Due to the prohibitions of selling soft drinks in school and a sharp increase in the number of coffee shops recently, there is concern about teen''s high caffeine intake caused by eating junk foods and fancy drinks too much. The purpose of this study is to investigate the daily amount of caffeine intakes from middle school students, and to investigate perceptions of caffeine-contained beverages, eating habits, and life habits. For this study 249 middle school students in Deajeon city at two regions in December 2012 participated. Analysis data of Kim et al (2009), Lee et al (2007), and Korea Food and Drug Administration (2011) were used for standard values for this study. Subjects were 51.8% males and 48.2% females, and 32.1% first, 32.9% second, and 34.9% third grades attending middle school.
Caffeine consumers'' intakes were 33.30±39.11mg caffeine per day, that was less than the amount of caffeines intake from Korea Food and Drug Administration (2.5mg/kg body weith/day), however higher than the amount of caffeine intake in high school students in 2010. Major sources of caffeine were coffee from coffee machine (7.23±15.85mg/day), and caffeine intakes for male in the canned coffee (p<.01) and energy drinks (p<.01) were higher than female. The average score of perception of caffeine-contained beverages was 12.38±1.83, the lowest drinks of perception of caffeine-contained beverages was powered cocoa drinks (34.1%). The average of perception of caffeine overdose was 6.30±1.37, there was not statistically significant difference between males and females, and there were negatively correlated with perception of caffeine overdose and amount of caffeine intake (r=-0.220, p<.01).
The most popular answer of an available place to drink the caffeine-contained beverages was ''home (51.8%)'' in males and females, the second answer of an available place to drink was ''shops near the private educational institute'' in males, ''shops near the school'' in females. The average of recognition of food ingredient labelling in adolescents was 2.31±1.12 of 5, the higher recognition of food ingredient labelling related to the lower amount of caffeine intake.
The amount of caffeine intake in adolescents related to lower level of mother''s educational level (less than a high school graduate vs. higher than a college graduate, p<.001), and related to more purchasing beverage (p<.001). And the amount of caffeine intake in adolescents related to longer hours in after school learning (p<.05), related to longer hours in watching TV (p<.05), and using computer (p<.01).
The better eating habits related to the lower amount of caffeine intake (r=-0.204, p<.01), and there were positively correlated with poor eating habits and amount of caffeine intake (r=0.322, p<.001).
The results from this study implication are that guide to drink preference and recognition of food ingredient labelling are necessary in school and home as well.