• Journal of Nutrition and Health
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• v.57 no.2
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• pp.261-274
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• 2024

Purpose: Recently, high-protein diets have become highly popular, and the market for protein products has steadily increased in Korea together with the development of various types of such products. However, there is limited information on the consumption of protein supplements (PS) or protein-fortified foods (PF). Thus, this study aimed to evaluate the use of PS/PF among young adults in Jeju. Methods: A total of 350 adults (140 men and 210 women) aged 19-39 years voluntarily participated in this study from June 2022 to May 2023. PS/PF use was measured using a questionnaire. Dietary intake was assessed using a 24-hour dietary recall. Results: Approximately 31.4% of the participants (n = 110) had consumed PS/PF for more than 2 weeks during the past year and 71.8% of them (n = 79) were still consuming these products (PS/PF consumers). The PS/PF consumers tended to be male and physically active (p < 0.05 for all). The most frequent reason for PS/PF use was muscle gain (59.5%), followed by protein supplementation (19.0%) and body fat loss (13.9%), and the most frequent type of PS/PF consumed was powders (70.6%), followed by drinks (17.7%) and bars (8.8%). The PS/PF consumers tended to consume a high-protein low-carbohydrate diet compared to the non-consumers. The prevalence of consuming dietary protein less than the estimated average requirement (EAR) was significantly lower in PS/PF consumers (13.9%) compared to non-consumers (25.4%; p = 0.0316). Conclusion: These findings indicate that the necessity of protein supplementation should be determined based on the current dietary protein intake and individual requirements. The study also provides the basic information for establishing guidelines for appropriate protein intake.

• Journal of the Korean Society of Food Culture
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• v.10 no.5
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• pp.405-417
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• 1995

This research was designed to see the relationship among nutrient intake, food intake frequency and psychosocial stress in ordinary life. The subjects were 190 males and 263 females of university students in urban areas. There were significant correlations between nutrient intake and stress value, and between food intake frequency and stress value. In male, the more they consumed energy, protein and carbohydrate, the higher they had stress in several categories. But in female the results were reversed. Their stress values were lower when they have consumed protein source food frequently. And in general, stress values of female were higher than those of male. From these results, we conclude that nutrient intake tends to be decresed with increase stress in less stressful condition, but to be increased in more stressful condition.

• Korean Journal of Community Nutrition
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• v.9 no.1
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• pp.38-46
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• 2004

Few studies have conducted the bone health benefits of usual dietary isoflavone intake in Korean college-student women. To elucidate this benefitial effects and correlations between dietary isoflavone and nutrients intake and bone formation marker (ALPase, osteocalcin), questionnaires, anthropometric measurements, serum mineral (Ca, P, Mg) concentrations were analyzed. Fifty three subjects were used in this study. The average age, height, body weight, BMI, body fat content and triceps skinfold thickness were 21.43 year, 161.07 cm, 52.81 kg, 20.48 kg/$m^2$, 20.72% and 17.59 mm respectively. Soy food intake frequencies were soybean > soybean curd > soypaste stew > soybean milk. The average calorie, protein and Ca intake were 1766.21 $\pm62.54 kcal\;66.45\pm2.00 g\;and\; 549.62 \pm 27.55 mg$ respectively. Serum ALPase activity and osteocalcin concentration were 115.74$\pm3.6u/L$ and 7.15 ng/$m\\ell$ respectively. Usual dietary isoflavone intake was positively related to calory, protein, Ca, P intake and serum Ca, Mg concentration. Serum osteocalcin concentration was negatively correlated with isoflavone intake ($r^2$=0.28, p < 0.05). In these results, usual dietary isoflavone can support an additive effect to bone health and Ca nutrition.

• Nutritional Sciences
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• v.3 no.2
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• pp.83-88
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• 2000

The association between nutrient intake and nutritional status was investigated with anthropometric measurements, body composition and blood biochemical indices in 56 healthy young men fed balanced diet for two years. Compared with Korean recommended dietary allowances (Korean RDA), all nutrient intakes were adequate. Height and body weight were significantly (p < .01 - p < .05) positively correlated to the intakes of energy, protein, sodium, potassium vitamin A and vitamin $B_1$. The lean weight was significantly (p < .001 - p < .05) correlated to the intake of energy, protein, sodium, potassium, vitamin A, vitamin B$_1$. niacin and vitamin C. The skinfold thickness of triceps and suprailiac was significantly (p < .01 - p < .05) correlated to the intake of energy, sodium, potassium, but that of thigh was not correlated. The significant correlations neither between nutrient intake and blood biochemical indices nor between nutrient intake and blood pressure were shown. These results suggest that nutritional status as anthropometric indices and body composition is associated with nutrient intake in young healthy adults on balanced diet, however, the nutritional status as blood biochemical indices of active people is neither endangered nor improved in comparison with less active ones.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.125-133
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• 2000

The purpose of this study was to investigate eating behavior, nutritional status and health condition of obese adult attending a weight control exercise. The subjects of this study consisted of 81 adult in some areas of Daegu. Their weight, height, triceps, midarm circumference were measured and their dietary intake and eating behavior were obtained by using questionnaires. Anthropometry was conducted to determine obesity. Average age of men and women were 38.1 and 35.2 years old respectively. Their intake of energy and protein were 69.5% and 97.4% of RDA respectively. Energy intake of normal and obese group was 74.4% and 64.9% of RDA respectively. Protein intake of normal and obese group was 99.7% and 95.3% of RDA respectively There was a negative correlation between PIBW and energy intake, PIBW and carbohydrate intake, BMI and energy intake, and BMI and carbohydrate intake. A relative magnitude of factors affecting weight decrease rate was analyzed by Stepwise multiple regression analysis. Overall results about relative influence of independent variables to dependent variable(weight decrease rate) indicated that the BMI(p<0.01) was the most significantly correlated with weight decrease rate in all subjects. The results of this study suggest that the extensive nutrition education in weight control program should be emphasized to prevent obesity early.

• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.143-157
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• 1993

This research aims to find the information concerning nutritional status and food intake in Korean dirt betic men. Thus, the survey was made on 202 NIDDM patients over 35 age at University Hospital. The data were analysed using F-test and mutiple comparison in SAS package program. Main results were as follows : Incidence of diabetes is high in their forties and fifties. Most of them are salary men, administrators, and professionals in middle class, who reside in metropolitan area including Seoul. They used to take light exercise and were founded NIDDM by subjective symptoms. 36.6% of them have other diseases simultaneously such as hypertension, cancer, etc. Food intake pattern prior to incidence was that intake frequency of grains, sugars, protein foods, and liking foods was higher than of processed foods. Amounts of calorie intake were shown to be lower than normal persons, so that it seemed to be controlled by doctors. In addition, the calorie ratio derived from fat was lower than RDA. Thus protein and carbohydrate ratio was relatively higher than RDA. Total moan fatty acid intake was 32.15g and it is no significance among weight groups in various fatty acid intakes. With respect to the physical standards of the diabetic men, weight, PIBW BMI, BMM, 757, arm circumference, and waist /hip ratio were higher than in normal. Therefore it seemed that these factors would be related to the diabetics. From now on, it is required to research the correlations of fatty acid intakes on the diabetes and their influence to serum lipid profiles.

• Journal of Nutrition and Health
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• v.9 no.3
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• pp.8-17
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• 1976

This study was carried out to estimate the minimum protein requirement for the Korean college girls, and to see the effect of carbohydrate intake on the minimum protein requirement in the rat. In the first experiment, three students attending Ewha Womans University were given protein free diet for 7 days while caloric intake were adjusted to maintain constant body weight. Endogenous nitrogen excretion was measured to estimate their minimum protein requirement. Second experiment was carried out in 3 parts to find out the effect of carbohydrate intake on the minimum protein requirement using 15 female, 50 days old rats weighing 120g. Inexperiment 2-1, the rats were fed protein free diet for 9 days and endogenous nitrogen excretion was measured to determine the minimum protein requirement of the rats. In experiment 2-2, the minimum casein requirement of the rats needed to maintain nitrogen equilibrium was estimated by the least squares regression method feeding 3 different levels of casein determined from the result of experiment 2-1. Finally, in experiment 2-3, the rats were given the minimum casein requirement for 7 days with 3 different levels of carbohydrate to find out the effect of carbohydrate intake on the nitrogen balance. The results of this study were as follows. Experiment I. Daily endogenous nitrogen losses of 3 college girls were 1.89g in urine, 1.10g in feces and 0.0108g from skin since the total daily endogenous nitrogen loss was 3.0g and the total daily nitrogen intake was 0.52g, the minimum nitrogen requirement of these subjects was about 2.48g/day (15.5g protein/day). Experiment II. Experiment 2-1: daily endogenous nitrogen losses of the rats fed protein free diet were $22.63{\pm}0.48\;mg$ through urine and $13.12{\pm}0.47\;mg$ in feces. The total daily endogenous nitrogen ouput was $35.71{\pm}1.27\;mg$ and the minimum protein requirement of the rats was 225mg/day in this study. Experiment 2-2: the minimum casein requirement needed to maintain the rats in nitrogen equilibrium was determined to be 340mg/day. Experiment 2-3: the rats were given 350mg/day casein with 3 different levels of carbohydrate (12,26 or 46 Cal by sugar-cornstarch mixture). The nitrogen balances were measured to be +0.0021, +0.0073 and +0.0143 respectively and there were significant differences among 3 groups.

• Journal of Nutrition and Health
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• v.18 no.1
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• pp.5-13
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• 1985

The purpose of this study was to provide the proper nutritional management, and help to improve the health of girl students in a rural area. The nutritional survey, and blood sampling was conducted for five days, from April 26 to 30, 1983. The subjects of this survey were 110 students of girl's high school in Cheongyang area. The results were summerized as follows; 1) The daily food intake was 842.3g and that of animal foods was 34.4g. The average intake of calorie, protein, Ca, Fe, thiamin, riboflavin and niacin except Vit. A and Vit. C was below the RDA. Total calorie intake was l,802kcal. The ratio of carbohydrate, protein and fat was 81:11:8. 2) The extent of malnutrition was explained in terms of the amount of calorie, protein, Ca, Fe, and Vit. C. The predicted percentage of deficiency was 47.3% in calorie, 46.4% in protein, 61.8% in Ca, 48.2% in Fe, and 15.5% in Vit C of total subjects. 3) The mean values of Hgb, Hct and MCHC were 13.15g/dl, 39.57% and 33.2%, thus, the anemic prevalences were 10.9%, 2% and 78.2% respectively. The mean values of SI.TIBCand TS were $109.86{\mu}g$/61, $317.11{\mu}g/dl$ and 34.59%. 4) The correlation between the economic levels and nutrients intake was significant. Correlation between weight and nutrients intake was also significant but nutrients intake was not significantly correlated to blood contents.

• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.95-102
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• 2007

To elucidate the relationship among body mass index, nutrient intake and blood antioxidant capacity in the postmenopausal period, 60 women residing in Iksan area were recruited. Body mass index (BMI) was calculated base on height and weight, and food and nutrient intakes were estimated by 24-hour recalls of 3 non-consecutive days. Parameters of antioxidant capacity including the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (TA) were measured in fasting blood samples from the subjects. The average age, height, weight and BMI of the subjects were 65 years, 151.1cm, 59.5 kg and 26.0 m/kg$^2$, respectively. The macronutrient intake rate of carbohydrate : protein : fat were 65:17.5:17.5; the mean intakes of energy and protein were 1532.7 kcal (86.3% of RDA) and 67.1 g (122.0% of RDA) respectively. The mean intakes of phosphorus, vitamin A, niacin and vitamin C were higher than Recommended Daily Allowance (RDA) for Koreans. On the other hand, calcium and riboflavin intakes were only 84.6% and 70.4% of RDA. Among the parameters of antioxidant capacity, SOD activity was significantly lower in lean subjects (BMI<20) than in the normal or overweight subjects (BMI${\geq}$20) (p<0.05). TAs of the subjects with the highest intakes of vegetables and fruits were significantly higher than those of subjects with lower intakes (p<0.05). Antioxidant capacity was compared among subjects according to 3 different nutrient intake levels according percentage of RDA for Koreans for selected nutrients with the following results: The high protein and niacin groups exhibited significantly lower TA status than those of the other intake groups (p<0.05). In conclusion, the low BMI was associated with lower SOD activity in postmenopausal women. Higher consumption of fruits and vegetables was associated with higher TA. When protein and niacin intakes were excessive, SOD activity and TA tended to be low. SOD and TA, among antioxidant indexes, seemed to be mostly influenced by other factors. Therefore, more studies on the effects of nutritional intake and the activity of antioxidant enzyme should be conducted.

• Journal of the Korean Dietetic Association
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• v.14 no.4
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• pp.371-381
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• 2008

In order to elucidate the effects of a lacto-ovo vegetarian diet on serum lipid levels, 91 male collegians residing in the Seoul area were recruited. The vegetarians did not smoke tobacco nor drink alcohol. Their anthropometric measurements, dietary intakes, and blood lipid concentrations were compared to age-matched omnivorous controls. The subjects were divided into four groups. The four groups were: 1) NSNDV (n=25): Non Smoking Non Drinking Vegetarians, 2) NSNDO (n=10): Non Smoking Non Drinking Omnivores, 3) SDO (n=37): Smoking, Drinking Omnivores, 4) SDM (n=11): Smoking Drinking Meat-eaters. Total serum cholesterol, HDL-cholesterol and hematocrit were analyzed. The results were as follows: Weight (p<0.05) and BMI (p<0.01) were significantly higher in SDM than NSNDV. Dietary protein (p<0.01), iron (p<0.05) and dietary lipids (p<0.01) from animals in NSNDV were significantly lower than the results in the SDM. Interestingly enough, we noted no significant differences between the four groups in terms of average total dietary protein, dietary lipids and dietary iron, total serum cholesterol, or HDL-cholesterol. Dietary fiber intake was significantly higher in NSNDV than in SDM (p<0.05). Weight, BMI, and total cholesterol were significantly positively correlated with animal protein (p<0.05) and animal lipid (p<0.01) intake. These results showed that vegetarian collegians who haven't smoked tobacco nor drunk alcohol evidenced lower body weight, BMI, and dietary animal lipid intake, but higher dietary fiber intake, than the other three groups. Additionally, intake of animal protein (p<0.001) and intake of animal lipids (p<0.001) were significantly positively correlated with body weight, BMI, and total serum cholesterol in male collegians.