• 한국식품영양학회지
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• 제4권2호
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• pp.175-186
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• 1991

The purpose of this study is to provide useful information which will aid in the promotion of nutritional policy in the Korean rural area which are derived from a survey of intake and source of protein in some Korean rural adults and the correlations between their protein nutrition and various nutrients, the uses of tobacco, alcohol, coffee, etc. The survey was conducted from July, 24 through July, 18, 1989. The healthy subjects were 45 males(average age 42.3, average BMI 22.1kg/m2) and 55 females (44 years, 21.2 kg/m2) residing in Sungjoo Kyun, Chulanam-Do, Korea. The subjects were examined for the anthropometric, food Intake and food habits. Their daily diets were measured by 24-hr recall method. The results can be summarized as follows : The daily mean protein intakes of male and female subjects were 9595 of RDA(66, 5g) (16. 7% of total food intake per day) and 102.3Bh of RDA(61g) (14.8% of total intake per day) respectively. The order of sources of animal protein in all subjects was fish(47.9%), meat(29.8%), milk (12%), and egg(10.3%). Among protein sources the intake frequencies of fork and chicken were higher than those of others. The protein nutrition of the subjects showed positive correlations with energy and fat, carbohydrate, fiber at the level of significance of 1%. The protein nutrition of the male subjects showed no correlation with age, BMI, uses of alcohol, coffee, medicine, but the plant protein nutrition showed a positive correlation with smoking and exercise(at 5%). And the protein nutrition of the male subjects showed no correlations with uses of tobacco, alcohol, coffee, medicine and their opinion of their present state of their health, but the age of the male subjects showed negative correlations with milk(at 1%) and egg(at 5%). In conclusion, the daily protein Intake was good and the main sources of animal protein were fishes in rural adults. The protein nutrition of the subjects showed a correlation with energy, fat, carbohydrate and in the case of female, milk and egg intakes showed the negative correlation with age.

• 대한지역사회영양학회지
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• 제29권3호
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• pp.173-188
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• 2024

Objectives: The study aim was to analyze the regional differences in dietary protein intake and protein sources of Korean older adults and their association with metabolic syndrome. Methods: Study participants were 1,721 older adults aged 65 and over who participated in 2016-2019 Korea National Health and Nutrition Examination Survey. Using 24-hour recall dietary intake data, protein intake and their food sources were examined. The association between protein intake and metabolic syndrome, obesity, and abdominal obesity were analyzed by multiple logistic regression. Results: Total protein and animal protein intakes were higher in urban area (60.0 g, 24.4 g, respectively) than in rural area (54.6 g, 19.6 g, respectively). With increase of protein intake level, animal to total protein proportion was increased in both areas. Total protein and plant protein intake was negatively associated with the risk of obesity, abdominal obesity in both areas. Animal protein intake was negatively associated with the risk of obesity in both areas, and with abdominal obesity only in urban area. In urban area, plant protein intake was also negatively associated with the risks of metabolic syndrome, elevated triglyceride, and reduced high density lipoprotein-cholesterol. In urban area, the risk of metabolic syndrome was decreased when their protein intake was more than 0.91 g/kg and was lowest when their protein intake was more than 1.5 g/kg (P for trend < 0.001). Conclusions: Korean older adults showed inadequate protein intake and those in rural area showed lower animal protein intake than in urban area. The risk of obesity and metabolic syndrome was decreased with the increase of protein intake level. These findings may help develop effective nutrition support strategy for older adults to reduce regional health disparity.

• 한국축산식품학회지
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• 제41권5호
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• pp.855-868
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• 2021

The present study was designed to investigate the effects of protein formula with different casein (C) to whey protein (W) ratios on dispersion stability, protein quality and body composition in rats. Modification of the casein to whey protein (CW) ratio affected the extent of protein aggregation, and heated CW-2:8 showed a significantly increased larger particle (>100 ㎛) size distribution. The largest protein aggregates were formed by whey protein self-aggregation. There were no significant differences in protein aggregation when the CW ratios changed from 10:0 to 5:5. Based on the protein quality assessment (CW-10:0, CW-8:2, CW-5:5, and CW-2:8) for four weeks, CW-10:0 showed a significantly higher feed intake (p<0.05), but the high proportion of whey protein in the diet (CW-5:5 and CW-2:8) increased the feed efficiency ratio, protein efficiency ratio, and net protein ratio compared to other groups. Similarly, CW-2:8 showed greater true digestibility compared to other groups. No significant differences in fat mass and lean mass analyzed by dual-energy x-ray absorptiometry were observed. A significant difference was found in the bone mineral density between the CW-10:0 and CW-2:8 groups (p<0.05), but no difference was observed among the other groups. Based on the results, CW-5:5 improved protein quality without causing protein instability problems in the dispersion.

• Nutrition Research and Practice
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• 제11권4호
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• pp.281-289
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• 2017

BACKGROUND/OBJECTIVE: The incidence of colorectal cancer (CRC) has been attributed to higher intake of fat and protein. However, reports on the relationship between protein intake and CRC are inconsistent, possibly due to the complexity of diet composition. In this study, we addressed a question whether alteration of protein intake is independently associated with colonic inflammation and colon carcinogenesis. MATERIALS/METHODS: Balb/c mice were randomly divided into 4 experimental groups: 20% protein (control, 20P, 20% casein/kg diet), 10% protein (10P, 10% casein/kg diet), 30% protein (30P, 30% casein/kg diet), and 50% protein (50P, 50% casein/kg diet) diet groups and were subjected to azoxymethane-dextran sodium sulfate induced colon carcinogenesis. RESULTS: As the protein content of the diet increased, clinical signs of colitis including loss of body weight, rectal bleeding, change in stool consistency, and shortening of the colon were worsened. This was associated with a significant decrease in the survival rate of the mice, an increase in proinflammatory protein expression in the colon, and an increase in mucosal cell proliferation. Further, colon tumor multiplicity was dramatically increased in the 30P (318%) and 50P (438%) groups compared with the control (20P) group. CONCLUSIONS: These results suggest that a high protein diet stimulates colon tumor formation by increasing colonic inflammation and proliferation.

• Preventive Nutrition and Food Science
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• 제18권3호
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• pp.210-213
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• 2013

The aim of this study was to investigate the effects of isolated protein from white rice on lipid metabolism in a hypercholesterolemic animal model. Male Sprague-Dawley rats were divided into three groups and fed either a normal diet or a high-cholesterol diet (HCD) containing either casein or isolated rice protein for 4 weeks. Compared with rats fed a HCD with casein, the total cholesterol (TC) level in the plasma was significantly reduced in the rats fed rice protein. However, no significant differences were observed in the triglycerides, high-density lipoprotein (HDL), and glucose levels among the experimental groups. Hepatic total lipids and TC levels were significantly decreased by supplementation with rice protein. In addition, rice protein significantly increased the levels of TC and bile acids in the feces. These results suggest that rice protein may improve HCD-induced hypercholesterolemia by enhancing fecal excretion of cholesterol.

• Journal of Plant Biotechnology
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• 제8권1호
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• pp.1-8
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• 2006

The differential response of soybean cultivars with or without sulfur (S) application was observed under fold conditions. Plant biomass decreased by sulfur deficiency but the reduction was less in Bragg variety about 26 % relative to the control than other ones over 45%, probably due to less reduction in loaves and pods. The photosynthetic rate of Bragg cultivar was also unaffected by the absence of sulfur application while it depressed in other lines. Soybean cultivars were compared in terms of storage protein, protein quality and biomass production by application of sulfur nutrition. The storage protein concentration tended to decrease without sulfur application in all the cultivars, however the differential response of protein quality only by 11S/7S ratio to sulfur nutrition status was observed: For instance, Bragg cultivar had higher biomass and protein production but protein quality decreased at sulfur deficiency. On the other hand, biomass and protein production in other cultivars remained louver at sulfur deficiency but protein quality differed genetically in spite of sulfur nutrition status. These results suggest that the response of soybean to sulfur nutrition is controlled by genotypic difference and sulfur supply status.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.278-281
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• 2002

The objective of the current study was to determine the influences of dietary proteins and methionine on plasma lipid concentrations. Thirty growing male Sprague-Dawley rats were fed diets similar in all respects except that dietary protein was from either casein, soy protein isolate, or soy protein isolate supplemented with L-methionine (0.24 %). The animals were fed experimental diets ad libitum for nine weeks. Plasma total-cholesterol concentrations were unaffected by the protein source or methionine supplementation. Plasma triglyceride concentrations were lower in rats of methionine supplemented soy protein diets (76 mg/dL) than in the rats fed casein or soy diet (120 mg/dL, 109 mg/dL, respectively). These results indicate that soy protein reduces plasma triglycerides relative to casein in rats fed cholesterol free diets, and that methionine-supplemented soy diets decrease plasma triglyceride concentrations more than soy protein alone.

• Journal of Nutrition and Health
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• 제26권7호
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• pp.851-857
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• 1993

Atherosclerotic vascular disease is a major cause of the increased morbidity and mortality assciated with diabetes mellitus. The prominent role of nutrition in hypercholesteolemia and atherosclerosis is generally accepted. Diet is a key element in the management of diabetes (type I-IDDM), yet the appropriate diet for patient with diabetes mellitus is not well known. Dietary protein has been shown to have a significant effect on plasma cholesterol levels in both experimental animals and humans. The present experiment was designed to determine the effect of the dietary protein level(20% vs 60%) on plasma glucose concentration, lipids profile, insulin and glucagon levels from non-diabetic and streptozotocin-induced diabetic rats. Results showed that a high protein diet decreased triglyceride concentration in diabetic rats. Also diabetic rats fed a high protein diet were hypocholesterolemic than rats fed a control diet. There were no effects by level of protein on fasting blood glucose concentration and insulin/glucagon ratio. Results from the present study suggest that a high protein diet may be beneficial to control pasma lipids in chemically-induced diabetic rats.

• 대한지역사회영양학회지
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• 제27권1호
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• pp.47-60
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• 2022

Objectives: This study aimed to evaluate dietary protein intake and its adequacy among Korean adults during recent 10 years. Methods: Based on the 2010 ~ 2019 Korea National Health and Nutrition Examination Survey (KNHANES) data, a total of 51,296 adults aged 19 years old or more who participated in a one-day 24-hr dietary recall were included. Dietary protein intake was estimated as percentages of total energy (% of energy) and grams per body weight (g/kg/day) and compared with the 2020 Dietary Reference Intakes for Koreans to evaluate the adequacy of protein intake. In addition, proportions of people whose protein intakes were less than the estimated average requirement (EAR) and above the upper limit of the acceptable macronutrient distribution range (AMDR) (> 20% of energy) were calculated according to sociodemographic characteristics. Results: Protein intake was increased from 14.7% of energy in 2010 to 15.6% of energy in 2019 among Korean adults. However, there was no increase in protein intake relative to the recommended nutrient intake (% RNI) during the recent 10 years. Protein intake relative to the RNI was decreased from 130.2% in 2010 to 121.1% in 2019 (P for trend < 0.0001) among total participants, and a significant decreasing trend was observed in all age groups except for over 65 years old. However, protein intake relative to the RNI was lowest in the elderly (98.6%). Proportions of low protein intake (< EAR) and high protein intake (> AMDR) increased in the past 10 years (P for trend < 0.0001 for all), and these were associated with socioeconomic statuses, such as education and household income levels. Conclusions: These findings suggest that protein adequacy in Korean adults has not been improved over the past decade compared with recommended levels. Nutritional education and intervention programs should consider different intake levels according to sociodemographic characteristics.

• Journal of Nutrition and Health
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• 제57권2호
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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.