Chrono-nutrition is an emerging field that examines how the frequency and timing of meals impact health. Previous research shows inconsistency in the relationship between chrono-nutritional components and cardiometabolic health. We investigated cross-sectional associations between these components and cardiometabolic health in 825 Iranian adults aged 20–59 years. Dietary data, including the number of eating occasions, meal timing and meal irregularity of energy intake, were collected using three 24-h dietary recalls. Anthropometric measurements, blood pressure and laboratory tests (fasting plasma glucose, lipid profile, insulin, uric acid and C-reactive protein) were conducted. Insulin resistance and sensitivity (homeostatic model assessment for insulin resistance, homeostatic model assessment for insulin sensitivity), the TAG-glucose, the lipid accommodation product and BMI were calculated. The demographic and morning-evening questionnaire was completed. General linear regression was used to assess associations between chrono-nutritional components and outcomes. Interactions with age and BMI were examined in all associations. Chrono-nutrition components were not significantly related to cardiometabolic risk factors in the total population. However, a lower number of eating occasions was associated with an increased LDL-cholesterol:HDL-cholesterol ratio (β (95 % CI): 0·26 (0·06, 0·48)) among overweight and obese participants. Additionally, less irregularity in breakfast energy intake was associated with a lower total cholesterol:HDL-cholesterol ratio (–0·37 (–0·95, –0·18)) and a lower LDL-cholesterol:HDL-cholesterol ratio (–0·32 (–0·79, –0·13)) among participants with a normal BMI (all P< 0·05). The study concluded that more frequent meals and regular energy intake might enhance cardiometabolic health cross-sectionally, highlighting the need for prospective studies to further investigate these associations and the mediating role of BMI.

Worldwide type 2 diabetes (T2D) prevalence is increasing dramatically. The present study aimed to evaluate the association between dietary habits and T2D in an Iranian adult population using a cross-sectional analysis of the Shahedieh cohort study. Participants were adults aged 35–70 years (n 9261) from Zarch and Shahedieh, Yazd, Iran, who attended the baseline phase of the Shahedieh cohort study. Dietary habits including meal frequency, fried-food consumption, adding salt to prepared meals and grilled-food consumption were assessed by a standard questionnaire. T2D was defined as fasting plasma glucose (FPG) ≥126 mg/dl according to the American Diabetes Association. Multiple logistic regression assessed the association between dietary habits and T2D. Individuals who consumed a meal more than six times per day compared to three times per day had greater odds for T2D (OR 2⋅503, 95 % CI 1⋅651, 3⋅793). These associations remained significant in a fully adjusted model. There was a significant association between greater intakes of fried foods and prevalence of T2D (OR 1⋅294, 95 % CI 1⋅004, 1⋅668) in the adjusted model. No significant associations were observed between other dietary habits (adding salt to prepared meals and grilled-food consumption) and odds of T2D in all crude and adjusted models. In conclusion, we have highlighted the association between meal and fried-food consumption frequencies with risk of T2D. Large longitudinal studies in different ethnicities are needed to confirm these associations.

In growing pigs, reduced growth during heat stress (HS) is mainly related to decreased feed intake. The study aimed to determine whether the reported positive effects of live yeast (LY) supplementation in HS pigs were due to a modified feeding behaviour or energy metabolism, and if these can be replicated by imposing an increased meal frequency. The effect of LY supplementation (0 (NS) v. 100 (LY) g/ton of feed), and of feeding window (FW) (unlimited or Unli, 2FW of 1 h each and 8FW of 15 min each) were measured in entire male finishing pigs (n 36). Ambient temperature was at 22°C during the thermoneutral (TN) period (5 d) and at 28°C during the HS period (5 d). Heat exposure decreased DM intake (DMI) and retained energy (RE) (–627 and −460 kJ·kg BW–0·60 · d–1, respectively; P < 0·01). During HS, LY supplementation in Unli pigs decreased inter-meal intervals (P = 0·02) attenuating HS effect on DMI which tended to improve RE (P = 0·09). NS – 8FW had higher DMI and RE than NS – 2FW (P < 0·05) but protein deposition (PD) were similar. Supplemented pigs had higher PD during HS regardless of FW (+18 g · d–1; P = 0·03). Comparing the 2FW groups, improved heat tolerance of LY-supplemented pigs were due to improved insulin sensitivity (P < 0·05) and latent heat loss capacity after a meal (P < 0·05) allowing them to increase their DMI (via an increased number of meals) and thus their energy efficiency. Imposing an increased meal frequency improved DMI in HS pigs but did not replicate positive effects of LY on PD.

Dietary habits play an important role in the development of obesity and type 2 diabetes. However, evidence on association between diet frequency and type 2 diabetes was limited and inconclusive. We aimed to examine the association between meal frequency and risk of type 2 diabetes. The cohort study used data from China Health and Retirement Longitudinal Study of 8874 community-dwelling people aged over 45 years. Participants were classified as eating two meals per day, three meals per day and four meals per day. Multiple Poisson regression models were used to examine risk of 4-year incident type 2 diabetes among people who ate more or less than three meals per day compared with people who ate three meals per day. We documented 706 type 2 diabetes cases during follow-up. After adjustment for known risk factors for type 2 diabetes, except for BMI, participants who ate four meals per day were at a lower risk of type 2 diabetes than those who ate three meals per day (relative risk(RR) = 0·73 (0·58, 0·92)). After further adjustment for baseline BMI, the association was slightly attenuated but remained statistically significant (RR = 0·76 (0·60, 0·97)). Subgroup analysis showed that the fully adjusted RR of type 2 diabetes for people eating four meals per day were 0·66 (0·48, 0·91) and 0·93 (0·65, 1·34) among those had a BMI < 25 and ≥ 25 kg/m2, respectively. Eating four meals per day, compared with eating three meals per day was associated with lower risk of developing type 2 diabetes in a Chinese population, particularly in those with a BMI < 25 kg/m2.

Maternal dietary feeding practice is one of the proxy indicators of maternal nutrient adequacy and it improves outcomes for both mothers and their offspring. The minimum maternal dietary diversity score of lactating women is defined as when the mother ate at least four and above food groups from the nine food groups 24 h preceding the survey regardless of the portion size. Therefore, the present study aimed to determine the minimum dietary diversity score (MDDS) and its predictors among lactating mothers in the Pastoralist community, Ethiopia. A community-based cross-sectional study design was employed on 360 lactating mothers using a multi-stage sampling technique from 5 January 2020 to 10 February 2020. Data were collected using questionnaires and anthropometry measurements. Data were entered using EPI-data 4.6.02 and exported into SPSS version 25. Statistical significance was declared at P-value <0⋅05 at multivariable logistic regression. Only one in four lactating mothers met the MDDS. The majority of them consumed cereals in the preceding 24 h of data collection. The most important predictors were maternal meal frequency (adjusted odds ratio (AOR) 6⋅26; 95 % confidence interval (CI) (3⋅51, 11⋅15)), antenatal care (ANC) follow-up one to three times and four and above times (AOR: 2⋅58; 95 % CI (1⋅24, 5⋅36), 4⋅77 (1⋅90, 11⋅95), respectively) and secondary paternal education (AOR 2⋅97; 95 % CI (1⋅44, 6⋅11)). The MDDS among lactating mothers was low. Paternal education, maternal meal frequency and ANC follow-up were the significant predictors. Therefore, to improve maternal dietary diversity score emphasis should be given to those predictors.

Studying irregular meal patterns fits in with the latest research focusing not only on what people eat but also when they eat, also called chrono-nutrition. Chrono-nutrition involves studying the impact of nutrition on metabolism via circadian patterns, including three aspects of time: (ir)regularity, frequency and clock time. The present paper aimed to narratively review research on irregular meal patterns and cardiometabolic consequences. Only few cross-sectional studies and prospective cohort studies were identified, and most of these suggested that eating meals irregularly is associated with a higher risk of the metabolic syndrome and cardiometabolic risk factors, including BMI and blood pressure. This was supported by two randomised controlled intervention studies showing that consuming meals regularly for 2 weeks v. an irregular meal pattern, led to beneficial impact on cardiometabolic risk factors as lower peak insulin, lower fasting total and LDL-cholesterol, both in lean and obese women. In conclusion, the limited evidence on meal regularity and cardiometabolic consequences supports the hypothesis that consuming meals irregularly is adversely associated with cardiometabolic risk. However, it also highlights the need for more large-scale studies, including detailed dietary assessment to further advance the understanding of the impact of chrono-nutrition on public health.

The association between eating frequency (EF) and adiposity in young populations is inconsistent. This cross-sectional study examined associations of EF, meal frequency (MF) and snack frequency (SF) with adiposity measures in US children aged 6–11 years (n 4346) and adolescents aged 12–19 years (n 6338) participating in the National Health and Nutrition Examination Survey 2003–2012. Using data from two 24-h dietary recalls, all eating occasions providing ≥210 kJ of energy were divided into meals or snacks based on contribution to energy intake (≥15 or <15 %), self-report and time (06.00–09.00, 12.00–14.00 and 17.00–20.00 hours or others). When analysed without adjustment for the ratio of reported energy intake:estimated energy requirement (EI:EER), all measures of EF, MF and SF showed inverse or null associations with overweight (BMI≥85th percentile of BMI-for-age) and abdominal obesity (waist circumference≥90th percentile) in both children and adolescents. After adjustment for EI:EER, however, EF and SF, but not MF, showed positive associations in children, irrespective of the definition of meals and snacks. In adolescents, after adjustment for EI:EER, positive associations were observed for EF (abdominal obesity only), SF based on energy contribution and MF based on self-report, whereas there was an inverse association between MF based on energy contribution and overweight. In conclusion, higher SF and EF, but not MF, were associated with higher risks of overweight and abdominal obesity in children, whereas associations varied in adolescents, depending on the definition of meals and snacks. Prospective studies are needed to establish the associations observed here.

Evidence of associations between meal frequency (MF) and snack frequency (SF) and diet and obesity in young populations is limited. This cross-sectional study examined MF and SF in relation to dietary intake and adiposity measures in British children aged 4–10 years (n 818) and adolescents aged 11–18 years (n 818). Based on data from a 7-d weighed dietary record, all eating occasions were divided into meals or snacks on the basis of contribution to energy intake (≥15 or <15 %) or time (06.00–10.00, 12.00–15.00 and 18.00–21.00 hours or others). All measures of MF and SF showed positive associations with energy intake, except for MF based on energy contribution in children. Irrespective of the definition of snacks, SF was associated with higher intakes of soft drinks, confectionery and total sugar, lower intakes of cereals, fish, meat, protein, PUFA, starch and dietary fibre, and a lower diet quality (assessed by the Mediterranean diet score, except for SF based on energy contribution in adolescents). MF based on time, but not based on energy contribution, was associated with higher intakes of confectionery and total sugar, lower intakes of fish, protein, PUFA and starch, and, only in children, a lower diet quality. All measures of MF and SF showed no association with adiposity measures. In conclusion, this cross-sectional study in British children and adolescents suggests that decreasing the number of small eating occasions (<15 % of total energy intake) regardless of the time of day may be important to improve diet quality but not adiposity.

There have been reports of an inverse relationship between meal frequency (MF) and adiposity. It has been postulated that this may be explained by favourable effects of increased MF on appetite control and possibly on gut peptides as well. The main goal of the present study was to investigate whether using a high MF could lead to a greater weight loss than that obtained with a low MF under conditions of similar energy restriction. Subjects were randomised into two treatment arms (high MF = 3 meals+3 snacks/d or low MF = 3 meals/d) and subjected to the same dietary energy restriction of − 2931 kJ/d for 8 weeks. Sixteen obese adults (n 8 women and 8 men; age 34·6 (sd 9·5); BMI 37·1 (sd 4·5) kg/m2) completed the study. Overall, there was a 4·7 % decrease in body weight (P < 0·01); similarly, significant decreases were noted in fat mass ( − 3·1 (sd 2·9) kg; P < 0·01), lean body mass ( − 2·0 (sd 3·1) kg; P < 0·05) and BMI ( − 1·7 (sd 0·8) kg/m2; P < 0·01). However, there were NS differences between the low- and high-MF groups for adiposity indices, appetite measurements or gut peptides (peptide YY and ghrelin) either before or after the intervention. We conclude that increasing MF does not promote greater body weight loss under the conditions described in the present study.

The aim of this study was to investigate the effect of feeding frequency on total tract digestibility and plasma glucose, insulin, urea, gastrin and cortisol concentrations at rest and following exercise in seven Standardbred horses in race training. The horses were fed every 12 h (twice a day, 2TD) and every 4 h (six times a day, 6TD) for 25 days, in a cross-over design. The diet (64% grass hay, 36% concentrates on weight basis) was fed at twice the maintenance energy requirement. Blood samples were taken every hour for 24 h on day 17, total collection of urine and faeces was made on days 19–21 and an intensive exercise test was performed on day 25. Altering feeding frequency caused small variations in diurnal plasma glucose, urea, gastrin and cortisol concentrations and did not affect total tract nutrient digestibility. There was an increase in the mean diurnal plasma urea concentration on the 2TD regime and low levels of plasma insulin were observed 7 h after feeding 2TD. The response to intensive exercise on heart rate, plasma lactate and plasma glucose was similar on both treatments but the plasma insulin concentration was higher following exercise in the 2TD regime, indicating that post-exercise glucose metabolism was altered. In conclusion, this study shows that feeding athletic horses only 2TD caused metabolic signs resembling those observed during feed deprivation (low levels of plasma insulin and an increased diurnal plasma urea concentration) and an altered post-exercise glucose metabolism, but did not affect the digestive response.

The present paper presents a certain number of cultural elements which interact in the determination of the frequency of food intake. Approaches from various perspectives (historical, ethnological, anthropological, sociological) draw attention to two major aspects relating to the periodicity of food intake: the extreme cultural diversity and the continual modifications which have occurred over time and space. The various cultural models change and are subject to multiple influences, for example, cross-cultural, economic and historical. In addition, there are interactions between the models. The definitions of food intake and frequency play a major role in building up consumers' perceptions. These various perceptions are multiple (perception of self, of food and its virtues, the rules and moral values of consumption) and finally influence behaviours. Finally, and taking into account the systems of beliefs, the very nature of feeding behaviours may carry feelings of guilt for the subject. The study of real behaviours and their relationship with health is still incomplete for reasons of methodology and also of conceptual definition. In future, data collection has to take into account real behaviour as well as subjective perceptions and value judgements. A specific effort has to be made in the future to develop methodology. This should allow the collection of reliable data and particularly comparisons between studies, without oversimplifying and distorting cultural specificities.

Over the past two decades, substantial research has been conducted to investigate the idea that alterations in short-term nutritional intake play a role in influencing cognitive behaviour and mood. A portion of this research has examined specifically the effect of meal intake on the performance of mental tasks and subjective feelings of mood. Results of this research indicate that a number of variables including the timing and nutritional composition of the meal, nutritional status, habitual patterns of feeding behaviour, beliefs about food, and the nature of the mental tasks, can influence the effects of meals on cognitive behaviour. For example, studies have demonstrated that breakfast intake generally is associated with an improvement in cognitive performance later in the morning, while lunch intake is associated with an impairment in mid-afternoon performance on mental tasks and more negative reports of mood. Intake of nutrients late in the afternoon appears to have a positive effect on subsequent performance on tasks involving sustained attention or memory. Although research has provided insights into the role of meal intake on cognitive behaviour and mood, there are a number of factors which remain to be studied. These include the interaction of age, gender, activity level, meal composition, personality factors, stress with the effects of meals on cognitive behaviour. Additionally, more work is needed on the time-course of short-term nutrient effects, and the effects of chronic changes in meal intake on behaviour.

In the last 20 years, mainly due to optimum fluoride exposure, and practice of good oral hygiene procedures, an important reduction in caries has been observed, despite the fact that sugar consumption was maintained and/or was increasing during the same lapse of time. A sugar-caries relationship cannot be established in most of the industrialized countries and the dietary factor is not as preponderant in the caries process as it used to be two decades ago. The factors which seem to contribute the most significantly to the cariogenicity of the diet are the frequency of carbohydrate ingestion and eating patterns. The relative cariogenicity of food is not correlated with the amount of carbohydrate it contains. Even if sucrose remains the most important sugar consumed in sweets, beverages and confectionery products, all fermentable-carbohydrate foods can be involved in the caries process. The use of chewing gum and other xylitol-containing products have resulted in defined reduction in caries and represent interesting alternatives for high-caries-risk populations. Caries risk and oral health assessments as well as the evaluation of oral hygiene procedures and fluoride exposure should become essential tools in dietary counselling. People who receive optimum fluoride exposure and follow regular oral hygiene measures can safely use dietary carbohydrates, preferably during meals and two to three times daily in snacks or drinks.

Several epidemiological studies have observed an inverse relationship between people's habitual frequency of eating and body weight, leading to the suggestion that a ‘nibbling’ meal pattern may help in the avoidance of obesity. A review of all pertinent studies shows that, although many fail to find any significant relationship, the relationship is consistently inverse in those that do observe a relationship. However, this finding is highly vulnerable to the probable confounding effects of post hoc changes in dietary patterns as a consequence of weight gain and to dietary under-reporting which undoubtedly invalidates some of the studies. We conclude that the epidemiological evidence is at best very weak, and almost certainly represents an artefact. A detailed review of the possible mechanistic explanations for a metabolic advantage of nibbling meal patterns failed to reveal significant benefits in respect of energy expenditure. Although some short-term studies suggest that the thermic effect of feeding is higher when an isoenergetic test load is divided into multiple small meals, other studies refute this, and most are neutral. More importantly, studies using whole-body calorimetry and doubly-labelled water to assess total 24h energy expenditure find no difference between nibbling and gorging. Finally, with the exception of a single study, there is no evidence that weight loss on hypoenergetic regimens is altered by meal frequency. We conclude that any effects of meal pattern on the regulation of body weight are likely to be mediated through effects on the food intake side of the energy balance equation.

Two areas of sports nutrition in which the periodicity of eating has been studied relate to: (1) the habitually high energy intakes of many athletes, and (2) the optimization of carbohydrate(CHO) availability to enhance performance. The present paper examines how the timing and frequency of food and fluid intake can assist the athlete and physically-active person to improve their exercise performance in these areas. Frequent eating occasions provide a practical strategy allowing athletes to increase energy intake while concomitantly reducing the gastric discomfort of infrequent large meals. The optimization of CHO stores is a special challenge for athletes undertaking prolonged training or competition sessions. This is a cyclical process with post-exercise CHO ingestion promoting muscle and liver glycogen re-synthesis; pre-exercise feedings being practised to optimize substrate availability and feedings during exercise providing a readily-available source of exogenous fuel as endogenous stores become depleted. The timing and frequency of CHO intake at these various stages are crucial determinants for optimizing fuel availability to enhance exercise capacity.