National prevalence and trends in food labeling awareness, comprehension, usage, and COVID-19 pandemic-related factors in South Korea, 2014–2022

Although food labeling on food packages is crucial for promoting a healthy diet, limited research has been conducted on how the COVID-19 pandemic (hereinafter “the pandemic”) has affected food labeling awareness. Therefore, this study aims to analyze the changes in trends in food labeling awareness, comprehension, and usage in South Korea during the pandemic. We utilized a nationwide, large-scale, and long-term dataset provided by the Korea Community Health Survey (KCHS) from 2014 to 2022 (total = 1,756,847 participants). This allowed the researchers to assess the long-term trends in the prevalence of food labeling awareness, comprehension, and usage. Furthermore, we investigated the factors associated with awareness specifically related to the pandemic. In total, 1,756,847 adults (54.19% women) participated in this study. The upward slope in overall food labeling awareness became less pronounced and even exhibited a downward slope during the pandemic (βdiff − 1.759; 95% CI − 1.874 to − 1.644). The upward slope in food labeling comprehension and usage became more pronounced during the pandemic (comprehension: βdiff 0.535; 95% CI 0.436–0.634; usage: βdiff 0.693; 95% CI 0.601–0.785). The vulnerability factors associated with lower food labeling awareness during the pandemic included older age, male, obesity, residing in rural areas, lower household income, lower educational level, smoking, and increased alcohol consumption. This study analyzed the 9-year trend in the prevalence of food labeling awareness, comprehension, and usage based on nationally representative data of adults in South Korea from 2014 to 2022. Our findings suggest that personalized nutrition strategies are needed to recognize vulnerable groups with risk factors and improve food labeling awareness among Korean adults during the pandemic.

differences in β-coefficients were estimated to assess the variations in trends between the before and during pandemic periods 4,25 .All β-coefficients and any differences between them were multiplied by 100 to simplify comprehension.To minimize the impact of potential confounders, all models utilized the following adjusting variables: age group, sex, BMI group, residential area, household income, educational level, smoking status, alcohol consumption, and subjective health level (Supplementary material).Additionally, to address the potential relationship between one or more regressors and the error variance, the Eicker-White heteroskedasticityconsistent estimator was used to estimate standard error values (Tables S2-S4).
A multivariate logistic regression model was used to analyze the coverage from 2019 to 2022 (2020 versus 2019, 2021 versus 2020, and 2022 versus 2021; Tables S5-7) and to express the ratio of Odds Ratios (OR) with a 95% CIs for identifying factors associated with vulnerability to food labeling awareness during the pandemic 26 .To ensure the representativeness of the study, a survey weighting analysis was conducted using KCHS's unique weighting system, household weighting, for all analyses.This assesses the household extraction rate by incorporating the sample extraction process in sample design, the rate of households suitable for the survey, and the distribution of households based on housing types.The statistical significance was defined as a two-sided p-value less than 0.05.Statistical analyses were performed by utilizing the SAS software (version 9.4; SAS Inc., Cary, NC, USA).
Tables 2, 3, and 4 present the changes in trends regarding the proportion of individuals who reported awareness of the presence of food labeling on the products they buy, those who read and comprehend the labeling on the food, and those who make use of the food labels when buying products, respectively.All trends exhibited a constant rate of growth in awareness, comprehension, and utilization of food labeling (Fig. 1).

Findings of our study
This study analyzed the 9-year trend in the prevalence of food labeling awareness, food labeling comprehension, and food labeling usage based on nationally representative data from adults in South Korea from 2014 to 2022.The overall prevalence of food labeling awareness, food labeling comprehension, and food labeling usage exhibited a continuously increasing trend.Unlike the trend of before the pandemic breakout, there was a deceleration in the trend slope of nutrition label awareness, indicating a slower rate of increase during the pandemic period from 2019 to 2022.On the other hand, the trend slope of food labeling comprehension and usage accelerated, indicating a faster rate of increase during the same period of pandemic.The pandemic-related vulnerability factors of food labeling awareness were older age, male, obesity, residing in rural area, lower household income, lower educational level, smoking, and increased alcohol consumption.This study's findings suggest personalized nutrition strategies, such as educating the importance of a balanced diet to recognize vulnerable groups with risk factors, and to improve food labeling awareness among Korean adults after the pandemic breakout.

Comparison with previous studies
Few studies have investigated food labeling awareness or the determination of vulnerability factors.A previous Korean study on the prevalence of food labeling reported a constant increase in awareness and utilization of food labeling from 2014 to 2017 18 .However, this study only analyzed a short period (2014-2017) that did not include the pandemic period.In addition, studies conducted in China investigating the current food labeling knowledge, attitude, and practice 27 only conducted a survey in a single city with a small sample size (n = 636) and cross-sectional design, and were unable to demonstrate any trend changes.A study conducted in the USA analyzed the food labeling usage of participants with chronic diseases 28 .However, this study exclusively focused on participants with chronic diseases, limiting its ability to provide insights into food labeling usage among the general population.In addition, a study from Italy discovered that most people do not use food labeling completely consciously and that simplifying the label format would help people with no expertise to read the labeling 8 .However, the small sample size and short observation period has a difficulty showing the trend of the

Possible explanations
The constant increase of food labeling awareness, comprehension, and usage despite the unchanging food labeling system may be explained by increasing interest of people towards maintaining a healthy diet.The deceleration of awareness increases and the acceleration of the increase in food labeling comprehension and usage may be attributable to quarantine and social distancing 29 .A study conducted in Korea revealed that there was a substantial rise in the volume of business for food services (839.7%),food and beverage (203.8%), as well as agricultural goods, meat, and fish products (193.5%)from 2017 to 2021 30 .As a result of the pandemic, a greater number of individuals have resorted to shopping for groceries through the internet (also referred to as online shopping).This movement might have likely hindered the increase in food labeling awareness, as fewer individuals see the product in person and inspect the nutrition label 31,32 .Additionally, after selecting the product and delivering it, examining the package becomes irrelevant, thereby reducing the increase in awareness.However, individuals who were already aware of food labeling might have become more active in reading and utilizing food labeling, as the pandemic has heightened people's interest in maintaining a healthy diet 33 .Furthermore, because of the COVID-19 quarantine, a greater number of individuals have started cooking meals at home as opposed to dining out 32,34 .This shift in behavior may have led to an increase in comprehension and usage of food labeling.

Policy implication
As previous studies have not analyzed the differences in food labeling awareness before and during the pandemic, they exhibit a somewhat optimistic view of the trend in food labeling awareness 18,33 .However, this study's results

Continued
imply that the pandemic has negatively influenced the overall awareness of food labeling, necessitating further efforts to increase its awareness 21 .There is no specific advertisement that would assist in increasing the awareness of food labeling.Food labeling awareness significantly affects whether a consumer can maintain a healthy diet when required.Another suggested policy is the front-of-pack labeling (FOPL) 35 .It indicates that people with lower socioeconomic status (defined according to participants' education, income, areas of residence or the store's location) are affected more by FOPL.Policymakers should recognize that the pandemic negatively affected people's food labeling awareness and that efforts must be made to provide citizens with the right information on the label of food packages [36][37][38] .

Strength and limitations
This study included a large-scale, nationally representative, and long-term serial survey that covered the pandemic period (2019-2022).However, there were limitations to this study that should be considered.First, the data utilized by the researchers were missing for people who did not answer all the questions related to the covariates used in this study.The missing data may lead to a biased interpretation of the data as the missing data may have similar factors 4,39 .Second, while this study contained data from the pre-pandemic (2014-2019) to the pandemic (2020-2022) period, it did not contain data from the post pandemic (2023-) period 40 .Further research of food labeling awareness, comprehension, and usage must be conducted to estimate the future trend.
Third, this research examines the trend of food labeling awareness, comprehension, and usage before and after the pandemic, but does not examine the causal relationship between the two factors.Therefore, further research must be conducted to examine the causal relationship and solve the fundamental problem of information inequality in food labeling.Finally, the dataset exclusively comprised individuals in Korea, thereby missing the consideration

Conclusion
This study elucidated that food labeling awareness, comprehension, and usage increased throughout the years of data collection.The COVID-19 pandemic negatively influenced food labeling awareness but positively impacted food labeling comprehension and usage.Through the identification of risk factors for food labeling awareness, www.nature.com/scientificreports/ it will be necessary to present a political solution to steadily increase food labeling awareness and bridge the gap between the groups.

Table 4 .
Prevalence of food labeling usage in the KCHS, 2014-2022 (n = 1,756,847).BMI body mass index, CI confidence interval, KCHS Korea Community Health Survey.The beta values were multiplied by 100 as a result of their minimal number.Numbers in bold indicate a significant difference (P < 0.05).*The model was adjusted for age (19 to 39, 40 to 49, 50 to 59, 60 to 69, and ≥ 70 years), sex, body mass index (BMI; underweight, normal weight, overweight, and obese), residential areas (urban and rural), household income (lowest quartile, second quartile, third quartile, and highest quartile), educational level (elementary school or less, middle school, high school, and college or more), smoking status (non-smoker, ex-smoker, and current smoker), alcohol consumption (below a day, once to four days, and five days or more per month), and subjective health level (high, normal, and low).

Table 1 .
Baseline characteristics of the participants in the KCHS, 2014-2022 (n = 1,756,847).BMI body mass index, KCHS Korea Community Health Survey, SD standard deviation.

2.146 (2.065 to 2.227) 0.796 (0.633 to 0.958) − 1.350 (− 1.532 to − 1.169)
Continuedgeneral population.Results from the present study provide long-term evidence demonstrating how the pandemic affected the awareness, comprehension, and usage of food labeling, which covered 1,756,847 participants and was collected over nine years.

Table 3 .
Prevalence of food labeling comprehension in the KCHS, 2014-2022 (n = 1,756,847).BMI body mass index, CI confidence interval, KCHS Korea Community Health Survey.The beta values were multiplied by 100 as a result of their minimal number.Numbers in bold indicate a significant difference (P < 0.05).*The model was adjusted for age (19 to 39, 40 to 49, 50 to 59, 60 to 69, and ≥ 70 years), sex, body mass index (BMI; underweight, normal weight, overweight, and obese), residential areas (urban and rural), household income (lowest quartile, second quartile, third quartile, and highest quartile), educational level (elementary school or less, middle school, high school, and college or more), smoking status (non-smoker, ex-smoker, and current smoker), alcohol consumption (below a day, once to four days, and five days or more per month), and subjective health level (high, normal, and low).Vol.:(0123456789) Scientific Reports | (2024) 14:2617 | https://doi.org/10.1038/s41598-024-51948-1www.nature.com/scientificreports/ 41 racial and cultural variances in the research41.Consequently, additional investigations should be conducted in countries with diverse cultural backgrounds.

Table 5 .
Pandemic-related factors of food labeling awareness in the KCHS, 2014-2022 (n = 1,756,847).CI confidence interval, BMI body mass index, KCHS Korea Community Health Survey, OR odds ratio.Numbers in bold indicate a significant difference (P < 0.05).*The model was adjusted for age (19 to 39, 40 to 49, 50 to 59, 60 to 69, and ≥ 70 years), sex, body mass index (BMI; underweight, normal weight, overweight, and obese), residential areas (urban and rural), household income (lowest quartile, second quartile, third quartile, and highest quartile), educational level (elementary school or less, middle school, high school, and college or more), smoking status (non-smoker, ex-smoker, and current smoker), alcohol consumption (below a day, once to four days, and five days or more per month), and subjective health level (high, normal, and low).∥The COVID-19 pandemic period versus the pre-pandemic period.