• Journal of Preventive Medicine and Public Health
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• v.40 no.3
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• pp.239-248
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• 2007

Objectives : This study was conducted to investigate the systematic error, such as seasonal change or inadequate food items, in a food frequency questionnaire administered to workers in a Nuclear Power Plant, Korea. Methods : We performed three repeat-tests with 28 subjects on May 13, July 8 and Dec 16, 1992. Our food frequency questionnaire (FFQ) comprised 84 foods organized into 7 food-groups, and was composed of the items of usual intake frequency (8 categories) and the amount per intake (3 or 4 categories) over the previous year. We compared the means of intake frequency and the frequency of the portion-size according to each season using Repeated Measures ANOVA and Pearson's chisquare test with Fisher's exact test. Results : We found the significant seasonal changes of several food items in intake frequency measurement. These items were typical seasonal foods such as mandarin orange, plum and green vegetables, while the single questions consisted of inadequate food items such as thick beef or similar soup and various kimchi products. Significant seasonal changes in portion-size were found in only two items: cooked rice-brown and fresh frozen fishes. Conclusions : The systematic errors observed could caused loss of validity in the FFQ. Consideration should be given for seasonal variation in FFQ survey and methodological concerns are needed to improve the quality for measuring usual diet pattern.

• Korean Journal of Community Nutrition
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• v.2 no.4
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• pp.578-592
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• 1997

The use of semiquantitative food frequency questionnaires to estimate dietary intake has become widespread in nutritional epidemiologic studies. It had been suggested that knowledge about a person's usual portion size of each meal in addition to consumption frequency will improve the accuracy of this method. This study was performed to investigate the dietary intake status(nutrient, food, and dish intake) and one portion size of commonly consumed food and dishes to develop a semiquantitative food frequency questionnaire that will be used to expore the relationship between the incidence of cardiovascular disease and diet in Korean women after menopause. Intake of food or dish in 123 elderly women were measured by 3-day food records in March to May, 1996. The results obtained in this study were summarized as follow : 1) Calcium, vitamin A, and vitamin E intakes were less adequate than Recommended dietary allowances(RDA). 2) The subjects who consumed more than 20% of the energy from fat were 35% and the subjects consumed dietary cholesterol more than 300mg were 18$\%$. 3) The most frequently consumed foods or dishes by the subjects were Korean cabbage kimchi〉cooked rice, well-milled〉laver〉apple〉strawberry〉mixed rice〉soybean soup. 4) The major dish groups which contributed to most daily nutrient intakes were cooked rice, Korean cabbage kimchi, soybean soup because of large amount and high frequency of intake although they do not contain large amount of most nutrients. 5) One portion size of commomly consumed foods and dishes in elderly women was different from one portion size suggested in the Korean nutrition society. This study provides information for the design of data-based semiquantitative food frequency questionnaire. for Korean elderly women. In addition, they may be useful to health care planners or nutrition educators. (Korean J Community Nutrition 2(4) : 578-592, 1997)

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.314-324
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• 2000

Evaluation of nutritional status of the elderly imposes different problem from the other age groups. It is essential to use right instrument to assess food consumption. In Korea, the food frequency questionnaire has not been applied widely to elderly people. The purpose of this study is to assess the possibility of employing a semi-quantitative food frequency questionnaire(FFQ) for the Korean elderly to estimate nutrient and/or food intakes. In this study the FFQ for the elderly was developed and validated. The subjects were 144 free-living old women aged from 65 to 90. The FFQ was designed with 4 items for cereals and 86 items for other foods and with frequency of 12 intervals. Three portion sizes were given to select : 1/2 of standard amount, standard amount, and 11/2 of standard amount. ach subject was interviewed with newly developed FFQ form and same subjects were also involved to complete 3-day diet record. Nutrient intake was calculated using software program developed by our group. The nutrient intakes by the FFQ was validated by comparing the results with 3-day diet record. The FFQ estimated significantly higher mean intakes of energy, carbohydrate, protein, fats and vitamin C than did the diet reconrds(p<0.05). Pearson's correlation coefficients between two methods ranged from 0.21 for vitamin Q to 0.69 for alcohol(mean r=0.53). From 32% to 42% of the subjects were classified in the same quintile of nutrient intake by two methods, and 63% to 84% were classified in the same or adjacent quintile. On average, only 4% of the subjects were misclassified into extreme quitiles. The results indicate that the FFQ developed for the elderly in this study is useful for classifying individuals by rank and identifying groups at extremes of nutrient intakes.

• Nutritional Sciences
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• v.4 no.2
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• pp.98-103
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• 2001

The aim of this study was to determine the association between, smoking, exercise, sex, and dietary carotenoids ($\alpha$-carotene, $\beta$-carotene, $\beta$-cryptoxanthin, lutein + zeaxanthin, lycopne) intake in Korean middle-aged adults. Food-frequency questionnaire were analyzed from 304 healthy adults (115 men, 189 women) aged 20 - 59. The self-administered questionnaire contained subject s habitual diet and alcohol intake were the previous 3 months. Data on frequency of 102 foods, including vegetables, fruits, beverages and legumes were analyzed. Total dietary carotenoids intake were 27.13 $\pm$ 3.09 mg/d for men and 26.71$\pm$ 2.82 mg/d for women. It was found that smoking had no significant contribution to the dietary intake of carotenoids. Among other lifestyle factors that had significant correlation was the amount of exercise time. The increases in exercise time was associated with increase in carotenoids intake (r= 0.121, p : 0.04). The major contributors of $\alpha$-carotene and $\beta$-carotene were carrots consumed as single-food item or carrot juice. Lutein and Zeaxanthin intake mainly came from spinach and most lycopene intake was derived from tomato products not fresh tomatoes. Persimmon was the major contributor of $\beta$-cryptoxanthin. These findings provide valuable information on understanding the unique pattern of dietary intake of Korean, which might help identify the risks for developing various diseases.

• Nutrition Research and Practice
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• v.6 no.5
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• pp.444-450
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• 2012

This study was performed to evaluate the validity of the food frequency questionnaire (FFQ), which is being used at the Samsung Medical Center. In total, 305 (190 males and 115 females) participants consented and completed the 3-day diet records and FFQ. Age, gender and energy-adjusted and de-attenuated correlations ranged from 0.317 (polyunsaturated fatty acid) to 0.748 (carbohydrate) with a median value of 0.550. The weighted kappa value ranged from 0.18 (vitamin A) to 0.57 (carbohydrate) with a median value of 0.36. More than 75% of the subjects were classified into the same or adjacent quartiles. The FFQ had reasonably good validity compared with that of another study. Therefore, our FFQ is considered a proper method to assess nutrient intake in healthy Korean adults.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1183-1191
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• 1998

In order to evaluate the repeatability of nutrient values estimated from a semiquantitative food frequency questionnaire(SFFQ) for elderly Korean, a sample of 100 participants(45 men, 55 women) were interviewed to complete a SFFQ developed by this study twice at an approximately 3 month interval. The mean age of subjects was 70.4 years. Males(mein=8.75 years) had more education thu females(1.4 years). In males, Nutrient values calculated from the repeat questionnaire were not significantly different from the baseline results by paired t test. Correlation coefficients of most nutrients ranged from 0.4-0.6. For most nutrients,60-73% males classified into the lowest tertile in baseline data belonged to the same tertile in a repeat questionnaire, but these values appeared to be less than 50% for females. These results were comparable to previously published results and confirm that repeatability of nutrient intakes estimated using SFFQs was acceptable. The repeatability of SFFQ was higher for males than females, which implies that years of schooling should be considered in the development of SFFQ for the elderly. Only f3r males, Mean Adequacy Ratio(MAR) of nutrient intake was higher for those who were less nutritionally at risk and less depressed, and physically functioned better. Considering the educational level of the Korean elderly overall, more studies on the development of simpler dietary assessment methods f3r this population are needed.(Korean J Nutrition 31(7) : 1183-1191, 1998)

• Journal of Nutrition and Health
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• v.44 no.2
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• pp.171-180
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• 2011

Assessing human exposure to food-borne hazards requires standardized assessment tools. The objective of this study was to validate a newly developed dietary assessment questionnaire to assess human exposure to food-borne hazards, which include dietary behavior and food consumption patterns such as eating frequency, types of food containers and cooking methods. A total of 216 adults were recruited for two questionnaire surveys (questionnaire 1 and 2) about 1 week apart with a 3 day diet record. Reproducibility was evaluated by comparing responses from questionnaires 1 and 2, and validity was checked by comparing responses from questionnaire 2 and the 3 day diet record. Comparisons were based on the percent agreement and Spearman's rank correlation coefficient. The mean exact agreement of food containers at purchase between questionnaires 1 and 2 was 73.5%, for storing containers it was 71.9%, and for cooking methods it was 83.0%. The mean correlation coefficient for food intake frequency between questionnaires 1 and 2 was 0.71 (range, 0.50-0.83). The mean correlation coefficient of the food intake frequency between questionnaire 2 and the 3 day diet record was 0.21 (range, 0.04-0.48). The exact and adjacent agreement of food intake frequency quartile assessed by questionnaire 2 and the 3 day diet record was 65.4% (range, 51.0-82.1%). Although the correlation coefficient for food intake frequency between questionnaire 2 and the 3 day diet record was low, the exact and adjacent food intake frequency agreement was higher than 50% and reproducibility of the dietary behaviors exceeded 70%. Therefore, the questionnaire developed in this study could be applied to assess diets for the human exposure to food-borne hazards as a qualitative assessment in a large population.

• Journal of Nutrition and Health
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• v.43 no.1
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• pp.79-85
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• 2010

This study assesses the sodium intake of adults by 24-hour urine analysis, dietary records review and a food intake questionnaire. Subjects were 236 adult female in Daegu. The results are summarized as follows: Sodium intake as indicated by the 24-hour urine analysis was $5,805.4\;{\pm}\;3836.8\;mg$. This was significantly higher than intake indicated by dietary records ($4415.4\;{\pm}\;1935.1\;mg$) and the dish frequency questionnaire (DFQ 55) ($4293.5\;{\pm}\;1526.5\;mg$). The results of the 24-hour urine analysis and DFQ 55 showed that sodium intake was higher for the 65-to-74-year-old age group than for other age groups (p < 0.05, p < 0.05). Review of dietary records to examine typical sodium intake by food groups showed that 53.7% of the sodium consumed by subjects in all age groups came from seasonings and spices ($2399.0\;{\pm}\;1526.5\;mg$). The analysis of sodium intake by food groups using DFQ 55 showed 34.2% of their sodium came from consumption of kimchi (p < 0.001) and kimch, soup, stew and fish jorim accounted for 57.8% of total sodium intake. The results indicate positive correlation between age and sodium intake, as shown by the 24-hour urine analysis and food intake questionnaire (p < 0.05). Therefore, these results would be valuable as basic data for planning nutrition education for sodium intake reduction.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.1021-1027
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• 1996

This study examined the patterns of nutrient intakes measured by 1-, 3-, 7-day recalls and records as well as food frequency questionnaire among 59 females volunteers enrolled in the university in Seoul, Korea. Over a 4 month period, a modified Willett food frequency questionnaire was administered once, and a 24-hour dietary recall was conducted 12 times and a weighted dietary record 14 times. From these 12 recalls and 14 records, 1-, 3-, 7-day data were randomly selected. For energy and 11 nutrients, group mean intakes derived from food frequency questionnaire were higher than from recalls and records. Group mean intakes from recalls and records showed little differences depending on days of dietary studies and dietary methods. Measures of agreement were calculated by weighted kappa and intraclass correlation coefficient values calculated for quintile categories while comparing to the results of 26 days recalls and records. Weighted kappa values ranged from 0.11 for riboflavin to 0.36 for vitamin C for and 1-day recall, and from 0.21 for iron to 0.31 for energy for the 1-day record. Weighted kappa values were increased as the number of days of dietary studies increased (0.34-0.57 for the 3-day recalls, 0.27-0.50 for the 3-day records, 0.50-0.68 for the 7-day recalls, and 0.50-0.65 for the 7-day records). Weighted kappa values for food frequency questionnaire were higher than the 1-day data, but lower than the 3-and-7day data(0.34 for energy, 0.31 for iron and 0.22 for vitamin C). Intraclass correlation coefficients ranged from 0.21 for vitamin A to 0.57 for calcium. The degrees of agreement by different methods and days of dietary study are lower in our study compared to agreement by different methods and days of dietary study are lower in our study compared to those in previously published studies for Western populations, partly due to the differences of data analysis methods as well as of dietary patterns between those samples and ours.

• Korean Journal of Community Nutrition
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• v.7 no.4
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• pp.548-558
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• 2002

The purpose of this study was to develop a computer software program for nutritional assessment using a Semi-Quantitative Food Frequency Questionnaire (SQFFQs) and the 24-hour Recall Method. The software for the SQFFQ was divided into input, output, and database. For dietary analyses, recipe and food databases were used. The recipe database included 25 items and the food database was divided into 18 food groups. The food database was composed of 19 general nutrient items, 33 fatty acids, and 18 amino acids. The software developed in this study can be summarized as follows: 1) input items related to the individual s ages information, lifestyle, biological values, and dietary habits; 2) individualized data in percent of the Korean RDA, the energy ratios of carbohydrates, proteins and fats, the ratio of animal to plant source intakes, and the distribution of food group intakes; 3) Statistical data on the individual's information, lifestyle, biological values, and dietary intakes including the frequency of intake of cooked foods, the amounts of food, and the number of food groups, and nutrients. In the 24-hour Recall Method, the input and output consisted of the individual s information and cooked dish intakes. The individual s report included the amounts of nutrient intake according to number of meal and days, in comparison to the Korean RDA, the energy ratio for carbohydrates, proteins and fats, the ratio of animal to plant source intakes, and the distribution of food group intakes. The statistical report presented the number of food groups and foods, and the nutrient intakes. To evaluate the validity of the SQFFQ, the Spearman Rank Order Correlation and kappa values were used. As a result, correlation coefficients comparing the 24-hour Recall Method appeared to be more than 0.5, except for vitamin $B_1, B_2$, niacin, and vitamin E. The kappa values for energy and carbohydrate intakes were both 0.7, and protein, fat, vitamin C, folate, Ca, and iron intakes ranged from 0.3 to 0.7.