The Influence of Nocturnal Food Intake in Eating Behavior of Night Workers: Randomized Cross-over Study.

Night work causes restriction of sleep time and circadian misalignment and, therefore, have been associated with nutritional and metabolic impairments. The objective of the present study is to verify the influence of night work and food intake in this period on the behavior of the following day. The workers selected by criteria and inclusion and exclusion will be evaluated at the baseline: anthropometric parameters, food consumption and perception, duration of food consumption, sleep habits and chronobiological pattern (sleep monitoring by actigraphy, chronotype, social jet lag), parameters biochemical (blood count, lipidogram, C-reactive protein, cortisol, glucose, insulin).Subsequently, 30 workers will integrate a randomized and controlled crossover clinical study with three randomly established interventions: (1) two nights of work without meals during the shift; (2) two nights of work with a meal during the shift; (3) two nights sleep. Participants will go to the laboratory the morning after the second night of each condition to offer a test meal ad libitum, which will consist of foods of various compositions and food groups. Preprandial metabolic assessments will be conducted (ghrelin, GLP-1 - glucagon-like peptide 1, PYY-peptide YY). The following postprandial evaluations will be carried out and in the 24 hours following the experiment: food choices (record of all foods) and food perceptions (hunger, appetite, satiety and eating). It is expected to determine how nocturnal versus nocturnal work, and nocturnal fasting versus nocturnal fasting affect the next day's food choices.