• Journal of the Korean Dietetic Association
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• v.27 no.3
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• pp.179-190
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• 2021

The high caffeine intake by adolescents has been a concern. The purpose of this study was to examine the awareness and consumption of caffeine-containing foods among 443 high school students using a questionnaire. An analysis of the spending patterns of the students' weekly allowance showed that the amounts spent on purchasing caffeine-containing foods were higher for female students than male students (P <0.001). The scoring of the perception of caffeine was 3.1 out of 5, interest in the caffeine content of food was 2.6, consumption of caffeine-containing foods was 2.6, and usefulness of caffeine-containing foods was 2.7. The awareness of caffeine content in food was significantly higher in females (7.3 out of 11) than male students (6.7) (P<0.01). Approximately 59% of students perceived that the relationship between caffeine-containing foods and health, was harmful, and the experience of side effects after taking caffeine was significantly higher in female students than males. These side effects include heartburn (P<0.001), headache or dizziness (P<0.001), irregular heartbeat (P<0.05), and hands and feet shake (P<0.01). Caffeine-containing foods were purchased at convenience stores (62.1%). The factor considered when purchasing caffeine-containing foods was taste (72.2%), and the use of nutrition labeling for caffeine-containing foods scored 2.0 out of 5 points. When assessing the intake of caffeine-containing foods, the foods consumed more than once a week were in the order of coke, chocolate, chocolate milk, chocolate pie, and chocolate bars. These results suggest that it is necessary to prepare a caffeine-related nutrition guide improvement by sales management, and strengthen food labeling standards for the desirable recognition of caffeine and its safe intake by adolescents.

• Culinary science and hospitality research
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• v.6 no.3
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• pp.343-355
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• 2000

Caffeine is widely consumed ingredient and it belongs to alkaloids. Many foods that we intake contain caffeine ; coffee, tea cocoa, chocolate, and coke. And it is also added to many commercial remedies ; cold tablets, headache tablets, etc. Effect of caffeine that is known to us so far is as follows; 1. Remaining awake for long hours 2. Increasing concentration and decreasing fatigue 3. Increasing basal metabolic rate 4. decomposing glycogen and body fat and providing energy 5. Stimulating gastric acid 6. Increasing urinary excretion. Caffeine containing beverages(especially, coffee)are also favorite food in adult. In case of children and youth, chocolate and coke are favorite food. So, to intake caffeine containing foods moderately can be a vitality of life. But, a long-term intake or overdose of caffeine can result in many side effects. For example, headache, irritability, restlessness, hypertension, fetal abnormality, etc. Therefore, it is desirable that caffeine intake is under 300-400mg per day. To decrease intake of caffeine, 1. Use decaffeinated coffee 2. Product of decaffeinated coffee bean through gene transformation 3. Indicate content and function of caffeine on caffeine-food container 4. Provide an information of caffeine to public.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.650-662
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• 2014

This study was conducted to identify middle school students' caffeine intake from their favorite foods containing caffeine as well as several factors related to their intake. The objects of the investigation were 369 middle school students in the urban area of Changwon-si and 358 middle school students in the rural area of Haman-gun. The average height was 162.3cm, average weight was 52.3 kg and average BMI was 19.8. The food habit score was generally positive at an average of 3.37. The food habit scores of rural area students were higher than those of urban area students (p<.05). The average stress score was somewhat low at 2.82. The stress index for rural students was lower than that of urban students (p<.01). The recognition of caffeine in favorite foods was 8.12 out of a 12 point scale. The average nutritional knowledge score regarding caffeine was very low at 3.08 out of a 10 point scale. The main reason for selecting favorite foods was 'taste'. The percentage of students who don't check food labels was 49.1%. 'House' was the main location while 'good taste' was the biggest reason for eating caffeine-containing foods. The main side effect of caffeine intake was 'nausea'. The average daily caffeine intake for all subjects was 26.96 mg, with the urban students averaging 27.90 mg and the rural students averaging 25.99 mg. The correlations between several factors and caffeine intake were examined. Food habit showed a negative correlation with stress score and caffeine intake. Nutritional knowledge and recognition of caffeine had positive correlations with caffeine intake. Hence nutritional education about caffeine should be emphasized to improve students' healthy food habits.

• Journal of Nutrition and Health
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• v.43 no.5
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• pp.475-488
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• 2010

The daily caffeine intake from elementary school children's favorite foods was surveyed and evaluated. Children may respond to caffeine differently from adults because they have different physiological makeup and are functionally immature. Therefore, caffeine exposure may have more serious consequences for children than for adults, irrespective of sensitivity. Their preference, perception, and intake of caffeine from children's favorite foods were investigated by questionnaire for 355 children. The order of children's preference over foods containing caffeine was ice cream and ices, confectionary, milk and milk products, and soft beverage. The daily caffeine intake of children was estimated to range from 0.16 to 917.28 mg/day, with an average of $36.04\;{\pm}\;82.7$ mg/day and $36.9\;{\pm}\;96.0$ mg/day for boys and girls, respectively. The daily caffeine intake according to body weight was $1.08\;{\pm}\;2.23$ mg/kg and $1.12\;{\pm}\;2.66$ mg/kg for boys and girls, respectively. The percentage of acceptable daily intake (ADI) of caffeine was 43.4% for boys and 44.9% for girls. The sources of caffeine for boys and girls were soft beverage (18.3 mg and 16.1 mg), milk and milk products (8.9 mg and 8.5 mg), ice cream and ices (5.7 mg and 7.3 mg), chocolate (1.6 mg and 3.2 mg), and confectionery (1.6 mg and 1.8 mg).

• Journal of Korean Home Economics Education Association
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• v.26 no.4
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• pp.21-34
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• 2014

This study examined the levels of recognition, knowledge, and intake behavior of foods containing caffeine and analyzed the factors affecting amount of caffeine intake to get basic materials for development of educational program for proper intake behavior of foods containing caffeine of high school students in Gyeongbuk region. Of 300 questionnaires that were distributed on December 27, 2013 to February 14, 2014, 255 responses were used for analysis. Frequency distributions, Cronbach's ${\alpha}$, t tests, one-way ANOVA, Pearson's correlation analysis, and regression analysis were conducted by SPSS Windows V.21.0. The mean of the level of concern about foods containing caffeine was 2.76/5.00 points; male and second and third grade students showed lower concern level than female and first grade students. The respondents answered that intake of foods containing caffeine had somewhat harmful effect on health, but it did not much help to refresh and increase concentration. The mean for the percentage of correct answers about knowledge of caffeine was 54.3. Small number of the respondents were advised to reduce intake of caffeine from school teachers or parents. The average of caffeine intake amount was 71.67mg/day; the average for male was 78.98mg/day, whereas for female 61.23mg/day. Almost thirteen percentage of the respondents took caffeine over RDA(Recommended Daily Allowance). According to the result of regression analysis for amount of caffeine intake, grade, BMI, concern about health, perception of whether foods containing caffeine help with refreshment and increase of concentration or not, and experiences of having advice from school teachers to decrease caffeine intake were significant. These results imply that it is necessary for high school students to educate how to take caffeine properly.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.416-424
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• 2018

The physiologically advantageous aspects of green tea have been identified recently and green tea has been a favorite drink of many people. Due to the increased awareness of green tea's positive effects on human health, the demand for foods containing green tea has increased. This has led to the development of diverse green tea-related beverages; thereby many companies in Korea have put a wide variety of manufactured green tea beverages on the market. However, the components within green tea beverages have not been examined in Korea yet. In this study, we investigated the contents of the physiologically functional materials found in green tea, such as catechin, catechin gallate, epicatechin, epicatechin gallate, epigallocatecin gallate, gallocatechin gallate and caffeine. Fifty-six green tea products purchased from the local grocery stores and cafes were analyzed using high performance liquid chromatography (HPLC) analysis. As a result, all tested products contained catechin and caffeine, although the amount of each component was largely different. The total amount of catechin derivatives in the manufactured green tea beverages purchased from cafes was 263.17 mg/L, while they were 61.99 mg/L in the beverages purchased from the local grocery stores. And, to the almost samples the amount of caffeine was proportional to the amount of catechin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1128-1136
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• 2017

Previous studies of the caffeine consumption pattern were limited primarily to beverages containing caffeine. Therefore, this study examined the caffeine consumption patterns and levels in beverages and foods containing caffeine among high school students (n=310) in the Yongin region. The participants included 171 boys (55.2%) and 139 girls (44.8%). The daily mean caffeine intake of the respondents was 41.27 mg (0.651 mg/kg) and 36.47 mg (0.696 mg/kg) in boys and girls, respectively. Among the caffeinated food groups, coffee had the highest caffeine intake group in both boys (18.95 mg) and girls (26.28 mg). Girls consumed large amounts of caffeine in the form of Americano-style coffee (20.04 mg), whereas boys consumed more canned coffee (6.77 mg) than girls (2.43 mg, P<0.01). Carbonated soft drinks were the second most prevalent source of caffeine intake in both groups, even though boys (14.29 mg) consumed larger amounts of caffeine than girls (5.85 mg, P<0.001). Multiple regression analysis investigating the major contributing food group to daily total caffeine intake also showed that the highest standardized coefficient was in coffee regardless of gender (boys 0.492, P<0.001 and girls 0.944, P<0.001), followed by carbonated soft drinks and energy drinks. Approximately 95% of high school students consumed normal levels of caffeine, whereas 3.5% of boys and 5.8% of girls consumed excessive amounts based on the standard limit of Korea Food and Drug Administration (<2.5 mg/kg/d) for adolescents. The daily mean caffeine intake of the excess group was 5.38 mg/kg and 6.96 mg/kg in boys and girls, respectively. Consequently, safe daily caffeine intake needs to be determined throughout continuous national management guidelines and nutritional education.

• Korean Journal of Community Nutrition
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• v.10 no.3
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• pp.271-280
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• 2005

The purpose of this study was to investigate fast-food consumption and it's nutrient density, and the correlation between subject's characteristics and consumption frequency of fast-foods among middle school students. The questionnaires were distributed to 150 male and 190 female students in Cheongju city. The data were analyzed using SAS and statistics used were percent of frequency, $X^2$-test, t-test, and pearson's correlation coefficient. The main reasons for using fast-food restaurants were 'good taste' and 'convenience'. The major concerns when the subjects choose fast-foods were 'taste ($65.9\%$), price ($20.3\%$) and 'nutrition'($6.0\%$). The consumption pattern of fast-foods go as follows: twice a month ($42.3\%$), once a week ($31.5\%$), and less than once a week. The number of fast food items that the subjects ate for one meal was two ($46.0\%$) or three ($33.2\%$). The most frequently chosen combination of foods for number of two choices was beefburger and cola. The mean average energy intake from fast foods for one meal was 620.7 kcal for male, 504.5 kcal for female. The energy ratio of carbohydrate : protein fat from fast foods was 49 : 14 : 43, which means fat intake is much higher than recommended level ($20\%$). Fiber was appeared to be the lowest on the nutrient density which was $17.7\%$ of the recommended level for Koreans, vitamin C was next ($22.8\%$ for male, $20.1\%$ for female). In mineral, iron was the lowest ($71.8\%$ for male, $67.1\%$ for female), and protein was over $100\%$ for both males and females. Frequency of fast food intake was positively correlated with eating frequency of the salty, the sweets, him, caffeine containing foods, instant noodles, and cookies. In conclusion, frequent consumption of fast foods can lead unbalanced nutrient intakes for middle school students, and those who consumed fast foods frequently showed undesirable food habits in their daily meal. Therefore, nutrition education for middle school students should be needed to encourage them to choose more nutritious food and have healthier dietary pattern.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.61-71
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• 2024

In this study, we analyzed chlorogenic acid indicator components in preparation for the additional listing of green coffee bean extract in the Health Functional Food Code and optimized caffeine for simultaneous analysis. We extracted chlorogenic acid and caffeine using 30% methanol, phosphoric acid solution, and acetonitrile-containing phosphoric acid and analyzed them at 330 and 280 nm, respectively, using liquid chromatography. Our analysis validation results yielded a correlation coefficient (R²) revealing a significance level of at least 0.999 within the linear quantitative range. The chlorogenic acid and caffeine detection and quantification limits were 0.5 and 0.2 ㎍/mL and 1.4, and 0.4 ㎍/mL, respectively. We confirmed that the precision and accuracy results were suitable using the AOAC validation guidelines. Finally, we developed a simultaneous chlorogenic acid and caffeine analysis approach. In addition, we confirmed that our analysis approach could simultaneously quantify chlorogenic acid and caffeine by examining the applicability of each formulation through prototypes and distribution products. In conclusion, the results of this study demonstrated that the standardized analysis would expectably increase chlorogenic acidcontaining health functional food quality control reliability.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.419-429
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• 2022

Water accounts for the largest proportion of body weight and is an essential element for the physiological functioning of the human body. According to 2013-2017 Korea National Health and Nutrition Examination Survey (KNHANES) data, the average water intake of Koreans was 2,167.3 mL/day and 62% of them did not meet the Dietary Reference Intakes for Koreans (KDRIs) for water. However, the consumption of beverages is continuously increasing. KDRIs sets the adequate intake (AI) for water, but tolerable upper intake level (UL) and chronic disease risk reduction intake (CDRR) are not provided. Compared to 2015, the AI of total water from both food and fluids in the 2020 KDRIs slightly increased or decreased according to age. The AI for children 1-2 years old, boys 6-8 years and 9-11 years old, and girls 6-8 years old decreased by 100 mL/day, while that of boys 12-14 years old increased by 100 mL/day. The AI of total water was the sum of the water intake from food and fluids reported by the KNHANES, with an extra milk intake of 200 mL/day. Therefore, it is not appropriate to use the AI of total water intakes for the reference of beverage intakes. It is preferable to consume water or milk rather than beverages containing sugar and others including caffeine, sodium, etc. when drinking fluid water. We suggest the following improvements in the future KDRIs for water: improving the adequacy of the water content ratio of Korean conventional foods, supplementing the fluid water intake survey, reflecting the current water intake status by life cycle, setting KDRIs for water for the elderly considering the physiological changes, health status and dietary habits, and promotion of research on the relationship between water intake and health for Koreans.