The Nutritional Status and Eating Habits of Shift Workers: A Chronobiological Approach

Abstract

The eating habits of workers may vary according to the season of the year and corresponding work schedule. A study aiming at verifying the changes in their diet in summer and winter, as well as the nutritional status of those who work fixed shifts, was conducted. The distribution during the 24h in the quantity of calories and macronutrients ingested and the circadian rhythm of calories consumed were also analyzed. The study was conducted on 28 workers subject to three fixed work (morning, afternoon, and night) shifts at a transport company in the city of São Paulo, Brazil. The mean age of the workers was 32.8 (SD+/-5.3) yrs. Their food intake was ascertained by the use of a 3-day dietary record, and their nutritional status was evaluated by their body mass index (BMI), both in winter and summer. Two-way ANOVA (shift and season) showed food consumption--measured in calories/24 h--was significantly higher in winter than summer (F(1.25)=11.7; p<0.001). No statistically significant differences were found among shifts (F(2.25)=0.85; p<0.44), and the interaction effect between shift and season was also not significant (F(2.25) = 0.15; p < 0.86). No seasonal difference in BMI was detected (Kruskal-Wallis test). Cosinor analyses showed circadian rhythmicity in calories consumed by morning (p < 0.01) as well as afternoon shift workers (p < 0.001), both in the winter and summer. Circadian rhythmicity in calories consumed by night workers was found only in summer (p < 0.01). The changes observed in the workers' eating habits from one season to another and during the 24h period show the need for further studies to help develop educational programs to improve the nutrition of shift employees taking into consideration shift schedule and season of the year when work is performed.

Meal irregularity and cardiometabolic consequences: results from observational and intervention studies

“…Subjects also noted the changes in their perception of eating habits when working night shifts and reported increasing dissatisfaction with their eating habits (23) . The findings of Lowden et al are supported by results from other cohort studies of shift workers (24)(25)(26) . A study in ninety-six male Swedish industrial workers found that energy intake and quality of food were not affected by shift work, but that the circadian distribution of food changed and coffee consumption increased (24) .…”

“…However, their total average daily energy intake was very high (12-71 MJ/d (3000-6000 kcal/d)). Another study of twenty-eight Brazilian shift workers found circadian rhythmicity of energy consumed by night workers but only during the summer (26) . A study on anthropometry and food intake patterns in bus drivers in Brazil reported higher proportions of inappropriate feeding practices, excess weight and abdominal obesity amongst drivers who worked night shifts (27) .…”

Risk factors for cardiovascular disease, metabolic syndrome and sleepiness in truck drivers

“…These findings were related to lifestyle, such as poor dietary habits and low physical activity 25 . Sleepiness in these subjects may be related to some factors, such as overtime work, poor sleep quality, illicit drug and alcohol intake and obesity.…”

Effects of irregular-shift work and physical activity on cardiovascular risk factors in truck drivers

“…However, few studies have investigated the health status of professional drivers. 15 Working irregular shifts contributes to unhealthy eating habits, 21 such as high calorie intake during nighttime meals.…”