Journal List > J Nutr Health > v.49(5) > 1081461

J Nutr Health. 2016 Oct;49(5):367-377. Korean.
Published online October 31, 2016.
© 2016 The Korean Nutrition Society
Relationships between job stress and caffeine intake in industrial workers
Ji-Suk Yim,1 and Jae-Joon Lee2
1Department of Food and Nutrition, Chonnam National University, Gwangju 61186, Korea.
2Department of Food and Nutrition, Chosun University, Gwangju 61452, Korea.

To whom correspondence should be addressed. tel: +82-62-230-7725, Email:
Received August 09, 2016; Revised August 29, 2016; Accepted September 06, 2016.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.



This study analyzed the degree of job stress and caffeine intake in workers in industrial positions in order to determine the relationships between job stress and caffeine intake.


For this purpose, this study conducted a survey targeting 361 blue collar workers working for K manufacturing company, Gwangju.


The total score for job stress in subjects was 72.7 ± 6.8 points/100 points. According to job stress, subjects were categorized as follows: Q1 for the group who had the least stress; Q2 for the group who had little stress; Q3 for the group who had a lot of stress, and Q4 for the group who had the most stress. As for the effects of caffeine on health, 57.1% thought that caffeine is helpful and not harmful if taken properly while 17.3% responded that less caffeine consumption is better. Daily intake of caffeine according to stress was presented as: 172.0 ± 85.3 mg in Q1, 179.0 ± 83.7 mg in Q2, 187.9 ± 81.4 mg in Q3, and 214.2 ± 147.3 mg in Q4 (p < 0.05). The percentages of caffeine consumption compared to the daily safe limit in subjects were: 43.0 ± 21.3, 44.8 ± 20.9, 47.1 ± 20.4, and 53.6 ± 36.8% in Q1, Q2, Q3, and Q4, respectively (p < 0.05). Adverse effects such as nausea or vomiting from caffeine were most common in Q4 (p < 0.05)


As a result, higher stress in blue collar workers working for K manufacturing company was associated with more caffeine consumption. Groups with a lot of stress (Q4) consumed approximately 50% of daily safe limit of caffeine. Considering the results above, this study suggests that further research on more precise caffeine intake and its effects is needed.

Keywords: caffeine intake; degree of job stress; male blue collar workers


Table 1
General characteristic of subjects n (%)
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Table 2
Job stress degree
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Table 3
Anthropometry investigation according to the job stress levels n (%)
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Table 4
Healthy behaviors according to the job stress levels n (%)
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Table 5
Caffeine awareness according to the job stress levels n (%)
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Table 6
Caffeine intake according to the job stress levels
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Table 7
Adverse effects from caffeine intake according to the job stress levels
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Table 8
Pearson's correlation coefficients between caffeine intake and general characteristics of subjects
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