The purpose of this study was to analyze the relationship between food intake and sleep patterns in healthy individuals. Fifty-two healthy volunteers (27 women and 25 men) were recruited to participate in the study. Volunteers underwent sleep evaluation through nocturnal polysomnography and completed a 3-day food diary to evaluate food intake. No differences in sleep patterns were observed in either gender, except in the percentage of stage 1 sleep, which was greater in men. Different correlations were observed between sleep and dietary variables according to gender. The correlation between dietary and sleep variables in men indicated a negative relationship between nocturnal fat intake and the sleep latency, including REM sleep. The percentage of nocturnal fat intake correlated with sleep efficiency, sleep latency, REM latency, stage 2 sleep, REM sleep, and wake after sleep onset (WASO) in women. The percentage of nocturnal caloric intake correlated with sleep latency and efficiency in women. We conclude that food intake during the nocturnal period is correlated with negative effects on the sleep quality of healthy individuals. Indeed, food intake near the sleeping period (dinner and late night snack) was negatively associated with sleep quality variables. More studies are necessary to elucidate the real effect of food intake on sleep.

Context: Recent studies show that dietary habits and obesity seem to be influenced by chronotype, which reflects an individual’s preference for the timing of sleeping, eating, and activity in a 24-hour period. Objective: This review aimed to analyze the association of chronotype with dietary habits, namely energy and macronutrient intakes, meal timing, and eating patterns, as well as with obesity. Data Sources: PubMed/MEDLINE, LILACS, and Google Scholar databases were searched between 2004 and 2020. Study selection was performed by 2 authors independently; disagreements on eligibility of articles were resolved by a third author. After assessment of 12 060 abstracts, 43 studies (21 articles on obesity; 13 on food consumption, meal timing, and eating patterns; and 9 that addressed both obesity and dietary behavior) were included. Data Extraction: A standard form was used to extract study design, country, number of participants, method of chronotype determination, and main findings. Data Analysis: Approximately 95% of included studies showed an association between eveningness and at least 1 unhealthy eating habit. Morningness was associated with regular consumption of fresh and minimally processed foods. In addition, about 47% of studies showed a higher association between late types and obesity. Conclusion: Late types are more likely to present unhealthy eating habits, such as eating late at night, skipping breakfast often, and eating processed/ultraprocessed foods, while early types are more likely to have healthy and protective habits, such as eating early and eating predominantly fresh/minimally processed foods. Intermediate types tend to have a pattern of health and eating more similar to early types than to late types. Late types are also more likely to present higher weight and body mass index than early or intermediate types. Systematic Review Registration: PROSPERO registration no. CRD42021256078.

Undergraduate students experience a form of circadian misalignment – known as “social jetlag” – that represents the discrepancy in timing between their circadian and social clocks. Whilst social jetlag is not dependent upon chronotype, the two phenomena tend to be related; evening types show a tendency to have a greater social jetlag, for example. Moreover, evening types have been found to be more likely to have inadequate eating habits than do morning types. The objective of this study was to examine the relationship between chronotype, social jetlag, perceived sleep debt and dietary intake in Brazilian undergraduate students. The chronotype was derived from mid-sleep time on free days (MSF) at the weekend. Social jetlag was calculated as the absolute difference between mid-sleep time on weekdays and weekends. Perceived sleep debt was calculated using the difference between students’ preferred weekday sleep duration and their self-reported actual weekday sleep duration. Correlations were found between chronotype and breakfast time (r = 0.24, p = 0.003) and lunch time (r = 0.19, p = 0.01). Multiple regression analyses showed that chronotype was positively associated with consumption of meat (β = 0.21; p = 0.003); social jetlag was negatively associated with consumption of beans (β = –0.16; p = 0.02) and perceived sleep debt was positively associated with consumption of beverages (β = 0.15; p = 0.02) and dairy products (β = 0.17; p = 0.01) and negatively associated with consumption of cereals and pasta (β = –0.16; p = 0.02). It is concluded that, in undergraduate students, chronotype (MSF), social jetlag and perceived sleep debt can influence the type and amount of some food groups consumed at mealtimes.

An individual’s chronotype is a trait which reflects his/her diurnal preferences for the times of rest and activities, and displays a continuum from morningness to eveningness. Studies have shown that eveningness tends to be associated with a less healthy lifestyle, including increased likelihood of developing obesity. In this study, we examined the relationship between chronotype and food intake, physical sleep and activity in 72 resident physicians (52 women and 20 men). Assessments included chronotype evaluation by the Horne and Ostberg Morningness-Eveningness questionnaire (MEQ); food intake pattern through a self-administered food diary that was kept over the course of 3 non-successive days; physical activity level, using the Baecke questionnaire (BQ); sleep quality and quantity using the Pittsburgh Sleep Quality Index (PSQI); and sleepiness, Epworth Sleepiness Scale (ESS). Linear regression analyses, after adjustments for age, sex, body mass index (BMI), hours of additional work per week ESS and total physical activity score, showed that the chronotype score was negatively associated with cholesterol (coefficient = −0.24; p = 0.04), sweets (coefficient = −0.27, p = 0.03) and vegetables (coefficient = −0.26; p = 0.04) intakes. Following the same statistical adjustments, the chronotype score was positivity associated with leisure-time index (coefficient = 0.26, p = 0.03) and BQ total score (coefficient = 0.27, p = 0.03). We concluded that most issues related to nutrition problems and unhealthy lifestyle were associated with scores indicative of eveningness. These findings emphasize the importance of assessing an individual’s chronotype when examining feeding behavior.

Chronic disruption of the synchronous relationship between endogenous and exogenous circadian timing is associated with the development of obesity and metabolic disease. Social jetlag is a measure of circadian misalignment and has been identified as a risk factor for overweight and related diseases. However, the mechanisms involved in this relationship remain underexplored. The objective of this study was to investigate the association between social jetlag and food consumption at late meal timing in patients with obesity-related chronic diseases. This study included 792 individuals (73% female; age 55.9 ± 12.4 years) in which the prevalence of social jetlag (>1h) was 24.4% (n = 194). Participants with social jetlag reported late meal timing for breakfast, early afternoon snack and dinner. Individuals with social jetlag also reported a higher intake of total calories (kcal), protein, total fat, saturated fat, cholesterol, and servings of meat and eggs and sweets in relation to those without social jetlag. Regarding the consumption during each meal of the day, participants with social jetlag had consumed more calories, saturated fat and cholesterol during dinner; more protein, total fat, saturated fat, and cholesterol during lunch; and more total fat and saturated fat during morning snack. In addition, individuals with social jetlag had a higher risk of inadequate consumption of total fat, saturated fat and cholesterol intake when compared with those without social jetlag. We conclude that social jetlag is associated with a poor diet and later meal times, which should be avoided in individuals with obesity-related chronic diseases. More studies are needed to confirm these findings.

Social jetlag – a measure of disruption of the circadian system – has been linked to obesity, but its association with metabolic complications in non-communicable chronic diseases (NCCDs) is unknown in the literature. We examined the associations between social jetlag and obesity status and metabolic parameters among individuals with NCCDs. Patients (n = 792) with NCCDs (obesity, systemic arterial hypertension, type 2 diabetes mellitus or dyslipidaemia) attended clinics of the public health service of the city of Uberlândia, Minas Gerais State, Brazil. They were classified in three obesity statuses: non-obese: BMI < 30 kg/m²; metabolically healthy obese (MHO): BMI ≥ 30 kg/m²and less than three high-risk biomarkers for metabolic syndrome; and metabolically unhealthy obese (MUO): BMI ≥ 30 kg/m²and with high-risk values on three or more biomarkers for metabolic syndrome. After adjustments for confounding variables, social jetlag was positively associated with fasting glucose levels among all subjects (β = 0.08, p = 0.03) and MUO subjects (β = 0.32, p < 0.001). Patients with social jetlag (>1 h) presented a significant odds ratio (OR) of being overweight (OR = 2.0, confidence interval (CI) = 1.2–3.6, p = 0.006) and MUO (OR = 1.8, CI = 1.1–2.8, p = 0.01). These results suggest that social jetlag is associated with a higher risk of overweight and related metabolic complications in individuals with NCCDs.