Food Intake in Night Workers: A Conflict Between Photic and Non-Photic Synchronizers

Corresponding author e-mail: crmoreno@usp.br Working at night or in shifts causes changes in feeding behavior, since this process can be concurrently influenced by diverse factors of biological, social and cultural determinants. Since the end of the 1960s there have been studies about eating habits among shift workers. The changes in food consumption in these workers might be explained by the fact that night work is a condition that leads to an imbalance between the meal schedule and intestinal mobility, caused by changes in the quality of food ingested and a reduction in time for breaks at work. Shift workers complain of a lack of appetite, which can be associated with changes in the periodicity of meals. The meal schedule even has an influence on the secretion of digestive juices, and on the absorption and digestion of food. In fact, there appears to be a consensus among researchers in the field that the distribution of total caloric intake over the 24 hours does not vary between different shifts, however, there are differences related to dietary content and caloric distribution over the course of the day among shift workers. Research related to nutrition among shift workers ranges from epidemiological studies which provide evidence for shift work being a risk factor for various diseases such as gastrointestinal and cardiovascular illnesses, for instance, to studies centered on the distribution of food ingestion over 24 hours, particularly on the timing of food ingestion among the workers. Some of these studies include the social repercussions of the meal schedules as well. Publication History Article published online: 16 June 2026 © 2009. Brazilian Sleep Academy. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Thieme Revinter Publicações Ltda. Rua Rego Freitas, 175, loja 1, República, São Paulo, SP, CEP 01220-010, Brazil