Consumption Patterns of Ultra-Processed Foods and Fruits·Vegetables and Their Association with Nutritional status and Frailty Among Korean Adults

다국어 초록 (Multilingual Abstract)

Background & Objectives: Modern dietary transitions have led to increased consumption of ultra-processed foods (UPFs) and insufficient intake of fresh fruits and vegetables (FV), both of which are critical determinants of health in aging populations. This study aimed to analyze consumption patterns of UPFs and FV and to investigate their associations with nutritional status and the risk of frailty among Korean adults. Methods: Data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES). The study population comprised adults aged 40 years and older, to assess frailty using a modified Fried phenotype. UPFs intake was classified according to the NOVA system, and dietary versus supplemental vitamin C intake was evaluated in relation to FV sufficiency. Multivariable logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for frailty. Results: High UPFs consumption was associated with higher energy intake but lower micronutrient density across all age groups. Total UPFs intake was significantly associated with an increased risk of frailty (OR = 1.52, 95% CI: 1.326–1.749 for the highest quartile). However, the risk varied by food source; grain- and beverage-based UPFs increased frailty risk, whereas legume-based UPFs showed an inverse association. Regarding vitamin C, a significant proportion of adults had insufficient FV intake. While supplements helped meet vitamin C requirements, they did not confer the same protective benefits against frailty as dietary sources. High intake of FV and dietary vitamin C was significantly associated with a lower risk of frailty (OR = 0.49, 95% CI: 0.286-0.844 for FV; OR = 0.64, 95% CI:0.425-0.966 for dietary vitamin C), particularly in women. Conclusion: These findings suggest that both the quantity and qualitative source of food intake are crucial for healthy aging. While UPFs generally exacerbate nutritional imbalances and frailty risk, specific UPFs subgroups may have differential effects. Furthermore, improving overall diet quality through sufficient FV intake is more effective for preventing frailty than relying on single-nutrient supplementation. Public health strategies should prioritize whole-food-based approaches to improve nutritional status and prevent frailty in older adults.

목차 (Table of Contents)

• Chapter 01. Background and Objectives 1
• 1.1 BACKGROUND 2
• 1.2 RESEARCH OBJECTIVE 5
• Chapter 02. Consumption of Ultra-Processed Foods, Major Contributing Foods and Their Association with Frailty 6
• Ⅰ. INTRODUCTION 7
• Ⅱ. SUBJECTS AND METHODS 10
• 2.1 Data and participants 10
• 2.2 Food Classification using Korean version of NOVA system 12
• 2.3 Assessment of frailty 16
• 2.4. Other variables 17
• 2.5. Statistical analysis methods 18
• Ⅲ. RESULTS 19
• 3.1 General characteristics of older adults, and oldest-old adults 19
• 3.2 General characteristics of the subjects according to
• the level of UPFs intake 22
• 3.3 Frequency and proportion of NOVA food group intake according to the level of UPFs intake 25
• 3.4 Nutrient intake according to the level of UPFs intake by age group 27
• 3.5 Food group intake according to the level of UPFs intake by age 31
• 3.6 Energy intake from each food group according to the level of UPFs intake 35
• 3.7 The contributions of each UPFs-based food group to total energy intake 39
• 3.8 Major foods contributing to UPFs intake by age 41
• 3.9 Major UPFs consumed within each food group by age 43
• 3.10 The risk of frailty by total UPFs intake 47
• 3.11 Association between frailty and UPFs intake within each food group 49
• Ⅳ. DISCUSSION 51
• V. CONCLUSION 58
• Chapter 03. Patterns of Dietary and Supplemental Vitamin C Intake According to Fruit and Vegetable Consumption and Their Association with Frailty 59
• Ⅰ. INTRODUCTION 60
• Ⅱ. SUBJECTS AND METHODS 62
• 2.1 Data and participants 62
• 2.2 Assessment of frailty 66
• 2.3 FV Intake 67
• 2.4 Dietary and supplemental Vitamin C intake 67
• 2.5 Other variables 68
• 2.6 Statistical analysis methods 69
• Ⅲ. RESULTS 70
• 3.1 General characteristics of subjects by age and FV sufficiency 70
• 3.2 The characteristics of the subjects according to frailty 73
• 3.3 Dietary and supplemental vitamin C intake and prevalence of vitamin C sufficiency according to FV sufficiency 76
• 3.4 The distribution of FV and vitamin C intake according to frailty status 80
• 3.5 Mean dietary vitamin C intake according to the food groups and its contribution to the dietary vitamin C intake 82
• 3.6 Major food sources of dietary vitamin C by FV and dietary vitamin C sufficiency 84
• 3.7 Risk of vitamin C insufficiency by FV sufficiency and vitamin C supplement use 87
• 3.8 The risk of frailty according to source of vitamin C intake 89
• 3.9 The risk of frailty by FV adequacy and vitamin C supplement use 91
• Ⅳ. DISCUSSION 93
• V. CONCLUSION 99
• Chapter 04. Summary and Conclusion 100
• 4.1 SUMMARY 101
• 4.2 CONCLUSION 104
• REFERENCE 106
• Abstract (Korean) 119