Abordagem crononutricional de trabalhadores em turnos

Abstract

Introduction: Shift workers suffer from imbalances in the circadian timing system (CTS) and changes in lifestyle habits, which seem to increase the risk of developing metabolic and nutritional disorders. Important changes in food consumption have been addressed in the literature, with special changes in mealtimes, but studies are still insufficient to determine the impact of these habits on the diet composition and the etiology of nutritional diseases. Objectives: To evaluate the association between the time-related eating patterns and the total daily calories and macronutrients consumed by fixed day and night workers. It was also aimed to evaluate the effect of two different meal compositions consumed at nighttime by night workers on food consumption and perceptions of the subsequent meal. Material and Methods: The first article presented in this thesis had a transversal design and was performed with 81 military police officers (29-day workers and 52-night workers). Calories and macronutrients consumption was assessed using a three-day food diary. The time-related eating patterns included the number of meals, the time of the first and last meal, the eating duration, and caloric midpoint. Participants were classified as “early” or “late eaters” according to the median of caloric midpoint. Multiple linear regression analysis separated by work shift and adjusted for age and body mass index was used to analyze the association between the time-related eating pattern variables and total daily caloric and macronutrients intake. The second article was a randomized crossover study performed with 14-night workers who worked in the healthcare area of a public hospital in the city of Uberlândia. Participants were monitored regarding food consumption and sleep habits in the seven days before the experimental protocol. Subsequently, the individuals were randomized and consumed two isocaloric meals at two moments separated by a six-day washout – a high-protein/moderate-carbohydrate (HP/MCHO) meal containing 45% of carbohydrate, 35% of protein, and 20% of fat vs. low-protein/high-carbohydrate (LP/HCHO) meal containing 65% of carbohydrate, 15% of protein, and 20% of fat, both consumed during the night shift work. On the following day, post-interventions, participants were instructed to complete a food record including the report of perceptions in each meal. Generalized estimated equations were used to examine the effect of both conditions on food consumption and perceptions the following day. Results: Night workers had a later last meal (p<0.001), greater eating duration (p<0.001), and later caloric midpoint (p=0.037) compared to day workers. In addition, late eaters regardless of the work shift consumed more energy (p=0.028), fat (p=0.006) and protein (calories: p<0.001; percentage: p=0.042), and fewer carbohydrates (p=0.031) when compared to early eaters. The time of the last meal was positively associated with energy consumption (day workers: β=0.352; p=0.044; night workers: β=0.424; p=0.002) and protein (day workers: β=0.451; p=0.013; night workers: β=0.536; p<0.001) in both shifts, and only with carbohydrate consumption in night workers (β=0.346; p=0.016), and fat β=0.286; p=0.042). The eating duration was positively associated with energy (day workers: β=0.473; p=0.004; night workers: β=0.320; p=0.023) and carbohydrate (day workers: β=0.418; p=0.011; night workers: β=0.364; p=0.010) in both shifts. Results of the randomized crossover study showed a greater appetite for snack foods after the HP/MCHO condition compared to LP/HCHO condition. On the following day, after the HP/MCHO condition compared to LP/HCHO, the percentage of carbohydrate consumed was higher during lunch (48.14% vs. 36.98%), while after the percentage of lipid consumption was lower during dinner (27.34% vs. 40.39%). Conclusion: It is concluded that night worker presented a greater eating window compared to day workers. In general, the results of the first article suggest that the time-related eating patterns variables indicative of nighttime/dawn food consumption seem to lead to increased total daily calories and macronutrients. In addition, the findings of the randomized crossover study suggest that the composition of the meal consumed at night may affect carbohydrates, proteins and fat consumption, and dietary perceptions the following day.