Study Objectives: The purpose of this study was to analyze the relationship between food intake and sleep patterns in healthy individuals. Methods: 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. Results S C I E N T I F I C I N V E S T I G A T I O N SO besity is becoming a worldwide epidemic. 1 The etiology of this disease is multifactorial; among the causes are changes in food intake, 2 life style, environment, 2,3 and genetics, 4,5 in addition to physiological 6 and psychological 7 infl uences and, more recently, alterations in sleep patterns. [8][9][10][11] Sleep curtailment has become common due to the demands and opportunities of modern society.12 Recent studies show that alterations in sleep time can infl uence various aspects associated with the nutritional and metabolic balance of the body, such as the control of body mass, 9,11 food intake, 10,13 glycemic levels, 14,15 and the levels of cholesterol and triacylglycerol. 16 Although some studies show that short duration sleep changes the food intake pattern and may cause obesity, 9-11 few studies have analyzed whether the opposite casual sequence also occurs; that is, if food intake promotes alterations in the sleep pattern. Indeed, studies that have examined this matter are controversial and use different methodologies. Some studies indicate an impairment of sleep quality when there is an excessive carbohydrate intake. 17,18 Driver et al.,19 however, comparing the effect of an evening meal on nocturnal sleep in seven healthy men, did not fi nd any effect. Therefore, this study proposes to analyze the correlation between habitual food intake and sleep patterns in healthy individuals. METHODS SampleFifty-two healthy volunteers (27 women and 25 men) between 19 and 45 years old took part in this study. The participants were young adults and were non-obese. They were sedentary and not taking medication. They were all nonsmokers and spent regular times in bed at night (7.5-8.5 h). The subjects did not suffer from sleep disturbances (apnea and hypopnea index [AHI] < 5, and periodic leg movements [PLM] during sleep were < 5, as assessed bRIEF SUMMARY Current Knowledge/Study Rationale: Few studies have analyzed if food intake promotes alterations in the sleep pattern. Therefore, the objective of this study was to analyze the correlation between habitual food intake and sleep patterns in healthy individuals. Study Impact: This study demonstrated that a higher food intake close to the sleeping period is associated with negative aspects of sleep patterns in healthy individuals, especially in women. However, this is an area poorly explored in the literature, and more studies are necessary to elucidate the real infl uence of food intake upon sleep.

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.

Shift work has been associated with a higher propensity for developing nutritional problems and obesity. However, the possible changes in leptin and ghrelin (2 hormones that contribute importantly to the central regulation of food intake) concentrations in this population are poorly described. The objective of the study was to evaluate the daily concentrations of leptin, nonacylated ghrelin, and acylated ghrelin and the appetite ratings in men working different shift schedules. Daily concentrations of nonacylated ghrelin, acylated ghrelin, and leptin and appetite were measured in 3 groups of subjects: workers on fixed night shifts (n = 9), fixed early morning shifts (n = 6), and fixed day shifts (n = 7). Appetite was evaluated by a validated questionnaire. Blood samples were collected every 4 hours over the course of 24 hours for a total of 6 samples. When comparing the 3 groups, leptin concentrations at 8:00 am and 4:00 pm for those workers on the day shift were significantly lower than for those on the early morning shift; and concentrations at noon for those workers on the day shift were significantly lower than for those on the night shift. Nonacylated and acylated ghrelin concentrations were significantly lower for those workers on the early morning shift than for those on the day shift. In general, appetite was the lowest in those working the early morning shift. Shift workers on the early morning shift have lower appetites and concentrations of leptin and nonacylated and acylated ghrelin than the workers on other shifts. Further studies are required to better understand the detailed needs of these individuals.

The present review investigates the role of sleep and its alteration in triggering metabolic disorders. The reduction of the amount of time sleeping has become an endemic condition in modern society and the current literature has found important associations between sleep loss and alterations in nutritional and metabolic aspects. Studies suggest that individuals who sleep less have a higher probability of becoming obese. It can be related to the increase of ghrelin and decrease of leptin levels, generating an increase of appetite and hunger. Sleep loss has been closely associated with problems in glucose metabolism and a higher risk for the development of insulin resistance and diabetes, and this disturbance may reflect decreased efficacy of the negativefeedback regulation of the hypothalamic-pituitary-adrenal axis. The period of sleep is also associated with an increase of blood lipid concentrations, which can be intensified under conditions of reduced sleep time, leading to disorders in fat metabolism. Based on a review of the literature, we conclude that sleep loss represents an important risk factor for weight gain, insulin resistance, type 2 diabetes and dyslipidaemia. Therefore, an adequate sleep pattern is fundamental for the nutritional balance of the body and should be encouraged by professionals in the area.

Animal studies strongly suggest that timed feeding can have beneficial physiological effects, including protection against the obesogenic and metabolic consequences of a high-fat diet. However, the relationship between variables related to the timing of eating and diet quality in pregnancy women, which is considered as a period of nutritional vulnerability, is still poorly described in the literature. Therefore, the aim of the present study was to investigate the associations between time-related eating patterns and chronotype with diet quality of pregnant women. This cross-sectional study was conducted with 100 pregnant women in the first gestational trimester (≤12 weeks of gestation). The information regarding food intake was obtained by three 24-Hour Dietary Recall (24HR). Time-related eating patterns, i.e., the interval between the first and the last meal (eating duration), nightly fasting, time of the first and last meals, and number of meals eating on a day were determined. Chronotype was derived using the mid-sleep time on free days on weekends, with a further correction for calculated sleep debt. Diet quality was evaluated using the Brazilian Healthy Eating Index-Revised (BHEI-R), validated for the Brazilian population. Linear regression modeling analyses adjusted for confounders were used to investigate the association between time-related eating patterns and chronotype with diet quality. The BHEI-R total score was negatively associated with time of the first meal (β =  -0.355; p = 0.002; r adjusted = 0.141), and positively associated with eating duration (β = 0.262; p = 0.024; r adjusted = 0.086) and number of meals (β = 0.273; p = 0.019; r adjusted = 0.091). In addition, the score of total fruit component was negatively associated with chronotype (β = -0.236; p = 0.033; r adjusted = 0.078), time of the first meal (β = -0.393; p = 0.001; r adjusted = 0.171), and positively associated with eating duration (β = 0.259; p = 0.022; r adjusted = 0.087) and number of meals (β = 0.376; p = 0.001; r adjusted = 0.159). The score for whole fruit component was negatively associated with time of the first meal (β = -0.388; p = 0.001; r adjusted = 0.152), and positively associated with number of meals (β = 0.403; p = 0.001; r adjusted = 0.164). A longer eating duration, earlier time of the first meal, higher number of meals and morningness tendency are associated with a better diet quality in the first gestational trimester - higher scores of the total BHEI-R and/or fruit components. We suggest that nutritional guidelines should consider time-related eating patterns and chronotype to ensure good diet quality of pregnant women since the beginning of gestation, contributing on prevention of metabolic-nutritional complications.

Shiftwork is common in medical training and is necessary for 24-h hospital coverage. Shiftwork poses difficulties not only because of the loss of actual sleep hours but also because it can affect other factors related to lifestyle, such as food intake, physical activity level, and, therefore, metabolic patterns. However, few studies have investigated the nutritional and metabolic profiles of medical personnel receiving training who are participating in shiftwork. The aim of the present study was to identify the possible negative effects of food intake, anthropometric variables, and metabolic and sleep patterns of resident physicians and establish the differences between genders. The study included 72 resident physicians (52 women and 20 men) who underwent the following assessments: nutritional assessment (3-day dietary recall evaluated by the Adapted Healthy Eating Index), anthropometric variables (height, weight, body mass index, and waist circumference), fasting metabolism (lipids, cortisol, high-sensitivity C-reactive protein [hs-CRP], glucose, and insulin), physical activity level (Baecke questionnaire), sleep quality (Pittsburgh Sleep Quality Index; PSQI), and sleepiness (Epworth Sleepiness Scale; ESS). We observed a high frequency of residents who were overweight or obese (65% for men and 21% for women; p = 0.004). Men displayed significantly greater body mass index (BMI) values (p = 0.002) and self-reported weight gain after the beginning of residency (p = 0.008) than women. Poor diet was observed for both genders, including the low intake of vegetables and fruits and the high intake of sweets, saturated fat, cholesterol, and caffeine. The PSQI global scores indicated significant differences between genders (5.9 vs. 7.5 for women and men, respectively; p = 0.01). Women had significantly higher mean high-density lipoprotein cholesterol (HDL-C; p < 0.005), hs-CRP (p = 0.04), and cortisol (p = 0.009) values than men. The elevated prevalence of hypertriglyceridemia and abnormal values of low-density lipoprotein cholesterol (LDL-C; >100 mg/dL) were observed in most individuals. Higher than recommended hs-CRP levels were observed in 66% of the examined resident physicians. Based on current recommendations, a high prevalence of low sleep quality and excessive daytime sleepiness was identified. These observations indicate the need to monitor health status and develop actions to reassess the workload of medical residency and the need for permission to perform extra night shifts for medical residents to avoid worsening health problems in these individuals.

Shiftwork has been associated with a higher propensity for the development of metabolic disorders and obesity. The aim of the study was to investigate concentrations of glucose, cortisol, and insulin among fixed night workers (n = 9), fixed early morning workers (n = 6), and day workers (n = 7). Food intake was recorded for 7 days using a diary. Blood samples were collected every 4 h over the course of 24 h, yielding six samples. Total carbohydrate intake was lowest (p < .0005), whereas fat (p = .03) and protein (p < .0005) were highest on the early morning shifts. Early morning workers also had overall elevated cortisol levels relative to the other two groups. Cortisol levels appeared to be more influenced by time since waking prior to the shift than by time-of-day. Cortisol was highest for the early morning group than the day group 12 h after waking, and both the early morning and night groups had higher levels than the day group 16 h after waking (p < .05 in all cases). In contrast, the homesostatsis model assessment of insulin resistance (HOMA-IR) appeared to be more influenced by time-of-day than by time since waking prior to the shift. The early morning group had higher levels of HOMA-IR at 08:00 h than the other groups (p < .05). In conclusion, the early morning group had the highest overall concentrations of cortisol and tended to have higher levels of HOMA-IR, indicating that more attention should be given to these workers. Moreover, all three groups showed pronounced cortisol levels on awakening, suggesting that they may have adjusted to their awaking time. (Author: heloguarita@rgnutri.com.br ).

RESUMOA diminuição do tempo de sono tem se tornado uma condição endêmica na sociedade moderna, e a literatura atual tem encontrado importantes associações epidemiológicas entre o prejuízo no padrão habitual do sono e a obesidade. Com base nisso, a presente revisão analisou o papel do sono e da sua alteração no desencadeamento da obesidade. Diversos estudos indicam que os indivíduos que dormem menos têm uma maior possibilidade de se tornarem obesos, e que o encurtamento do sono aumenta a razão grelina/leptina, gerando o aumento do apetite e da fome. Isto pode estar associado à maior ingestão calórica e ao desencadeamento da obesidade. Dessa forma, um padrão adequado de sono torna-se fundamental para o controle da massa corporal, devendo ser incentivado pelos profissionais da saúde.