, yet little information is available regarding its association with eating patterns in this population. We hypothesized that higher eating frequency and skipping breakfast would be associated with increased odds of abdominal obesity among adults living in Puerto Rico (PR). In a cross-sectional study of adults living in PR aged 30-75 years (N = 310), participants reported their frequency of eating meals per day including snacks and breakfast. Trained interviewers measured waist (WC) and hip circumferences. We calculated the waist-to-hip ratio (WHR) dividing the waist by the hip measurement. Abdominal obesity was defined as either high WC (men ≥94 cm; women ≥80 cm) or high WHR (men ≥0.90; women ≥0.85). We used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) to assess the association of eating frequency (≤1.5; 1.5-3; ≥3 times/day) and breakfast consumption (vs none) with abdominal obesity. Models were adjusted for age, sex, income, smoking, physical activity, TV watching, energy intake, diet quality, and eating frequency (only for breakfast consumption). Most participants consumed breakfast (70%), ate 1.5-3 times/d (47%), and had high WC (75%) and WHR (77%). Participants who ate 1.5-3 (OR: 2.75, 95% CI: 1.23-6.15) and ≥3 times/day (OR: 2.88; 95% CI: 1.14-7.31) were more likely to have high WC compared with participants who ate ≤1.5 times/d (P trend = .04). Breakfast consumption was not associated with abdominal obesity. In conclusion, higher eating frequency, but not skipping breakfast, is associated with abdominal obesity among adults in PR. Consuming less frequent meals may help prevent abdominal obesity in this population.

Refined carbohydrates, phenotypic plasticity and the obesity epidemic

The major change in the United States and European diets associated with the increased rates of obesity was an increased consumption of refined carbohydrates. A feature of refined carbohydrates is their predisposition to cause increased fluctuations in plasma insulin and glucose levels and postprandial reactive hypoglycaemia. As the central nervous system is dependent on a stable supply of glucose this threatens the central nervous system functioning and these fluctuations also have a negative impact on the cardiovascular system. Phenotypic plasticity enables organisms to use adaptive phenotypes already in existence such as the increased insulin resistance and increased adiposity associated with pregnancy or the insulin resistance associated with infection, trauma and burns or to evolve new phenotypes to adapt to variations in the environment. This paper explores the evidence that increased insulin resistance that is commonly associated with increased adiposity possibly because of shared locations on the genome is a phenotypic plastic adaptation to the increased consumption of refined carbohydrates and their predisposition to cause increased fluctuations in plasma insulin and plasma glucose and post-prandial reactive hypoglycaemia both of which have negative impacts on the metabolism. Obesity, that is a relatively stable state of increased adiposity and insulin resistance has adaptive and defensive features to these fluctuations in plasma insulin and glucose in that metabolic disorders associated with refined carbohydrate consumption are often mitigated and modified as exemplified by the obesity paradox.

Dinner consumption and cardiovascular disease risk factors among a nationally representative sample of Iranian adolescents: the CASPIAN-III Study

Introduction: This cross-sectional study aimed to assess the association between cardiovascular disease (CVD) risk factors and dinner consumption in a nationally representative sample of Iranian adolescents.

Methods: The present study was conducted on 5642 adolescents aged 10-18 years old in 27 provinces in Iran. The subjects were included applying by multistage random cluster sampling. Participants who ate ≥5 dinners during a week were considered as a dinner consumer.

Results: Among 5642 subjects, 1412 (25%) did not consume dinner. Dinner consumers were less likely to be overweight or obese (P < 0.001) and abdominally obese (P < 0.001) as well as to have an abnormal level of HDL-C (P = 0.02). Dinner skipper youths had a higher risk for overweight or obesity (odds ratio [OR]: 1.62; 95% CI: 1.39-1.89) and abdominal obesity (OR: 1.59; 95% CI: 1.36-1.85) which remained significant after adjusting confounding factors (P <0001). No relationship was observed between dinner consumption and the rest of the CVD risk factors, neither in crude nor in adjusted models. A higher proportion of dinner-consumer adolescents had no CVD risk factors in comparison to dinner-skipper subjects (31.1% vs. 28%).

Conclusion: Eating dinner might be inversely associated with some CVD risk factors among Iranian adolescents. Further prospective studies will need to prove this theory.

Snacking in nutrition and health

Many studies suggest that distributing energy and nutrient intake across 4-5 eating occasions/day (rather than across three standard meals) could favourably affect human health. The inclusion of 1-2 snacks in the daily pattern alleviates the potential digestive and metabolic overload caused by fewer heavier meals and might contribute to meet recommendations for food groups (e.g. fruits, dairy) and nutrients like fibre and vitamins. The snack composition should be evaluated taking into account the whole day's diet. In early and late ages, and for specific population groups, snacking may need to follow particular characteristics in order to be optimal, both in terms of composition and timing. This document, which is the result of a collaboration of experts across several fields of research, intends to provide a review of the current scientific literature on meal frequency and health, highlighting the beneficial effects of correct snack consumption across the human lifespan.

Eating frequency is inversely associated with BMI, waist circumference and the proportion of body fat in Korean adults when diet quality is high, but not when it is low: analysis of the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

The role of eating frequency (EF) in obesity development has been debated, and few studies have investigated Asian populations. Diet quality might affect the association between EF and obesity. Therefore, we investigated the association between EF and obesity indicators in a representative sample of Korean adults with consideration to diet quality. This cross-sectional study used data of 6951 participants aged 19-93 years (male 49·8 %, female 50·2 %) from the Fourth Korean National Health and Nutrition Examination Survey. EF was assessed using a questionnaire, and diet quality was defined as mean adequacy ratio (MAR). To explore the association between EF and obesity indicators, we used multiple linear regression analyses with and without interaction terms between diet quality and EF. EF was inversely associated with each obesity indicator, including body fat percentage (BF%), BMI and waist circumference (WC), showing a significant linear trend (P<0·001 for BF%, WC and BMI). In addition, the association between EF and each obesity indicator was significantly altered according to diet quality (P value of the interaction term EF×diet quality=0·008 in the regression model for BF%, <0·001 for BMI and 0·043 for WC). In the stratified analyses according to diet quality, EF had a significant inverse association with BF%, WC and BMI in the high diet quality groups, but not in the low diet quality groups. This study suggests that EF is inversely associated with the obesity indicators when diet quality is high, but not when it is low in Korean adults.

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.

Consuming Carbohydrates after Meat or Vegetables Lowers Postprandial Excursions of Glucose and Insulin in Nondiabetic Subjects

We aimed to examine the effects of variable timing of carbohydrate intake on postprandial glucose and insulin excursion in a diet with the same levels of energy and balance of three major nutrients. The study subjects included 8 healthy individuals, mean age 20.0±1.2 y (4 males and 4 females; mean age, 19.1±0.7 and 20.8±0.9 y, respectively), without a family history of diabetes. They consumed a test meal consisting of three separate plates of rice, vegetables, and meat after an overnight fast. The subjects consumed the three plates in different orders on three different days; the subsequent changes in glucose and insulin levels were measured over a 120-min period. The participants who consumed rice at the end showed a significantly lower increase in glucose and insulin levels after 30 min of consumption than that shown by participants who consumed rice first. The areas under the curves for both glucose and insulin responses over 120 min were the least when rice was consumed last, whereas they were the greatest when rice was consumed first. These findings suggested that consuming carbohydrates at the end of a meal is associated with lower postprandial excursions of glucose and insulin. In conclusion, consuming carbohydrates last following vegetables and meat protects against postprandial excursions of glucose and insulin levels.

Diet, exercise and weight loss and dyslipidaemia

There is a large amount of controversy relating dietary fat intake and coronary artery disease. It has been strongly suggested that saturated fat is not harmful and that polyunsaturated fat is either not beneficial or even harmful. Given that dietary lipids and fibre can influence serum lipids which are strongly linked to the risk of coronary artery disease I have reviewed recent evidence linking diet and serum lipids to confirm a diet-heart disease link. Over 84 studies have been included in a recent meta-analysis and meta-regression which examined the effects of changes in fat type on lipid levels. An absolute 1% reduction in saturated fat or trans fat intake as a percentage of energy with replacement by n-6 polyunsaturated fat would lead to a reduction in low density lipoprotein (LDL) cholesterol of 0.05 mmol/L. In most Western countries the difference in intake between the highest quintile and the lowest quintile of saturated fat is about 7%, so moving from the highest to the lowest quintile should lower LDL cholesterol by 0.35 mmol/L or about 10%. This change should lower cardiovascular disease rates by at least 10%. Replacing this amount of saturated fat with carbohydrate of average quality would lower LDL cholesterol by 0.21 mmol/L and increase fasting triglyceride by 0.17 mmol/L. This combination of effects would have a neutral effect on cardiovascular disease rates. However, replacement of trans fat appears to reduce disease rates and total mortality. Substituting low glycaemic index carbohydrates for high glycaemic index carbohydrates will lower triglyceride by 15-25% and reduce cardiovascular risk. Large doses of fish oil will lower triglyceride with a mean lowering of 0.45 mmol/L for a 3.5 g/day amount. Large doses of soluble fibre (3.5-7.0 g/day) lower LDL cholesterol by 0.2-0.35 mmol/L with Konjac glucomannan being the most effective per gram. Plant sterols or stanols lower LDL cholesterol by about 10% for a 2 g/day dose, while exercise and weight loss lower cardiovascular risk predominantly by lowering fasting triglyceride. In conclusion, diet lowers LDL cholesterol and triglyceride and dietary changes should be ultimately linked to a reduced risk of heart disease.

Longitudinal association between eating frequency and hemoglobin A1c and serum lipids in diabetes in the SEARCH for Diabetes in Youth study

BACKGROUND

Few studies have evaluated the prospective association of eating frequency with HbA1c levels and cardiovascular disease risk markers among youth with diabetes.

OBJECTIVE

To examine the 5-year longitudinal association of eating frequency with HbA1c and serum lipid levels among youth with type 1 diabetes (T1D) or type 2 diabetes (T2D).

METHODS

One-thousand and forty-nine youth (≥10-year old) with incident T1D (n = 821) or T2D (n = 228) who participated in the SEARCH for Diabetes in Youth study were included. Eating frequency (≤3, 4-5, or 6-10 times/d) measured at baseline and follow-up visits was related to HbA1c and serum lipid levels measured repeatedly over 5 years.

RESULTS

Increased eating frequency was associated with larger increases in HbA1c among youth T1D. For example, for youth with T1D who ate ≤3 times/d at the outset and ate 6-10 times/d 5 years later, the longitudinal model predicted greater absolute increases in HbA1c (2.77%); whereas for youth with T1D who ate 6-10 times/d at the outset and ate ≤3 times/d 5 years later, the model predicted lesser absolute increases in HbA1c (1.33%). Eating frequency was not associated with changes in serum lipid levels among youth with T1D or T2D.

CONCLUSIONS

Youth with T1D who increased their eating frequency vs those who decreased it had larger increases in HbA1c over 5 years.

The benefits of defining "snacks"

Whether eating a "snack" is considered a beneficial or detrimental behavior is largely based on how "snack" is defined. The term "snack food" tends to connote energy-dense, nutrient-poor foods high in nutrients to limit (sugar, sodium, and/or saturated fat) like cakes, cookies, chips and other salty snacks, and sugar-sweetened beverages. Eating a "snack food" is often conflated with eating a "snack," however, leading to an overall perception of snacks as a dietary negative. Yet the term "snack" can also refer simply to an eating occasion outside of breakfast, lunch, or dinner. With this definition, the evidence to support health benefits or detriments to eating a "snack" remains unclear, in part because relatively few well-designed studies that specifically focus on the impact of eating frequency on health have been conducted. Despite these inconsistencies and research gaps, in much of the nutrition literature, "snacking" is still referred to as detrimental to health. As discussed in this review, however, there are multiple factors that influence the health impacts of snacking, including the definition of "snack" itself, the motivation to snack, body mass index of snack eaters, and the food selected as a snack. Without a definition of "snack" and a body of research using methodologically rigorous protocols, determining the health impact of eating a "snack" will continue to elude the nutrition research community and prevent the development of evidence-based policies about snacking that support public health.

Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial

BACKGROUND/OBJECTIVES

The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140-199mg/dL at 120min (IGT-A) or PG levels 140-199mg/dL at 120min and >200mg/dL at 30/60/90min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D).

SUBJECTS/METHODS

In this randomized crossover study, subjects with IGT-A (n=15, BMI: 32.4±5.2kg/m²), IGT-B (n=20, BMI: 32.5±5kg/m²) or T2D (n=12, BMI: 32.2±5.2kg/m²) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period.

RESULTS

Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120min post-OGTT decreased with 6 vs 3 meals (P<0.001 vs P=0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P<0.05). There were no differences in HOMA-IR or plasma lipids between interventions.

CONCLUSION

Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.

Complex interactions of circadian rhythms, eating behaviors, and the gastrointestinal microbiota and their potential impact on health

Human health is intricately intertwined with the composition and function of the trillions of microorganisms that make up the gastrointestinal (GI) microbiome. The GI microbiome is essentially a microbial organ that provides metabolic, immunologic, and protective functions for the host. Habitual diet, changes in macronutrient composition, and consumption of nondigestible dietary fibers have all been shown to impact the human GI microbiome. Intriguingly, the impact of diet on the microbiome may be related not only to what humans eat but also to the timing of food consumption. Emerging preclinical research suggests that gut microbes experience diurnal rhythms, and the health effects of eating patterns, including time-restricted feeding and meal frequency, may be related to the GI microbiome. Herein, the complex connections among circadian rhythms, eating behaviors, the GI microbiome, and health are reviewed, highlighting the need for additional translational research in this area.

A randomized, controlled, crossover study of appetite-related sensations after consuming snacks made from buckwheat

With the rising incidence of overweight and obesity in developed countries, there is an interest in developing food products that may aid in satiety and reduce energy intake. Buckwheat (Fagopyrum esculentum) is a gluten-free edible seed that has been previously shown to induce changes in postprandial concentrations of satiety hormones; however, subjective measures of appetite-related sensations and objective measures of energy intake at subsequent meals following buckwheat consumption have not been measured. Thirty-eight healthy adults were recruited to participate in a randomized, controlled, crossover trial with the main objective to determine if consuming snacks made from buckwheat would increase satiety and reduce energy intake compared with snacks comparable in serving size, physical characteristics, and nutrient composition. Water was included as a no-kilocalorie control. Participants received each of the treatments once separated by at least 7 days. Appetite related sensations were assessed using visual analog scales at fasting and after consuming the snack at 30-min intervals for 180 min. Lunch was provided at the clinic and the amount of food consumed was weighed. Participants recorded food intake for the rest of the day. Consuming buckwheat groats (32 g serving; 141 kcal) or pita bread made from buckwheat flour (50 g serving; 135 kcal) was not associated with changes in appetite related sensations or energy consumption compared with reference snack products made from corn or rice flour. Sensory questionnaires revealed that snacks made from buckwheat were liked to a similar degree or more as reference snack products, which shows commercial promise for developing buckwheat-containing snacks.

Time of day and eating behaviors are associated with the composition and function of the human gastrointestinal microbiota

Background: Preclinical research has shown that the gastrointestinal microbiota exhibits circadian rhythms and that the timing of food consumption can affect the composition and function of gut microbes. However, there is a dearth of knowledge on these relations in humans.Objective: We aimed to determine whether human gastrointestinal microbes and bacterial metabolites were associated with time of day or behavioral factors, including eating frequency, percentage of energy consumed early in the day, and overnight-fast duration.Design: We analyzed 77 fecal samples collected from 28 healthy men and women. Fecal DNA was extracted and sequenced to determine the relative abundances of bacterial operational taxonomic units (OTUs). Gas chromatography-mass spectroscopy was used to assess short-chain fatty acid concentrations. Eating frequency, percentage of energy consumed before 1400, and overnight-fast duration were determined from dietary records. Data were analyzed by linear mixed models or generalized linear mixed models, which controlled for fiber intake, sex, age, body mass index, and repeated sampling within each participant. Each OTU and metabolite were tested as the outcome in a separate model.Results: Acetate, propionate, and butyrate concentrations decreased throughout the day (P = 0.006, 0.04, and 0.002, respectively). Thirty-five percent of bacterial OTUs were associated with time. In addition, relations were observed between gut microbes and eating behaviors, including eating frequency, early energy consumption, and overnight-fast duration.Conclusions: These results indicate that the human gastrointestinal microbiota composition and function vary throughout the day, which may be related to the circadian biology of the human body, the microbial community itself, or human eating behaviors. Behavioral factors, including timing of eating and overnight-fast duration, were also predictive of bacterial abundances. Longitudinal intervention studies are needed to determine causality of these biological and behavioral relations. This trial was registered at clinicaltrials.gov as NCT01925560.

Development and validation of the self-administered Falun health instrument (SAFHI) using data from health promoted workplaces in Sweden

AIM

The aim of this study was to develop and to validate the self-administered Falun health instrument. An additional aim was to test its applicability in measuring people's lifestyles linked to health.

METHODS

In 2002, an instrument was constructed containing questions regarding the hazardous use of alcohol, tobacco, unhealthy diets and insufficient physical activity. A pilot study using the instrument was assessed between 2002 and 2006. In Sweden, it was further expanded and tested during the years 2004-2014 among a total of 1295 people.

RESULTS

Face validity was evaluated among colleagues and experts for clarity and completeness resulting in minor adjustments of some questions. With the test-retest method, the self-administered Falun health questionnaire showed a positive and high reproducibility and high compliance. Cronbach's alpha showed a high level of consistency (average 0.86). Factor analysis demonstrated the choice of questions correlated highly to the measured lifestyle.

CONCLUSIONS

This study showed that the self-administered Falun health questionnaire is a valid and reliable instrument, useful for detecting individuals at risk of developing diseases that are related to individual choice of lifestyle.

Disparities in Snacking Trends in US Adults over a 35 Year Period from 1977 to 2012

BACKGROUND

Previous studies have indicated that snacking is contributing to increased calories in the American diet, and that the contribution of snacks to energy intake has increased in recent decades.

OBJECTIVE

The objective was to examine trends in the energy intake deriving from snacks and food sources of snacks for US adults over 35 years from 1977 to 2012, and whether these trends differ across sociodemographic groups.

METHODS

Participants included 74,291 US adults aged ≥19 years who participated in the 1977-1978 Nationwide Food Consumption Survey (NFCS); the 1989-1991 Continuing Survey of Food Intake by Individuals (CSFII), the 1994-1996 CSFII, the 1997-1998 CSFII, National Health and Nutrition Examination Survey (NHANES) 2003-2004, NHANES 2005-2006, NHANES 2009-2010 and NHANES 2011-2012; all surveys are a stratified random sample of the total civilian, non-institutionalized US population. Overall patterns of snacking, trends in energy intake from snacking, trends in snacking food and beverage sources and energy intake from snacks across racial/ethnic, age, education and income groups were examined.

RESULTS

For all US adults there was a significant increase in per capita energy intake from snacks from 1977 to 2012 (p < 0.01). Non-Hispanic blacks had the highest snacking energy intake from sugar-sweetened beverages (SSBs) in each year (p < 0.01 for all), with a peak intake in 2003-2006 of 76 kcal per capita per day. Intake of salty snacks increased in all groups between 1977 and 2012, with non-Hispanic blacks having the highest intake in 2009-2012 (p < 0.01). No significant differences were found between income or education groups.

CONCLUSIONS

Results show that snacking remains a significant component of the US diet and the foods consumed at these snacks (SSBs, desserts and sweets and salty snacks) are not the types of foods recommended by the US dietary guidelines. Our finding that non-Hispanic blacks are consuming a higher proportion of SSBs and salty snacks than other groups, and showing the largest increase in energy intake deriving from snacks overall over the past 35 years, is indeed concerning.

Eating frequency and weight and body composition: a systematic review of observational studies

Objective

The present review aimed to examine the association of eating frequency with body weight or body composition in adults of both sexes.

Design

PubMed, EMBASE and Scopus databases were searched. PRISMA and MOOSE protocols were followed. Observational studies published up to August 2016 were included. The methodological quality of the studies was assessed with the Downs and Black checklist.

Setting

A systematic review of the literature.

Subjects

Adults (n 136 052); the majority of studies were developed in the USA and Europe.

Results

Thirty-one articles were included in the review: two prospective and twenty-nine cross-sectional studies. Thirteen per cent of the studies received quality scores above 80 %. The assessment of eating frequency and body composition or body weight varied widely across the studies. Potential confounders were included in 73 % of the studies. Fourteen studies reported an inverse association between eating frequency and body weight or body composition, and seven studies found a positive association. The majority of studies applied multiple analyses adjusted for potential confounders, such as sex, age, education, income, smoking, physical activity and alcohol intake. Six studies took into account under-reporting of eating frequency and/or energy intake in the analysis, and one investigated the mediation effect of energy intake.

Conclusions

There is not sufficient evidence confirming the association between eating frequency and body weight or body composition when misreporting bias is taken into account. However, in men, a potential protective effect of high eating frequency was observed on BMI and visceral obesity.

Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association

Eating patterns are increasingly varied. Typical breakfast, lunch, and dinner meals are difficult to distinguish because skipping meals and snacking have become more prevalent. Such eating styles can have various effects on cardiometabolic health markers, namely obesity, lipid profile, insulin resistance, and blood pressure. In this statement, we review the cardiometabolic health effects of specific eating patterns: skipping breakfast, intermittent fasting, meal frequency (number of daily eating occasions), and timing of eating occasions. Furthermore, we propose definitions for meals, snacks, and eating occasions for use in research. Finally, data suggest that irregular eating patterns appear less favorable for achieving a healthy cardiometabolic profile. Intentional eating with mindful attention to the timing and frequency of eating occasions could lead to healthier lifestyle and cardiometabolic risk factor management.

Randomized Trial Testing the Effects of Eating Frequency on Two Hormonal Biomarkers of Metabolism and Energy Balance

BACKGROUND

Eating frequency (EF) may influence obesity-related disease risk by attenuating postprandial fluctuations in hormones involved in metabolism, appetite regulation, and inflammation.

MATERIALS/METHODS

This randomized crossover intervention trial tested the effects of EF on fasting plasma insulin-like growth factor-I (IGF-1) and leptin. Fifteen subjects (4 males, 11 females) completed two eucaloric intervention phases lasting 21 days each: low EF ("low-EF"; 3 eating occasions/day) and high EF ("high-EF"; 8 eating occasions/day). Subjects were free-living and consumed their own meals using individualized structured meal plans with instruction from study staff. Subjects completed fasting blood draws and anthropometry on the first and last day of each study phase. The generalized estimated equations modification of linear regression tested the intervention effect on fasting serum IGF-1 and leptin.

RESULTS

Mean (± SD) age was 28.5 ± 8.70 years, and mean (± SD) Body Mass Index was 23.3 (3.4) kg/m². We found lower mean serum IGF-1 following the high-EF condition compared to the low-EF condition (P < 0.001). There was no association between EF and plasma leptin (P = 0.83).

CONCLUSION

These results suggest that increased EF may lower serum IGF-1, which is a hormonal biomarker linked to increased risk of breast, prostate, and colorectal cancer.

The Heterogeneity of Obesity: Fitting Treatments To Individuals - Republished Article

Body weight is regulated by a complex interaction of biological, behavioral, and cultural factors. The population as a whole is at risk for obesity because of increased intake of dietary fat, the consumption of calories in fewer meals per day, striking accessibility to palatable foods, and decreased physical activity. This risk may become a reality in individuals with certain biological predispositions (genetic tendency, low metabolic rate, increased fat cell number), specific eating patterns, and susceptibility to the extreme cultural pressure to be lean. These factors must be considered in establishing goals for treatment, which fall into medical and psychosocial categories. This includes defining a "reasonable" as opposed to "ideal" weight. A three-stage process is proposed for identifying the best treatment for an individual. This involves a classification decision, a stepped care decision, and then a matching decision. Criteria are provided for a comprehensive assessment of the overweight individual, and treatment options are reviewed for programs of varying intensity, cost, and risk.

Dietary Factors in Reducing Risk of Cardiovascular Diseases

Diet influences many modifiable risk factors for cardiovascular diseases (CVDs). Considering this, moderation of total dietary fat, particularly trans and saturated fats, as well as cholesterol is recommended. Dietary fats should come mainly from plants and fatty fish, providing monounsaturated and polyunsaturated (including omega-3) fatty acids. Carbohydrate sources to emphasize include whole grains, legumes, vegetables, fruits, and other fiber-rich sources, rather than sugars. Although vitamins such as E, C, and some B vitamins are associated with reduced CVD risk, data do not support the use of supplements, but foods rich in these nutrients are advocated. Dietary minerals such as potassium, magnesium, and calcium may be beneficial to heart health, while reduction of dietary sodium decreases risk of hypertension. A large variety of phytonutrients are also associated with reduced CVD risk. Other dietary factors receiving research attention regarding CVD risk. Other dietary factors receiving research attention regarding CVD risk include caffeine, alcobol, and meal frequency, although more work is needed in these areas. In contrast, data are quite robust to support the importance of healthy body weight management in cardiovascular health. In general, diets based on a variety of less processed foods, mainly of plant origin, in the context of an active lifestyle, are conducive to heart health.