• Korean Journal of Community Nutrition
• /
• v.25 no.6
• /
• pp.485-501
• /
• 2020

Objectives: The purpose of this study was to examine the biochemical characteristics and dietary intake of adolescents aged 12 to 18 years according to the frequency of milk consumption. Methods: Data from the 2010~2011 Korea National Health and Nutrition Examination Survey was used for the study. The study examined adolescents' (12~18 years) demographic characteristics (house income level, residence region, skipping or not-skipping of breakfast/lunch/dinner, eating-out frequency), anthropometric characteristics (height, weight, weight status), biochemical characteristics (fasting plasma glucose, blood urea nitrogen, creatine, triglycerides, cholesterol, HDL-cholesterol, hemoglobin, hematocrit) and nutrient intakes through quantitative and qualitative evaluation using the Korean Dietary Reference Intakes (KDRI), index of nutrition quality (INQ), nutrition adequacy ratio (NAR) of 3 groups (< 1/week, 1~6/week, ≥ 1/day) according to the frequency of milk consumption. Results: There were significant differences in gender and income levels among the 3 groups. There were no differences in height, weight, and weight status among groups. There were differences in biochemical characteristics and nutrient intake. In boys, there were differences in the mean of BUN and HDL-cholesterol, in quantitative intakes of riboflavin, calcium, phosphorus, potassium by KDRI levels, in qualitative intakes of riboflavin, calcium, phosphorus by INQ and riboflavin, calcium, phosphorus by NAR among 3 groups. In girls, there were differences in the mean of blood urea nitrogen, creatine, HDL-cholesterol, in quantitative intakes of protein, riboflavin, calcium, phosphorus by KDRI levels, in qualitative intakes of riboflavin, calcium, phosphorus by INQ and riboflavin, calcium, phosphorus by NAR among the 3 groups. Conclusions: In Korean adolescents, boys had a higher frequency of milk consumption than girls, and higher the income level, higher the frequency of milk consumption. Consumption of milk appeared to have a positive association with triglycerides, HDL-cholesterol, and indices related to muscle mass. Regular consumption of milk is an important factor in enhancing the intake of riboflavin, calcium, and phosphorus, which adolescents lack. The results of the study indicate a need to prepare an environment and education program to increase milk consumption in adolescents at home and school.

• Korean Journal of Community Nutrition
• /
• v.13 no.4
• /
• pp.476-488
• /
• 2008

This study investigates the relationship of smoking on daily intake of nutrients and snacks in the Chungnam and Daejeon high school students. Up to date scientific nutrition education and counseling programs in the regular school system is needed for a professional nutrition education teacher. The primary objective of this study was to provide useful information to nutrition education teachers. A survey was conducted with 400 high school students in the Chungnam and Daejeon areas. 381 out of 400 questionnaires were analyzed with SPSS 12.0K. The subjects were composed of 49.8% male, 50.1% female and 40.9% regular high school students, 59.1% business high school students and smokers 43.1%, non-smokers 56.9%. 43.4% of smokers had been smoking since middle school. On analysis of daily nutrient intakes, 16 out of 19 nutrients except animal calcium, Vitamin A and Vitamin C were much more consumed by the smoking group than the non-smoking group non-significantly. Especially vegetable fat and Vitamin E were higher in the smoking group than the non-smoking group (p<0.05). The intake ratio of carbohydrates: protein: fat was similar in the two groups (smoking group 55:15:29, nonsmoking group 56:15:28). Intakes of Vitamin B1 and potassium in comparison with the Korean dietary reference intakes(KDRI) were under 50% in both groups. However, sodium was taken over 200% compared to KDRI in both groups. Intakes of Vitamin C in the smoking group were as low as 76.5% in comparison to KDRI. Smokers need to increase the intakes of Vitamin C considering that smokers need to intake Vitamin C two times than non-smokers. Nutrient intakes from snacks in the smoking group were higher than the non-smoking group. Nutrients that originated from snacks which took over 20% among daily nutrient intakes were 12 nutrients(energy, fat, carbohydrate, calcium, P, Fe, K, Vitamin $B_1$, Vitamin $B_2$, Vitamin C, Vitamin E, dietary fiber) in the smoking group compared to 7 nutrients(energy, vegetable protein, fat, carbohydrate, calcium, Vitamin $B_2$, Vitamin C) in the non-smoking group. The smoking group was significantly paying more money for snacks each month than the non-smoking group was(p<0.01). Periods of consumption were irregular in the smoking group(p<0.05) and the smoking group was used to taking snacks in the morning compared to the non-smoking group. The smoking group preferred sweets and high calorie food over other snacks in comparison of the non-smoking group. The nonsmoking group had better eating habits than the smoking group.

• Journal of Nutrition and Health
• /
• v.55 no.5
• /
• pp.523-532
• /
• 2022

Vitamin C is an important physiological antioxidant which neutralizes reactive oxygen species (ROS) and reduces the oxidative stress in the body. Although it has been associated with various diseases, few studies have reported the dose-response relationship between vitamin C intake, storage and functions in the body, including its antioxidant function. The criteria to establish the Dietary Reference Intakes for Koreans (KDRIs) for vitamin C were based on the changes in plasma concentrations and saturation of leukocytes according to intake levels and the effects on antioxidant capacity and risk of metabolic diseases. When establishing the 2020 vitamin C KDRI, while there was no change in the criteria from those of 2015, the reference values were recalculated and revised to reflect changes such as the new standard weight by age. As the number of people consuming dietary supplements has increased over the last decade, only about 10% of adults consume less than the average total vitamin C, but the proportion of adolescents and elderly who consume less than the average is high. On the other hand, as the intake of vitamin C supplements increases, the proportion of people consuming excessive vitamin C is also increasing. There is a body of opinion that it is necessary to establish a vitamin C KDRI for smokers or people with chronic diseases such as the metabolic syndrome, but these standards have not been established due to the lack of supporting scientific evidence. As a result, studies to establish vitamin C KDRI for Korean smokers and patients with the metabolic syndrome, as well as studies on the excessive intake of vitamin C due to supplementation and interactions with other nutrients, are needed.

• Journal of Nutrition and Health
• /
• v.42 no.4
• /
• pp.327-337
• /
• 2009

University students tend to have various dietary problems including undesirable dietary behaviors, inadequate intakes of nutrients and biased habits of liquid consumption. This study was conducted to find dietary behaviors (n = 357) by questionnaire survey and to examine dietary nutrient intakes (n = 60) and liquid consumption (n = 853) by food record method for 3-days among university students attended in K University of Chungnam province in Korea. Most subjects lived in the dormitory or self-boarding house, and they skipped breakfast most frequently and took breakfast most irregularly among three meals. Dietary mean intakes of energy, Ca, vitamin B2 and folate were lower than the KDRI (37-85%), and those of males were poorer than those of females. Ratios of energy intake among three meals and snacks were not distributed evenly, so the mean energy intake from snacks was higher and that from breakfast was lower than the ideal ratio, respectively. Daily mean consumption of liquid was 1,526.4 mL/d for males and 1,151.5 mL/d for females, and these intakes were more than the KDRI (1,300 mL/d for males and 1,100 mL/d for females). However, their sources of liquid consumption were not desirable because alcohol, soda, juice of fruit or vegetable and beverage mixed with fruit juice and/or vegetable juice were major sources of liquid as well as drinking water. These findings show that university students have poor dietary behaviors including frequent skipping of breakfast, irregularity of meals, inadequate intakes of nutrients and undesirable pattersirablliquid consumption including high portion of alcohol and soda as alliquid source, and these trends were stronger for males than for females. Therefore, we should endeavor to correct their meal problems id ated to dietary behaviors, nutrient intakes and liquid consumptions through nutrition education.

• Nutrition Research and Practice
• /
• v.16 no.2
• /
• pp.233-247
• /
• 2022

BACKGROUND/OBJECTIVES: The objective of this study was to describe the development process of the Korean Healthy Eating Index (KHEI) based on the Korea National Health and Nutrition Examination Survey (KNHANES). SUBJECTS/METHODS: The components of KHEI were selected based on Dietary Guidelines for Koreans, domestic and overseas dietary quality indices, and results of the analysis of association with chronic diseases. The standards for scoring of KHEI were selected based on the 2015 Dietary Reference Intakes for Koreans (KDRI). The KHEI scores of Korean adults were calculated using a 1-day 24-h recall data in the 2013-2015 KNHANES. RESULTS: The KHEI included eight adequacy components evaluating the proper intake of recommended foods such as fruit, vegetable, and milk and three moderation components evaluating the consumption of food that limit intake such as sodium and saturated fatty acid. In addition, three balance components assessing the balance of energy intake were included. The KHEI score was defined to range from the minimum of 0 point to the maximum of 100 points. Among Korean adults, the total KHEI score was 63.2 out of 100. Gender and age differences were found in the average of total KHEI scores. Women showed higher score than men (61.7 in men and 64.7 in women, respectively). By age group, 20s and 30s showed the lowest scores with 57.4 and 61.1 respectively, and the scores increased with age by peaking at 67.8 in ages 60-69 and slowed down again in ages 70 or over. CONCLUSIONS: The KHEI can be useful for establishing and assessing national nutritional policies and in epidemiological studies to assess the relationship between overall dietary quality and chronic diseases. KHEI will need to be continuously updated to reflect changes in dietary guidelines and the KDRI.

• Nutrition Research and Practice
• /
• v.16 no.sup1
• /
• pp.57-69
• /
• 2022

BACKGROUND/OBJECTIVES: Vitamin D is produced in the skin during sun exposure and is also ingested from foods. The role of vitamin D needs to be considered in the prevention and management of various diseases. Moreover, since the majority of Koreans spend their days indoors, becoming susceptible to the risk of vitamin D deficiency. The current study aims to prepare a basis for determining dietary reference intake of vitamin D in Korea, by reviewing the evidence against various diseases and risks. MATERIALS/METHODS: Literature published in Korea and other countries between 2014 and 2018 was prioritized based on their study design and other criteria, and evaluated using the RoB 2.0 assessment form and United States Department of Agriculture Nutrition Evidence Library Conclusion Statement Evaluation Criteria. RESULTS: Of the 1,709 studies, 128 studies were included in the final systematic analysis after screening. To set the dietary reference intakes of vitamin D based on the selected articles, blood 25(OH)D levels and indicators of bone health were used collectively. Blood vitamin D levels and ultraviolet (UV) exposure time derived from the Korean National Health and Nutrition Examination Survey were analyzed to establish the dietary reference intakes of vitamin D for each stage of the life cycle. The adequate intake levels of vitamin D, according to age and gender, were determined to be in the range of 5-15 ㎍/day, and the tolerable upper intake level was established at 25-100 ㎍/day. CONCLUSIONS: The most important variable for vitamin D nutrition is lifestyle. A balanced diet comprising foods with high contents of vitamin D is important, as is vitamin D synthesis after UV exposure. The adequate intake level of vitamin D mentioned in the 2015 Dietary Reference Intakes for Korean (KDRI) remained unchanged in the 2020 KDRI for the management of vitamin D nutrition in Koreans.

• Nutrition Research and Practice
• /
• v.16 no.sup1
• /
• pp.11-20
• /
• 2022

Research articles were reviewed to validate the estimated energy requirements (EERs) equations developed by the Institute of Medicine of the National Academies (IOM). These equations are based on total energy expenditure (TEE) measured by the doubly labeled water (DLW) method. We subsequently aimed to provide the basis for the suitability to apply the IOM equations as EER equations for Koreans, and develop relevant equations for EER in the Dietary Reference Intake for Koreans (KDRI). Additionally, besides the EER(IOM) equations, other equations were examined for EER estimation. Research papers demonstrating the validation of the EER(IOM) equations based on TEE(DLW) were searched through PubMed (up to September 2019). Of the 637 potentially relevant articles identified, duplicates and unsuitable titles and abstracts were excluded. Furthermore, papers with irrelevant subject and inappropriate study design were also excluded. Finally, 11 papers were included in the review. Among the reviewed papers, 8 papers validated the application of the EER(IOM) equations for EER based on TEE(DLW). These included 3 studies for children (USA 1, Korea 2), 1 for adolescents (Portugal), 2 for adults (Korean), and 2 for the elderly (Korea, USA). EER(IOM) equations were found to be generally acceptable for determining EER by using the DLW method, except for Korean boys at 9-11 yrs (overestimated) and female athletes at 19-24 yrs (underestimated). Additionally, 5 papers include the validation of other EER equations, beside EER(IOM) for EER based on TEE(DLW). In Japanese dietary reference intake and recommended dietary allowance, EER equations are acceptable for determining EER based on TEE(DLW). The EER(IOM) equations is generally acceptable for determining EER using the DLW method in Koreans as well as several populations, although certain defined groups were found to be unfit for the estimation. Additionally, the concept of healthy body mass index of Koreans and physical activity levels need to be considered, thereby providing the basis for developing relevant equations of EER in KDRI.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.43 no.1
• /
• pp.43-52
• /
• 2017

EtOAc fractions of Magnolia obovata (M. obovata) Bark extracts were studied for the potential ingredient as a safe and effective whitening cosmetic material. The concentration of active substances honokiol was determined by HPLC. In vitro, the fractions reduced the extracellular and intracellular melanin contents in B16F10 cells in dose dependently and inhibited extracellular melanin secretion ($IC_{50}=11.05{\mu}g/mL$). The $12.5{\mu}g/mL$ treatment of maximum concentration effectively inhibited up to about 60% to the amount of extracullular melanin. Also, the $12.5{\mu}g/mL$ treatment of maximum concentration effectively inhibited up to about 59% to the amount of intracullular melanin ($IC_{50}=10.85{\mu}g/mL$). The $IC_{50}$ value of ${\alpha}-arbutin$ used as a positive control was $59.99{\mu}g/mL$. So, EtOAc fractions of M. obovata Bark extracts showed whitening effect when compared with the non-treatment group. In case of in vivo study, Cosmetic cream with EtOAc fractions of M. obovata Bark extracts was approved by Ethics committee of KDRI (IRB number: KDRI-IRB-1537). As a result in progress for skin sensitization as well as assessment of skin irritation through repeated patch test, skin allergens was identified as non sensitizing agents. Also, cosmetic cream with EtOAc fractions of M. obovata Bark extracts showed significant topical whitening effect and reliable skin safety when compared with the non-treatment group. In conclusion, EtOAc fractions of M. obovata Bark extracts may be a useful cosmetic ingredient for effective skin whitening.

• Journal of Nutrition and Health
• /
• v.55 no.2
• /
• pp.211-226
• /
• 2022

Choline, an essential nutrient for humans, is required for the structural integrity of the cell membranes, methyl-group metabolism, synthesis of the neurotransmitter acetylcholine, synthesis of the membrane phospholipid components of the cell membranes, and the transport of lipids and cholesterol. Choline can be synthesized in the body, but it is insufficient to meet the daily requirements and hence it must be obtained through the diet. In the United States/Canada, Australia/New Zealand, Europe, China, and Taiwan, the adequate intake (AI) and tolerable upper intake level (UL) of choline have been established, while the establishment of the 2020 Dietary Reference Intakes for Koreans (KDRI) for choline was postponed due to the lack of a choline database for Korean foods and studies on the choline intake of Koreans. However, as part of the preparation work for the 2020 DRI revision and finalization, choline intake and the possibility of disease occurrence were verified through analysis of published data. The groundwork for the subsequent establishment of a choline DRI was laid through a literature search, evaluation, and review of the literature reported from 1949 up to 2019. This can be regarded as the culmination of this project. According to the results of randomized controlled trials (RCTs), cohort studies, case-control studies, and cross-sectional observational studies in humans, approximately 400-500 mg/day of choline intake was effective in preventing liver function damage (fatty liver), neural tube damage, cardiovascular disease, breast cancer, and cognitive function improvement. The same amount of choline intake, however, also correlated with the risk of prostate and colorectal cancer. At present, there is limited information available on choline intake and health outcomes, particularly for the Korean population. More human studies, including clinical trials on the requirements and the physiological benefits associated with dietary intake, are needed to establish the KDRI for choline.

• Journal of Nutrition and Health
• /
• v.56 no.6
• /
• pp.730-741
• /
• 2023

Purpose: The 2020 Dietary Reference Intakes for Koreans (KDRIs) serves as a foundation for daily nutrient and energy recommendations aiming to enhance public health and prevent chronic diseases. They act as guidelines for maintaining proper nutrition and overall health. Using KDRIs is crucial for promoting healthier lifestyles and making informed dietary choices. Thus, this study explores the influence of a nutrition education program, based on the 2020 KDRIs, on the nutrition knowledge and dietary habits of undergraduates in Gyeongsangnam-do and Gyeonggi-do. Methods: The nutrition education program, designed with diverse instructional materials, was executed across a wide range of universities. The education group (n = 75) engaged in the program for a 6-week instructional period, while the control group (n = 53) underwent the survey without participating in the education program. Nutrition Quotient (NQ) and knowledge assessments were administered to both groups immediately before and after the instructional period. Results: Within the education group, the nutrition education program positively impacted responses to NQ practice items, including knowledge of nutrition, daily intake, and portion sizes (p < 0.05). In contrast, there were no significant differences between the before and after responses of the control group for most survey items. Post-program evaluations showed significantly higher self-assessment scores and increased satisfaction levels (p < 0.05), with the satisfaction rate for the education program using the 2020 KDRIs reaching 99.2%. Conclusion: This study has demonstrated the positive impact of an effective nutrition education program. However, there is a need for the continuous development and implementation of nutrition education programs to sustain these outcomes and further enhance the nutritional education experience.