This study aimed to identify meal and snack patterns and assess their association with sleep timing in schoolchildren. This is a cross-sectional study carried out in 2018/2019 with 1333 schoolchildren aged 7–14 years from public and private schools in Florianópolis, Brazil. Previous-day dietary intake data for breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner and evening snack were collected using a validated online questionnaire. Sleep timing was measured by the midpoint of sleep and classified as quartiles (very early, early, late and very late). Latent class analysis was performed to identify meal and snack patterns, and multinomial logistic regression was used to assess associations. Students with very late sleep timing were less likely to consume the ‘coffee with milk, bread and cheese’ breakfast pattern compared with very early group. Also, the former were more likely to consume the ‘mixed’ breakfast pattern (healthy and unhealthy foods) compared with very early students. The latter were more likely to eat the ‘Brazilian traditional, processed meat, egg and fish’ lunch pattern to the late students and less likely to consume the ‘pasta and cheese’ lunch pattern compared with the students with later sleep timing. Students with later sleep timing were more likely to eat ultra-processed food at mid-afternoon snacks compared with early group. The study findings suggest that morning preference appears to promote healthier breakfast, lunch and afternoon snack patterns, whereas later sleep timing may pose challenges in maintaining healthy patterns at these meals/snacks.

Recent studies have focused on habitual intake without addressing meal-specific intakes. We aimed to identify meal-specific dietary patterns and their contribution to habitual dietary patterns. This cross-sectional study was conducted on 838 adults, both sexes who attended the health centres in Tehran. Dietary data were recorded by three 24-h dietary recalls (24hDR). Dietary patterns were identified by using principal component analysis on meal-specific and overall food intakes. Intraclass correlation (ICC) was used as a measurement of consistency across meals and days. Correlation analysis and linear regression (partial R 2) were used for meals contribution. Four habitual dietary patterns were derived from average dietary intake of 3-d 24hDR labelled as ‘Western’, ‘Healthy’, ‘Traditional’ and ‘Legume and broth’. Also, we identified two major dietary patterns on each meal level (factor 1 and 2 for breakfast, lunch, afternoon snack and dinner). The highest contribution of energy intake was observed in lunch (25·7 %), followed by dinner (20·81 %). Consistency of food groups was the highest across days (ICC tea = 0·58) and breakfasts (ICC tea = 0·60). Dinner had a strong correlation coefficient with the ‘Western’ habitual dietary pattern then followed by lunch. Similarly, dinner and lunch contributed the most (r and partial R 2) to the ‘Western’ habitual dietary pattern. Our results suggest that habitual dietary patterns to several extents are formed at meal levels, and dinner has a greater contribution to the habitual dietary patterns in Iranian people. This may help planning for local dietary guidelines according to the time of eating to promote public health.

Associations between eating behaviours and dietary variables have not been thoroughly investigated in healthy postmenopausal women in a real-life uncontrolled context. To investigate how eating behaviours (cognitive dietary restraint, disinhibition and susceptibility to hunger) were associated with food and drink consumption, energy density and meal pattern in 112 healthy postmenopausal women (age 56·8 (sd 4·4) years) not on hormonal therapy. Women completed a 3 d weighed food record and filled out the Three-Factor Eating Questionnaire. The sample was divided according to the median of the distribution of cognitive dietary restraint and disinhibition (9 and 6 respectively). Both subgroups of women with high restraint level (presenting either high or low disinhibition) consumed a diet with a lower energy density than subgroups of women with lower restraint level. Women with high restraint–low disinhibition had a lower consumption of red meat and processed meat and a lower consumption of diet soft drinks than women with low restraint–high disinhibition. They were also characterised by a higher intake of whole grains than women with high restraint–high disinhibition and than women with lower restraint level (with either high or low disinhibition). Women with high restraint–high disinhibition levels showed differences in dietary variables when compared with subgroups of women with lower restraint level, namely for refined grains and diet soft drinks. We conclude that in healthy postmenopausal women, dietary consumption of specific food and drink may be related to particular eating behaviours. Women with high restraint and low disinhibition levels generally showed the most healthy dietary pattern.

A gorging pattern of food intake has been shown to enhance lipogenesis and increase body weight, which may be due to large fluctuations in storage and mobilisation of nutrients. In a state of energy balance, increasing meal frequency, and thereby decreasing inter-meal interval, may prevent large metabolic fluctuations. Our aim was to study the effect of the inter-meal interval by dividing energy intake over two or three meals on energy expenditure, substrate oxidation and 24 h satiety, in healthy, normal-weight women in a state of energy balance. The study was a randomised crossover design with two experimental conditions. During the two experimental conditions subjects (fourteen normal-weight women, aged 24·4 (sd 7·1) years, underwent 36 h sessions in energy balance in a respiration chamber for measurements of energy expenditure and substrate oxidation. The subjects were given two (breakfast, dinner) or three (breakfast, lunch, dinner) meals per d. We chose to omit lunch in the two meals condition, because this resulted in a marked difference in inter-meal-interval after breakfast (8·5 h v. 4 h). Eating three meals compared with two meals had no effects on 24 h energy expenditure, diet-induced thermogenesis, activity-induced energy expenditure and sleeping metabolic rate. Eating three meals compared with two meals increased 24 h fat oxidation, but decreased the amount of fat oxidised from the breakfast. The same amount of energy divided over three meals compared with over two meals increased satiety feelings over 24 h. In healthy, normal-weight women, decreasing the inter-meal interval sustains satiety, particularly during the day, and sustains fat oxidation, particularly during the night.

In order to better understand the factors that may influence and regulate the intake of the macronutrients carbohydrate, fat and protein a 7 d diet diary technique was employed to study eating behaviour in the natural environment of free-living human subjects. In general, factors that promote energy intake tend to promote fat and protein intake to a greater extent than carbohydrate intake. This increased intake occurs as the result of: environmental factors such as social facilitation and the time of day, week or lunar phase; subjective factors such as hunger and elation; individual difference factors such as obesity, restraint and ageing. There are indications that the intake of macronutrients is regulated by negative feedback systems. In the short term, the amount of protein remaining in the stomach at the onset of a meal appears to have a restraining effect on intake, especially protein intake. Over several days, macronutrient intake appears to be affected by a nutrient-specific delayed negative feedback. Protein intake during 1 d is negatively associated with protein intake 2 and 3 d later, while carbohydrate intake is negatively related to later carbohydrate intake, and fat intake to later fat intake; both peaking after a 2 d delay. Studies of the intakes of twins suggested that many aspects of the control of macronutrient intake are influenced by inheritance; these factors include the overall amounts ingested, the before-meal stomach contents and the responsiveness of the subject to the negative impact of the stomach contents. The results indicate that macronutrient intakes are regulated by multiple persistent processes that are to a large extent inherited.