• Nutrition Research and Practice
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• v.10 no.4
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• pp.448-455
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• 2016

BACKGROUND/OBJECTIVES: A growing body of research has indicated that night eating could be associated with poor diet quality and negative health outcomes. This study examined the nutritional aspects of night eating, its related factors, and the association between night eating and body weight among Korean adolescents. SUBJECTS/METHODS: This study analysed the data from a one day 24-hour dietary recall as well as a demographic survey of 1,738 Korean adolescents aged 12 to 18-years-old obtained from the 2010-2012 Korea National Health and Nutrition Examination Survey. 'Night eating' was defined as consuming 25% or more of one's daily energy intake between 21:00 and 06:00. Subjects complying with the preceding condition were classified as 'night eaters', whereas the rest were considered 'non-night eaters'. Logistic regression analysis examined factors related to night eating. Multiple linear regression analyses were used to examine the relationship between night eating and BMI z-scores, whereas multinomial logistic regression analysis was used to examine the relationship between night eating and weight status. RESULTS: About 21% of Korean adolescents appeared to be night eaters. Night eaters showed increased breakfast skipping (P = 0.001), higher energy intake from snacks (P < 0.001), greater proportion of energy intake from fat (P = 0.029), and lower Dietary Diversity Scores (P = 0.008) than non-night eaters. Male adolescents presented 1.9 times higher odds of being night eaters than females. Adolescents whose both parents were night eaters were 4.4 times as likely to be night eaters as those whose neither parents were. Female adolescents showed a significant relationship between night eating and BMI z-scores (${\beta}=0.28$, P = 0.004). However, night eating did not increase odds of being overweight or obese in adolescents. CONCLUSIONS: Night eating in Korean adolescents was related to undesirable dietary behaviours and low diet quality in general as well as higher BMI z-scores in females. Male gender and parental night eating appeared to be the factors that significantly increased odds of night eating. These results suggest that night eating should be considered when designing nutrition education or intervention programs targeting adolescents.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.125-133
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• 2016

Purpose: The purpose of this study is to analyze nutrient intake and frequently consumed foods according to the intake frequency of Baechu (Chinese cabbage) kimchi by Korean adults. Methods: Data from analysis of 7,122 subjects aged 19~64 years from 2012, 2013 KNHANES were obtained from health behavior interviews and the 24-hour dietary recall method. Results: With the daily intake frequency of Baechu kimchi, subjects with two times a day were the highest proportion among total subjects. As Baechu kimchi intake frequency of breakfast, lunch, and dinner increased, the rate of skipping meals decreased significantly (p < 0.05). In addition, all food intake and daily nutrient intake increased significantly with increasing frequency of daily Baechu kimchi intake (Crude p for trend < 0.05, Adjusted p for trend < 0.05). With the frequently consumed foods by daily Baechu kimchi intake frequency in 2012 and 2013, among 509 foods top ranked foods were white rice, Baechu kimchi, beer, distilled alcoholic drink, milk, and pork. Conclusion: The results of this study could be used in the future to promote consumption of kimchi in the Korean population.

• Journal of Nutrition and Health
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• v.43 no.6
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• pp.638-652
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• 2010

A valid food or dish frequency questionnaire needs to be developed in Korea for accurate dietary assessment because the dietary practices of Koreans are very different from those of other countries. This study was conducted to evaluate the accuracy of the newly developed, semi-quantitative, dish-based frequency questionnaire (Semi-DFQ) with 12-day dietary records (12-DRs) as a gold standard. The study subjects were 115 men and 173 women aged 30-65 years old. We calibrated the frequency, portion size and daily intake of 112 dish items reported in Semi-DFQ with those in 12-DRs by Spearman rank correlation coefficients (SCCs). The consumption frequency and portion size reported in Semi-DFQ were higher than those in 12-DRs. The SCCs for the consumption frequency of various dishes ranged from -0.07 (fried seaweed) to 0.70 (instant coffee), the portion size ranged from -0.09 (cold seaweed soup) to 0.68 (soju), and the daily intake ranged from -0.07 (fried seaweed) to 0.71 (soju). The SCCs were higher for dishes consumed daily, such as steamed rice,milk, coffee and alcohol, than those of foods eaten rarely. The overall agreements between the Semi-DFQ and 12-DRs were low for categories of consumption frequency and portion size, even though some dishes showed high SCCs. The SCCs of the two methods in consumption frequency and amount were higher among the women and younger subject. The results revealed the limitation of the Semi-DFQ for evaluating the status of usual individual intake. Therefore, the Semi-DFQ can be used in addition as dietary records and 24-hour recall depending on the research aims.

• Journal of Nutrition and Health
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• v.46 no.1
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• pp.61-71
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• 2013

The aim of this study was to examine the relationship between dietary variables and the prevalence of insulin resistance (IR) in middle-aged Korean adults using data from the 2007-2009 Korea National Health and Nutrition Examination Survey. Because IR is closely linked with metabolic syndrome, subjects were divided into three groups according to symptoms of metabolic syndrome: the 'Normal group' without any symptoms, the 'Risk group' with one or two symptoms, and the Metabolic syndrome (MetS) group' with three or more symptoms. Subjects between the ages of 30 and 65 years with no prior diagnosis or treatment for diabetes, hypertension, or dyslipidemia were selected. The number of subjects per group was as follows: 2,085 adults in the Normal group, 3,699 adults in the Risk group, and 1,160 adults in the MetS group. Metabolic syndrome was defined according to Adult Treatment Panel III criteria with modified waist circumference cutoff values (men ${\geq}$ 90 cm, women ${\geq}$ 85 cm). Subjects with HOMA-IR > 2.0 were classified as IR. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated using the following formula: (fasting plasma glucose ${\times}$ fasting plasma insulin)/22.5. Nutrients and food groups intake were obtained from a single 24-hour recall. Subjects with IR in the Normal group were more obese and less physically active than non-IR subjects. In the MetS group, subjects with IR were more obese and had a lower prevalence of smoking and drinking, compared with non-IR subjects. Men with IR in the Normal group had a tendency to consume more oils and sugars than non-IR men, while women with IR in the same group had higher intake of carbohydrate, dietary glycemic index, and dietary glycemic load than non-IR women. Women with IR in the Risk group had lower energy intake but higher intake of oils and sugars than non-IR women. In the MetS group, consumption of fruits was higher in subjects with IR than in non-IR subjects. In conclusion, findings of this study suggest that dietary carbohydrate intake, including glycemic index, may be associated with IR in healthy women. Further research in prospective cohort studies in order to examine the effects of dietary carbohydrate on IR incidence will be necessary.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.304-312
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• 2016

Purpose: The purpose of the study was to investigate the association between food intakes and cardiovascular disease (CVD) risk factors in Korean women with type 2 diabetes mellitus (T2DM). Methods: The data were collected from the 2007~2012 Korea National Health and Nutrition Examination Survey (KNHANES). In this study, subjects were divided into two groups, the normal fasting glucose (NFG) group (n = 7,738) and the T2DM group (n = 225). Dietary intake was derived from the nutrition survey, which was collected by trained dietitians using 24-hour dietary recall through the face-to-face interview method in the sample person's home. Results: After adjustment for confounding factors, mean fruit (p = 0.0265), fruit and vegetable without kimchi (p = 0.0295), and fish (p = 0.0112) intakes were significantly lower in the T2DM group than in the NFG group. In the multiple logistic regression analysis, odds ratio (OR) for risk of high systolic blood pressure (${\geq}140mmHg$) was lower in the over the median compared to under the median for fruit intakes (OR; 0.657, 95% CI; 0.523~0.824). The OR for the risk of hypertriglyceridemia was lower in the over the median compared to under the median for fruit and vegetable without kimchi (OR; 0.828, 95% CI; 0.7111~0.963) and fish (OR; 0.783, 95% CI; 0.673~0.910) intakes. Conclusion: These results show that intakes of fruits, fish, and fruits and vegetables without kimchi have beneficial effects on CVD in Korean women with T2DM.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.650-657
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• 2015

BACKGROUND/OBJECTIVES: The aim of this study was to estimate average total fat and fatty acid intakes as well as identify major food sources using data from the Korea National Health and Nutrition Examination Survey (KNHANES) VI-1 (2013). SUBJECTS/METHODS: Total fat and fatty acid intakes were estimated using 24-hour dietary recall data on 7,048 participants aged ${\geq}3years$ from the KNHANES VI-1 (2013). Data included total fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), n-3 fatty acid (n-3 FA), and n-6 fatty acid (n-6 FA) levels. Population means and standard errors of the mean were weighted in order to produce national estimates and separated based on sex, age, income, as well as residential region. Major food sources of fat, SFA, MUFA, PUFA, n-3 FA, and n-6 FA were identified based on mean consumption amounts of fat and fatty acids in each food. RESULTS: The mean intake of total fat was 48.0 g while mean intakes of SFA, MUFA, PUFA, n-3 FA, and n-6 FA were 14.4 g, 15.3 g, 11.6 g, 1.6 g, and 10.1 g, respectively. Intakes of MUFA and SFA were each higher than that of PUFA in all age groups. Pork was the major source of total fat, SFA, and MUFA, and soybean oil was the major source of PUFA. Milk and pork were major sources of SFA in subjects aged 3-11 years and ${\geq}12years$, respectively. Perilla seed oil and soybean oil were main sources of n-3 FA in subjects aged ${\geq}50years$ and aged < 50 years, respectively. CONCLUSIONS: Estimation of mean fatty acid intakes of this study using nationally represented samples of the Korean population could be useful for developing and evaluating national nutritional policies.

• Nutrition Research and Practice
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• v.4 no.3
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• pp.229-234
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• 2010

Recently, we found and analyzed vitamin $B_{12}$ in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin $B_{12}$ intake and its dietary sources and the vitamin $B_{12}$ status in the very old elderly Koreans. We measured serum vitamin $B_{12}$ level and estimated the amounts of vitamin $B_{12}$ intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age of the subjects (n = 127) was 98.0 years (85-108 years). The assessment on energy and nutrient intake involved a one-day 24-hour recall, and serum vitamin $B_{12}$ concentration was measured by radioimmunoassay. Overall diet pattern was not different between the 85-99 yr-old group and centenarians, except centenarians were taking more dairy product. The average ratio of plant food to animal food consumption was 87.5:12.5 in weight. The average vitamin $B_{12}$ intake of our subjects was 3.2 ${\mu}g$, and 52.7% of subjects consumed under estimated average requirement, 2.0 ${\mu}g$/day. On dietary source, 67.3% of dietary vitamin $B_{12}$ was from meat, eggs and fishes and 30.6% was from plant foods, such as soybean-fermented foods, seaweeds, and kimchi. The average serum vitamin $B_{12}$ concentration was 450.5 pg/mL, and low serum vitamin $B_{12}$ (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin $B_{12}$ intake was significantly lower in subjects with low serum vitamin $B_{12}$ (0.79 ${\mu}g$/day) than those with normal serum vitamin $B_{12}$ (3.47 ${\mu}g$/day). There were no significant difference in vitamin $B_{12}$ intake and its dietary sources and serum vitamin $B_{12}$ level between the 85-99 yr- old group and centenarians. In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin $B_{12}$ status in very old elderly Koreans.

• Journal of Nutrition and Health
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• v.34 no.2
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• pp.213-221
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• 2001

Because the intake of vitamin A had been consistently found to be low among Koreans, there has been a concern that mild vitamin A deficiency might be prevalent in the population. However, the inaccuracy of vitamin A database has long been suspected database for the nutrient. This study was performed to assess the vitamin A and E status in 208 adults over 20 years of age living in a rural area of Korea. Newly modified database for vitamin A and E was used to estimate the dietary intake of the subjects in this study. A cross sectional survey of dietary intake with 24-hour recall method was conducted. Serum retinol and $\alpha$-tocopherol levels of the subjects were analyzed in fasting samples using HPLC. For vitamin A, mean levels of dietary intake and percent of RDA were 620.3$\pm$1087RE/day and 88.6$\pm$155.4%, respectively, which were considerably higher than the levels reported in 1995 Korean national Nutrition survey(470.1RE/day and 67.2%, respectively). For vitamin E, the levels were 9.74$\pm$6.30mg/day and 97.4$\pm$63.0%, respectively. Mean concentration of serum retinol was 83.1$\pm$30.1$\mu\textrm{g}$/dl and none of the subjects was below 10$\mu\textrm{g}$/dl, or deficient level. Mean serum retinol in men, 99.8$\pm$30.4$\mu$g/dl, was significantly higher than in women, 70.7$\pm$23.4$\mu\textrm{g}$/dl (p<0.01). Mean concentration of serum $\alpha$-tocopherol was 1.17$\pm$0.52mg/dl and that of one subject was below 0.5mg/dl, or deficient level. Serum $\alpha$-tocopherol levels of the old subjects were higher than the younger subjects in both sexes(p<0.05). These data suggest that contrary to the previous reports about low intake of vitamin a, intake and serum levels of vitamin A among the subjects are not low. Also, in this study, intake and serum levels of vitamin E are not low, either. (Korean J Nutrition 34(2) : 213~221, 2001)

• Journal of Nutrition and Health
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• v.34 no.7
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• pp.762-769
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• 2001

Recently developed TRAP assay(Total Radical-trapping Antioxidant Potential) is a new technique which enable effectively the measurement of total antioxidant status in the plasma. Researches using TRAP method have rarely been reported in Korea. Therefore, we investigated effects of various life-style and dietary factors on plasma TRAP level in Korean adult population. The subjects consisted of 161 health adult male(n=105) and female (n=56) aged 19-57. A self-administered questionnaire ascertained life-style factors including smoking habits, alcohol use, physical activity. Dietary factors were analyzed by 24 hour recall method. TRAP was determined spectrophotometrically in plasma at 734nm. Mean plasma TRAP concentrations were slightly higher in males (1.35$\pm$0.02mM) and females(1.30$\pm$0.02mM) without significance. There were significant correlations between plasma TRAP levels and life-style factors including exercise and smoking Plasma TRAP levels were affected more by exercise than by smoking. Moderate amount exerciser(exercise time $\geq$30min/day) had significantly higher level of plasma TRAP levels in male smokers(1.33$\pm$0.03mM) were significantly lower than those in male nonsmokers(1.39$\pm$0.01mM, p<0.05), but the difference was not seen in female subjects. Intakes of vitamin C(r=0.288, p=0.007) or folate (r=0.258, p=0.016) were positively correlated with plasma TRAP levels in nonsmokers, but those relations were not seen in smokers. Dietary factors such as vegetables (r=0.288, p=0.007)or folate (r=0.258, p=0.016) were positively correlated with plasma TRAP levels in nonsmokers, but those relations were not seen in smokers. Dietary factors such as vegetables (r=0.277, p=0.009) and legumes(r=0.263, p=0.013) consumption were positively related to plasma TRAP concentrations also in nonsmokers only. Regular green tea drinkers showed significantly greater level of plasma TRAP than the non green tea drinkers(1.36$\pm$0.01mM vs 1.30$\pm$0.03mM, p<0.05). These results suggest that the regular exercise($\geq$30min daily), nonsmoking, and consumption of vegetables, legumes and green tea would contribute to improving plasma TRAP levels in Korean adults.

• Journal of Nutrition and Health
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• v.50 no.6
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• pp.624-644
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• 2017

Purpose: This study analyzed iodine intake by establishing an iodine database of general Korean foods eaten by Korean adults based on the data from the 1998 ~ 2014 KNHANES (Korea National Health and Nutrition Examination Survey). Methods: Data on 56,818 subjects aged 19 years and older were obtained from health behavior interviews and a 24-hour dietary recall survey. Iodine intake of subjects was analyzed according to general characteristics, dietary lifestyle, food groups, and cooking method. Results: An iodine database was established for 312 food items. The mean iodine intake of Korean adults decreased from $641.6{\mu}g$ in 1998 to $236.2{\mu}g$ in 2014 per day. Iodine intake of women was higher than that of men. For age distribution, those aged 30 ~ 49 years constituted more than 39 ~ 46% of subjects by survey year. Regarding iodine intake according to dietary lifestyle, the highest iodine intake was 29.4 ~ 34.4% for lunch while that of breakfast decreased. The highest iodine contribution by food group was seaweed such as kelp, sea mustard, and laver. Conclusion: The results of this study indicate that iodine intake of Korean adults has been decreasing, and iodine intake is associated with the prevalence of thyroid disease. This study provides basic data for the estimation of iodine intake in Korean adults.