In 2024, chronic non-communicable diseases were responsible for an estimated 41 million deaths worldwide, accounting for 74% of all global deaths. Over 15 million of these deaths occurred among individuals aged 30 to 69 years. Cardiovascular diseases accounted for the highest number of deaths, followed by cancers, respiratory diseases, and diabetes. The causes of chronic non-communicable diseases are varied, stemming from a combination of genetic, physiological, environmental, and behavioral factors, including unhealthy diets and metabolic issues such as obesity. To mitigate the health, economic, and social burdens associated with these diseases, the World Health Organization (WHO) identifies reducing risk factors as a priority intervention area (1).

Food-based dietary guidelines (FBDG), represented in Hungary by the OKOSTÁNYÉR (Smart Plate)^®. Nutrition Guidelines, (2, 3) aim to ensure optimal energy and nutrient intake at the population level. They guide individuals toward healthier eating habits by providing practical advice on food choices, food groups, and dietary patterns. Dietary recommendations are a crucial element of dietary interventions that can help reduce the risk of chronic non-communicable diseases and inform their dietary therapy through various means, including public education, national public health programs, and modifying the food environment (2, 4).

However, recognizing the considerable diversity in individual nutritional needs, professional guidelines stress the importance of personalized approaches to dietary therapy (5–7). These approaches must assess and consider individual preferences, needs, and values. Patient-centered care (PCC) addresses these needs by ensuring that an individual’s values guide all clinical decisions, including those related to dietetic care (8, 9). Furthermore, an individual’s ability to acquire, understand, process, and apply health-related information, such as knowledge about healthy eating, is a fundamental determinant of the effectiveness of nutrition interventions (10).

Based on health literacy studies conducted in Hungary (11–14), it is likely that a significant portion of the target population for dietary interventions can only comprehend and act upon information and guidance, such as recommended dietary practices, with assistance. Recent studies have highlighted a significant prevalence of low health literacy (11, 12) among the Hungarian population, revealing concerning levels of both functional (14) and practical health literacy (13). These studies affirm the previously established connection between low health literacy and the development of chronic diseases. However, to date, there has been no research conducted in Hungary or elsewhere that specifically examines health literacy in relation to the presence of chronic diseases, dietary practices, consultations with dietitians, or awareness of local nutritional recommendations.

Patient-centered care, which benefits therapeutic outcomes and quality of life, is based on enhancing the patient’s self-management skills and competencies (9, 15, 16). This approach requires health professionals, including dietitians, to possess a solid understanding of the population’s health literacy. They must convey messages about nutrition therapy using effective communication tools that are tailored to the specific needs of the target audience.

This study aims to explore the relationship between health literacy, dieting, dietitian advice, and knowledge of the local FBDG. While the examination of nutritional habits, nutrient intake, and dietary adherence was not the primary focus of our research, it does suggest promising avenues for future investigation.

This survey was conducted in February 2023 with a representative sample of the Hungarian adult population, stratified by age, sex, and place of residence (N = 500). The data collection was carried out using the CAWI (Computer Assisted Web Interview) method, which allowed for online interviews.

The study employed the validated HLS-EU 47 questionnaire (17) that included demographic questions and assessed health literacy in three different domains: (1) health system-related literacy, (2) disease prevention, and (3) health promotion. Health literacy indices were defined using the methodology developed by the HLS-EU consortium, adhering to internationally validated thresholds (18). The European Health Literacy Survey (HLS-EU) was developed following the methodology outlined by Sørensen et al. (17). In the HLS-EU survey, 13 index thresholds were established in line with standard practices for measuring health literacy. These thresholds were designed to ensure that the correlation patterns between health literacy levels and significant covariates differed only minimally from the metric health literacy scores, while maximizing the correlation between the levels and the metric scores. The resulting four categories were defined as follows: “insufficient” (0–25), “problematic” (> 25–33), “sufficient” (> 33–42), and “excellent” (> 42–50) health literacy (18).

This study successfully applies the overall index and its three sub-indices to the Hungarian sample, and the analysis of the scale’s internal consistency confirms its reliability. The Cronbach Alpha values are particularly high, exceeding 0.9 for all indices. The Cronbach-α value was considered, which quantifies internal consistency, to be acceptable if it is between 0.70 and 0.96. The reliability of the overall health literacy index is confirmed by the Cronbach’s alpha value of 0.960. The validated health literacy scale contains 3 dimensions. The health subscale is measured with 16 items on a 1–4-point scale. The internal consistency of the subscale is confirmed by the high Cronbach’s alpha value of 0.904. Health prevention is measured using a 15-item subscale, whose internal consistency is reliable, with a Cronbach’s alpha value of 0.901. The third subscale is health development, for which 16 items were used. The reliability of the subscale is supported by the value of the coefficient 0.919.

Descriptive statistical indicators, such as mean, standard deviation, and frequency, were calculated to characterize the variables in the quantitative research. Bivariate statistical methods were utilized to examine the relationships between independent and dependent variables. The chi-squared test was used to explore correlations among categorical variables, including socio-demographic characteristics and specific health determinants (such as chronic diseases, following a diet, nutritional advice received from a dietitian, and knowledge of the local FBDG) concerning health literacy levels. The variables and measurement tools used in the study are listed in Table 1.

A one-way analysis of variance (ANOVA) was conducted to investigate the effect of nominal variables with two or more categories on metric variables. The assumptions for ANOVA, including normality and homogeneity of variance, were verified using Levene’s test. This analysis was appropriate for determining differences in scores across health literacy sub-indices between the two health literacy clusters (limited and adequate health literacy).

Multivariate regression models were employed to assess the impact of explanatory and control variables on the development of health literacy sub-indices and the overall health literacy index. These regression models were evaluated using F-tests, while individual regression coefficients were tested with t-tests. The condition of multivariate regression analysis—specifically, the absence of multicollinearity—was assessed through the correlation coefficients presented in the correlation matrix.

Results were deemed significant at p < 0.05, with a 95% confidence interval. Data were recorded and processed using SPSS version 27.0.

Participation in the online study was voluntary and contingent upon signing a consent form, following verbal and written information provided to participants. The study adhered to the principles outlined in the Declaration of Helsinki. Ethical clearance for the study was obtained from the Medical Research Council (Reference Number: BMEÜ/333-3/2022/EKU).

The importance of nutrition in enhancing health and quality of life, as well as in preventing and managing chronic diseases, is clear. Maintaining a healthy dietary pattern throughout one’s life helps prevent malnutrition and its various forms, which include non-communicable diseases such as obesity, type 2 diabetes, and cardiovascular diseases. While the basic principles of a varied, balanced, sustainable, and healthy diet remain consistent, individual nutritional needs can differ based on personal characteristics (1, 19, 20). FBDGs are designed to promote optimal energy and nutrient intake at the population level; however, they should also be personalized to address specific dietary needs for disease prevention or medical nutrition therapy (5).

PCC acknowledges and respects the unique needs, values, preferences, and socio-ecological and psychological characteristics of individuals, while positioning them at the core of healthcare (21). The patient-centered approach can enhance the quality of collaboration between patients and dietitians and build trust in healthcare professionals. As a result, it can lead to improved adherence to treatment and a better quality of life for patients (22).

PCC builds on the patient’s capability for informed and responsible decision-making, their ability to effectively self-manage and cope with the therapy. For patient-centered care to be a reality, patients must acquire the skills necessary for effective collaboration in which improvement of health literacy plays a key role (10, 21).

Results of this research indicate that the health literacy level among the Hungarian adult population presents significant gaps, which may serve as a major barrier to the prevention and management of chronic diseases. Over three-quarters of the sample (77.4%) can be classified as having “inadequate” or “problematic” health literacy, confirming the assumption that a substantial portion of the population struggles to interpret and apply health information. These findings align with other national and international studies that have reported similarly low levels of health literacy (11–14, 18, 23).

In the present study, the explanatory power of the independent variables included in the analysis is relatively small. Therefore, it is worthwhile comparing the results with those of previous studies, (12, 18) where the same method was used. Based on the Hungarian results, 15 percent of health literacy was explained by the socio-demographic explanatory variables built into the model (gender, age, educational attainment, material deprivation and social status). From an international perspective, higher explanatory power was found in Bulgaria (25%), Greece (29%), and Poland (21%). This figure was somewhat lower in Ireland (19%) and even weaker in Austria (10%), Germany (8%), Spain (9%) and the Netherlands (8%).

Regarding factors influencing health literacy, educational attainment demonstrated a notable association with domains such as prevention, the healthcare system, and overall health literacy. Respondents with higher levels of education exhibited higher health literacy compared to those with only primary education. Our research findings align with previous studies, both domestic (11–14) and international (18, 23), indicating that low educational attainment correlates with lower health literacy. The previous studies (12, 18) found that higher levels of health literacy were associated with being female, being younger, having a higher level of education and having a higher income. In the linear regression model, the effect of the independent variables on overall health literacy was expressed using standardized regression coefficients. For Hungarian respondents, the effects were as follows: gender, 0.08; age, −0.10; educational attainment, 0.15; and financial deprivation, −0.24. In an international comparison, the coefficient value for age ranged from 0.09 to 0.17. In countries where age was a significant explanatory variable, younger people had a higher health perception. However, age does not affect health perception in Germany, Ireland and the Netherlands. The regression coefficients showing the effect of educational attainment in the eight countries included in the study range from β = 0.08 to β = 0.22. Increased educational attainment increases health literacy in all countries except Austria and Ireland, where no significant relationship was found between the two factors.

This highlights the crucial role of education in mitigating social inequalities, which includes addressing health literacy disparities. The early integration of knowledge related to health (including diet and lifestyle choices), into school education in a more explicit and practice-oriented manner can be an effective tool for improving health literacy, maintaining health, reducing chronic diseases, and enhancing cooperation with medical nutrition therapy in cases of existing diseases (24–26).

Age also showed an association with health promotion and overall health understanding, where older populations, aged 60–64 and 65 and above, demonstrated lower health literacy, which is consistent with the results of previous research (11, 14, 27, 28). Although our research did not investigate the underlying causes, previous studies (28–30) have identified several factors behind this phenomenon, such as social (e.g., lack of social support, isolation), sociodemographic (e.g., advanced age), economic (e.g., lower income) and health aspects (e.g., chronic conditions, reduced mobility, mental health challenges). A cross-sectional literature review was conducted by Battineni et al. (30) investigating factors affecting the quality and reliability of online health information. They found that older adults prefer direct visits with doctors and healthcare professionals and are less interested in accessing online health information. Poor health literacy among older adults is a complex issue that involves not only communication and information acquisition but also requires a multifaceted solution. This solution must involve public health programs as part of a comprehensive national health promotion strategy. Health professionals, including dietitians, need to develop the skills necessary to educate older adults with low health literacy effectively. Furthermore, when providing nutritional recommendations, it is essential to create approaches that are tailored to inform vulnerable individuals with low health literacy, focusing on improving the method of delivery, presentation, and clarity of wording.

An analysis of sub-indices revealed that individuals with low health literacy particularly struggle with assessing the reliability of information related to the health system and disease prevention. This is concerning, as reducing the risk of chronic diseases heavily relies on individuals recognizing and utilizing information from credible sources (31). Additionally, those in the low health literacy group exhibit a higher prevalence of chronic diseases and are less aware of the Hungarian dietary recommendations, which are crucial for prevention and dietetic communication.

The examination of sub-indices also revealed that respondents with limited health literacy experienced the most significant difficulty in assessing the reliability of health information obtained from the media. Survey data shows that sources of health-related information are increasingly shifting to digital channels. According to Eurostat data (32), the share of individuals seeking health information online has increased in almost all EU Member States over the last decade, rising by 17 percentage points in the EU from 38% (2011) to 55% (2022). In Hungary, this proportion was 65%. Technological advances have made it easier to access health information on the internet, but at the same time, they have increased the likelihood of encountering incorrect or unreliable health information. The low level of health literacy and the difficulty in assessing the reliability of health information found in the media are likely to be influenced by the issues discussed above, such as age and educational attainment, as well as lower digital skills (33). To enhance communication with patients who have low health literacy, various literature reviews highlight the significance of a multi-level approach, along with practical considerations such as language and visual presentation (34, 35). This indicates that, alongside individual therapeutic approaches like dietitian-patient consultations, we also need systemic measures involving health, education, and social systems, as well as societal measures such as public health strategies and community initiatives. Additionally, guidelines exist to enhance the quality of health information available on the internet, including the Suitability Assessment of Material guidelines and relevant literature reviews (36, 37). Which supports healthcare professionals in developing digital educative content for the general public.

The significant connection between the presence of chronic diseases and dietary adherence suggests that some individuals are more motivated to adopt lifestyle changes following a diagnosis. However, this study did not delve into this particular issue. This finding aligns with previous research (38), which indicates a lack of a preventive approach in Hungary, as a greater proportion of patients consult a dietitian only after a disease has been established, mainly upon the recommendation of a general practitioner or specialist.

Moreover, it is evident that the success of lifestyle changes and nutritional therapy is largely dependent on the individual’s level of health literacy. While chronic patients are more likely to seek dietary advice, a lack of skills in interpreting and applying this information can hinder effective intervention. The authors must acknowledge certain limitations of the study. The HLS-EU-Q47 tool assesses the perceived difficulty of a selected health task using a 4-point self-assessment scale (very easy, easy, difficult, and very difficult). This tool measures an individual’s health literacy by reflecting the balance between their personal competencies and the complexity or demands of various situations. It’s important to note that local factors, such as the healthcare system or patient pathways, can influence these perceptions. Therefore, when interpreting survey results, especially in international comparisons, these factors should be considered.

For collecting data, the CAWI is included in the HLS19 Study Protocol as being acceptable method (39). The data collection was carried out using an established online panel, which may lead to an overrepresentation of individuals with higher educational attainment and greater digital activity. This is evident in the sample, with individuals with low educational attainment making up only 3.6% of the total. Another limitation is the lack of weighting of the sample for population density (e.g., ethnicity). Furthermore, due to the cross-sectional design, causal relationships cannot be established.

The study has a significant strength: it is the first to explore the relationships between health literacy, dieting, the use of dietetic counseling, and awareness of the local food-based dietary guidelines (FBDG) within the Hungarian adult population, therefore offers valuable and new insights that can help improve dietetic practice.

Results of this study highlight the importance of PCC and personalized dietary approaches. If we do not consider the differences in health literacy among various populations, the effectiveness of nutrition counseling may be limited. The WHO emphasizes a collective responsibility for all information providers, including decision-makers, civil society, and health services, to ensure access to reliable health information that is comprehensible and actionable for everyone (10). Findings of this research can enhance dietary care in several ways. The first step in the dietetic intervention, known as the Nutrition Care Process (NCP), is the Nutrition Assessment (40). This step aims to evaluate an individual’s nutritional status by interpreting clinical information, which includes their medical history, dietary habits, and physical measurements. During this process, it would be beneficial to gather information about the individual’s health literacy. This can improve the effectiveness of medical nutrition therapy and patient education.

In healthcare, systematically screening for health literacy using appropriate tools can provide valuable insights for healthcare professionals. However, if screening is not feasible, professionals should still consider the risk of low health literacy among high-risk patients, such as those with low educational attainment, older individuals, or those from low socioeconomic backgrounds, and incorporate this into their care strategies. The concept of patient-centered dietary care, which takes into account the specific characteristics of health literacy, should be incorporated into healthcare guidelines and professional training curricula. It is essential to continuously review and develop dietary guidelines, including creating educational materials and communication tools (such as infographics and audiovisual content) that effectively reach populations with low health literacy.

The knowledge gained from our research, particularly through identifying at-risk groups, is also important for developing public health programs. This insight can contribute to creating more effective and inclusive prevention strategies.