Dietary protein is a crucial macronutrient for systemic homeostasis, and the global interest in protein supplements has surged because of their roles in muscle synthesis, immune function, and sarcopenia prevention. In South Korea, the proportion of energy derived from protein has increased steadily over the past decade, reflecting a significant shift in dietary patterns toward greater reliance on protein. Concurrently, a wide range of protein- and amino acidbased processed foods and dietary supplements has been developed and actively consumed.Nevertheless, comprehensive data on the prevalence of protein supplement users, their characteristics across different life stages, and the contribution of supplements to total daily protein requirements are lacking. Unlike other macronutrients, the human body lacks a dedicated reservoir for protein storage, necessitating a continuous dietary supply to support protein turnover, particularly for older adults facing anabolic resistance and individuals with high physical demands. Although clinical evidence highlights that protein supplementation, particularly when combined with resistance exercise, effectively improves muscle mass and physical performance, the magnitude of these benefits remains inconsistent across different life stages and protein sources. Conversely, emerging concerns about the potential metabolic risks from chronic overconsumption suggest that the validity and safety of protein supplementation are unclear, highlighting the need for a precision nutrition approach. Thus, this review evaluates the status of protein supplement intake among Koreans, synthesizes evidence on its physiological benefits and drawbacks and examines international trends and regulatory frameworks. Developed as part of the technical assessment for the 2025 revision of the Dietary Reference Intakes for Koreans, this review addresses the current lack of longterm safety data on chronic protein overconsumption. It provides a foundational framework for evidence-based dietary guidelines and serves as a critical scientific basis for establishing future tolerable upper intake levels and nutrition policies for protein supplement use in Korea.

Purpose: This study evaluated the nutrition and food intake status among adults in Jeju, Republic of Korea, based on their sociodemographic characteristics and obesity. Methods: Nine hundred and forty-nine adults aged 19 years or older were included based on the 2022 Jeju Nutrition and Physical Activity Survey data. A dietary assessment was conducted using a one-day, 24-hour recall method, and the nutrition status was evaluated using the 2020 Dietary Reference Intakes for Koreans. The sociodemographic status included sex, age, education, and household income, and obesity was defined as a body mass index (BMI) of ≥ 25 kg/m 2 . Results: The mean age of the subjects was 49.8 years, and the overall prevalence of obesity was 48.4% (59.5% for males and 37.2% for females). The top three insufficient nutrients consumed at less than the estimated average requirement were calcium (77.7%), vitamin A (77.3%), and vitamin C (61.3%), while 40.9% of the subjects consumed fat as more than 30% of their total energy intake. The sodium intake was approximately 1.5 times higher than the chronic disease risk reduction intake level. In terms of food groups, the participants consumed more meat (148.2 g/day), seafood (69.0 g/day), potatoes, and starches (41.6 g/day) but consumed fewer vegetables (214.3 g/day) and less dairy (62.0 g/day) than Korean adults. The nutritional status and food intake patterns differed by the sociodemographic status. In addition, the obese group consumed more poultry and beverages than the non-obese group (p < 0.05 for all). Conclusion Adults in Jeju under-consume essential nutrients while over-consuming certain nutrients, such as fat and sodium. The nutritional status also varied according to the sociodemographic characteristics. These findings suggest that sociodemographic factors should be considered carefully when developing nutritional policies and programs to improve the nutritional status and address obesity among adults in Jeju.

Purpose: This study evaluated the nutrition and food intake status among adults in Jeju, Republic of Korea, based on their sociodemographic characteristics and obesity. Methods: Nine hundred and forty-nine adults aged 19 years or older were included based on the 2022 Jeju Nutrition and Physical Activity Survey data. A dietary assessment was conducted using a one-day, 24-hour recall method, and the nutrition status was evaluated using the 2020 Dietary Reference Intakes for Koreans. The sociodemographic status included sex, age, education, and household income, and obesity was defined as a body mass index (BMI) of ≥ 25 kg/m 2 . Results: The mean age of the subjects was 49.8 years, and the overall prevalence of obesity was 48.4% (59.5% for males and 37.2% for females). The top three insufficient nutrients consumed at less than the estimated average requirement were calcium (77.7%), vitamin A (77.3%), and vitamin C (61.3%), while 40.9% of the subjects consumed fat as more than 30% of their total energy intake. The sodium intake was approximately 1.5 times higher than the chronic disease risk reduction intake level. In terms of food groups, the participants consumed more meat (148.2 g/day), seafood (69.0 g/day), potatoes, and starches (41.6 g/day) but consumed fewer vegetables (214.3 g/day) and less dairy (62.0 g/day) than Korean adults. The nutritional status and food intake patterns differed by the sociodemographic status. In addition, the obese group consumed more poultry and beverages than the non-obese group (p < 0.05 for all). Conclusion Adults in Jeju under-consume essential nutrients while over-consuming certain nutrients, such as fat and sodium. The nutritional status also varied according to the sociodemographic characteristics. These findings suggest that sociodemographic factors should be considered carefully when developing nutritional policies and programs to improve the nutritional status and address obesity among adults in Jeju.

BACKGROUND/OBJECTIVES: The diet is an important route of exposure to endocrinedisrupting chemicals (EDCs). However, few studies have investigated the association between dietary intake and EDC exposure levels among Koreans. In an earlier study, we showed that the bioactivity of serum aryl hydrocarbon receptor ligands (AhRLs) could be a surrogate biomarker to indicate exposure to EDCs and that they inhibit mitochondrial function. We also found that the mitochondria-inhibiting substances (MIS) in serum ascertained by intracellular adenosine triphosphate (MIS-ATP) and reactive oxygen species (MIS-ROS) levels could be biomarkers of exposure to EDCs, as they showed a strong correlation with AhRL and the levels of EDCs in the blood. Here, we investigated the association between the consumption of specific foods and surrogate serum biomarkers for EDCs, namely AhRL, MIS-ATP, and MIS-ROS, among middle-aged Korean adults. SUBJECTS/METHODS: A total of 1,466 participants aged 45–76 yrs from the Ansung cohort of the Korean Genome and Epidemiology Study were included. Food consumption, including that of meat, fish, vegetables, and fruits, was measured using a semiquantitative food frequency questionnaire. RESULTS: Fish intake was positively associated with AhRL (β = 0.0035, P = 0.0166), whereas cruciferous vegetable intake was negatively associated with AhRL (β = −0.0007, P = 0.0488).Cruciferous vegetable intake was positively associated with the MIS-ATP levels (β = 0.0051, P = 0.0420). A higher intake of fish was significantly associated with an increased risk of high AhRL (tertile: odds ratio [OR], 1.49; 95% confidence intervals (CIs), 1.08–2.06; P for trend = 0.0305). In addition, the second-highest tertile of cruciferous vegetable intake had lower odds of high AhRL than the lowest tertile (OR, 0.73; 95% CIs, 0.54–0.97), although no significant linear trend was observed. CONCLUSION Consumption of different types of foods may be differentially associated with EDC exposure in middle-aged Korean adults.

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.

Purpose: The use of food delivery services is increasing continuously in Korea, which may lead to nutritional problems and obesity. Despite this, the research on the association between delivered food consumption and obesity has been insufficient. This study examined the relationship between delivered food consumption and dietary behaviors and obesity among young adults in Jeju. Methods: An online survey was conducted from March 15 to April 5, 2023; 312 participants aged 19–39 years were included in the final analysis. The frequency, types, and time of delivered food consumption were measured using a questionnaire. The dietary behaviors included the following: eating out, breakfast consumption, recognition of nutrition labels, and eating salty foods, vegetables, and fruit. Obesity was defined using the body mass index based on self-reported body weight and height. Results: Approximately 59.3% of the participants ordered delivery foods more than one time/ week. The frequency of delivered food consumption was higher in people who consumed breakfast < 5 times/week than those who consumed ≥ 5 times/week (p = 0.0088). People who usually eat salty foods tended to consume delivered food more frequently than those who did not (p = 0.0377). On the other hand, people who consumed fruits ≥ 1 time/day had a higher frequency of delivered food consumption than those who consumed fruits < 1 time/day (p = 0.0110). After adjusting for the confounding variables, the group who consumed delivered foods more than three times/week had an increased odds ratio (OR) of obesity compared to those who consumed less one time/week (OR, 2.38; 95% confidence intervals, 1.12–5.06). Conclusion Young adults in Jeju who frequently consume delivered foods tended to have poor dietary habits including skipping breakfast and eating salty, and they had an increased odds of obesity. The overall dietary patterns can be improved by providing nutrition education and developing policies to promote or support healthy food choices when ordering delivered foods or eating out.

Continuous renal replacement therapy (CRRT) has become the standard modality of renal replacement therapy (RRT) in critically ill patients. However, consensus is lacking regarding the criteria for discontinuing CRRT. Here we validated the usefulness of the prediction model for successful discontinuation of CRRT in a multicenter retrospective cohort. Methods: One temporal cohort and four external cohorts included 1,517 patients with acute kidney injury who underwent CRRT for >2 days from 2018 to 2020. The model was composed of four variables: urine output, blood urea nitrogen, serum potassium, and mean arterial pressure. Successful discontinuation of CRRT was defined as the absence of an RRT requirement for 7 days thereafter. Results: The area under the receiver operating characteristic curve (AUROC) was 0.74 (95% confidence interval, 0.71–0.76). The probabilities of successful discontinuation were approximately 17%, 35%, and 70% in the low-score, intermediate-score, and highscore groups, respectively. The model performance was good in four cohorts (AUROC, 0.73–0.75) but poor in one cohort (AUROC, 0.56). In one cohort with poor performance, attending physicians primarily controlled CRRT prescription and discontinuation, while in the other four cohorts, nephrologists determined all important steps in CRRT operation, including screening for CRRT discontinuation. Conclusion: The overall performance of our prediction model using four simple variables for successful discontinuation of CRRT was good, except for one cohort where nephrologists did not actively engage in CRRT operation. These results suggest the need for active engagement of nephrologists and protocolized management for CRRT discontinuation.

Purpose: This study evaluated the nutrition and food intake status among adults in Jeju, Republic of Korea, based on their sociodemographic characteristics and obesity. Methods: Nine hundred and forty-nine adults aged 19 years or older were included based on the 2022 Jeju Nutrition and Physical Activity Survey data. A dietary assessment was conducted using a one-day, 24-hour recall method, and the nutrition status was evaluated using the 2020 Dietary Reference Intakes for Koreans. The sociodemographic status included sex, age, education, and household income, and obesity was defined as a body mass index (BMI) of ≥ 25 kg/m 2 . Results: The mean age of the subjects was 49.8 years, and the overall prevalence of obesity was 48.4% (59.5% for males and 37.2% for females). The top three insufficient nutrients consumed at less than the estimated average requirement were calcium (77.7%), vitamin A (77.3%), and vitamin C (61.3%), while 40.9% of the subjects consumed fat as more than 30% of their total energy intake. The sodium intake was approximately 1.5 times higher than the chronic disease risk reduction intake level. In terms of food groups, the participants consumed more meat (148.2 g/day), seafood (69.0 g/day), potatoes, and starches (41.6 g/day) but consumed fewer vegetables (214.3 g/day) and less dairy (62.0 g/day) than Korean adults. The nutritional status and food intake patterns differed by the sociodemographic status. In addition, the obese group consumed more poultry and beverages than the non-obese group (p < 0.05 for all). Conclusion Adults in Jeju under-consume essential nutrients while over-consuming certain nutrients, such as fat and sodium. The nutritional status also varied according to the sociodemographic characteristics. These findings suggest that sociodemographic factors should be considered carefully when developing nutritional policies and programs to improve the nutritional status and address obesity among adults in Jeju.

Objectives: Recently, food insecurity has been a major public health issue along with the food crisis caused by COVID-19, climate change, and the polarization of food supply due to socioeconomic disparities. Food insecurity is known to be related to the food choices and environment of the consumer. Therefore, this study aimed to evaluate the food security statuses of adults in Jeju and investigate their food purchase patterns, food policy recognition, and food environment satisfaction. Methods: Based on data from the 2022 Jeju Food Survey, 346 adults aged ≥19 years in Jeju were classified into food security and insecurity groups (quantitatively and qualitatively) using the questionnaire. Food purchase patterns, including purchasing frequency, items, and reasons, were surveyed for local and eco-friendly foods. The recognition and necessity of several food policies and satisfaction with diet and food environment (availability, accessibility, affordability, accommodation, and acceptability) were measured using the Likert scale. Results: Among the total participants, 47.4% were in the food insecurity group. The frequency of purchasing local and eco-friendly foods did not significantly differ by food security status. The insecurity group exhibited a higher recognition rate of basic rights to food (36.0%) than the security group (24.7%, P = 0.023). The recognition and necessity of specific food policies did not significantly differ by food security status, except for the policy of promoting food communities, for which the food security group exhibited higher recognition than the food insecurity group did (P = 0.004). The food insecurity group exhibited significantly lower scores regarding satisfaction toward diet and food environment factors (P < 0.05 for all). Conclusions Overall, the food security group reported higher satisfaction with their diet and food environment than the food insecurity group. Further in-depth studies to investigate the determinants of food insecurity and effective promotional strategies for food policies are needed.

Purpose: Proteins are major components of the body and essential nutrients for proper growth and development. However, studies on protein intake in children and adolescents are insufficient. A few previous studies have reported the relationship with growth indicators, but results vary depending on the source of protein. Therefore, the current study investigates the relationship between protein intake and overweight and obesity among children and adolescents in Korea. Methods: Based on the 2014–2019 Korea National Health and Nutrition Examination Survey, 5,567 children and adolescents aged 6–18 years, who participated in a 24-hour dietary recall with information on height and weight, were included in this study. Protein intake was estimated as percentage of total energy (% of energy) and was classified into animal and plant protein according to the food source. Overweight and obesity were defined using the 2017 pediatric and adolescent growth chart. Results: Total protein intake of the subjects was estimated as 14.5% of total energy (animal protein 8.3% and plant protein 6.3%). The group with the highest total protein intake had a higher odds ratio (OR) of overweight/obesity than those with the least protein intake (OR, 1.36, 95% confidence interval (CI), 1.10-1.67, p for trend = 0.003). When classified by food source, the group with the highest animal protein intake had a significantly higher OR of overweight/obesity than subjects with the lowest intake (OR, 1.30, 95% CI, 1.05-1.61, p for trend = 0.016). However, plant protein was not significantly associated with overweight/obesity. Conclusions These findings suggest that a high intake of animal protein in children and adolescents increases the risk of being overweight and obese. In order to develop normal growth and prevent obesity in the future, it is necessary to determine an appropriate protein intake level through nutrition education programs and prospective studies on balanced protein intake.