Discussion
This article examines the components of the DOHaD awareness scale and investigates its development and validity as a reliable tool for assessing awareness of DOHaD concepts among university students and furthermore, it explores whether participation in an educational module related to these concepts influences dietary behaviors, physical activity levels, and the overall understanding of DOHaD among this demographic. As a result of the study, a reliable and valid instrument has been developed to assess awareness of DOHaD concepts among university students. Our results indicated a positive association between a single DOHaD education module and short-term improvements in anthropometric measurements, healthier eating parameters, light to moderate physical activity levels, and understanding of DOHaD concepts among participants. These parameters were evaluated at two different time points during the study period. These were 6 weeks and 6 months after the educational module. The results suggested initial improvements in anthropometric measurements, HEI-2015 scores, and physical activity levels, with some metrics maintained or modestly enhanced 6 months after the education module. The educational intervention was shown to increase only light to moderate physical activity. The lack of change in intense exercise may be attributed to barriers related to perceived difficulty, individual fitness levels, and external factors. It is advisable for future research and interventions to address these issues. These outcomes indicated that DOHaD concepts were associated with improved health behaviors in college students, with some of these behaviors observed to persist over a 6-month period. This study contributes to understanding DOHaD awareness levels among university students and highlights areas for further investigation. By developing the DOHaD awareness scale, it provides a validated tool for assessment in this demographic. The study suggests educational interventions may be valuable in promoting healthier lifestyle choices among university students, although further research is needed.

Since the first proposition of DOHaD hypothesis, the accumulated outcomes of several laboratory and clinical research point out the necessity of translating current evidence into practice but few studies suggested that women of reproductive age were not aware of the importance of early life nutrition and impact of maternal environment on growth and development of the baby adequately. A large-scaled study undertaken in five European countries with 2,071 first-time mothers reported that diet as an infant was considered to be a less important influence on lifelong health than many lifestyle, behavioral, and environmental factors and genetics ( Gage et al., 2011 ). When the evidence of the link between maternal diet quality and diet quality of the offspring at the age of 14 is considered ( Bjerregaard et al., 2019 ), the wide perspective of DOHaD knowledge appears to have a great potential of preventing unhealthy lifestyle factors. Recent studies emphasize the necessity of focusing on prevention rather than treatment to break the cycle of NCDs ( Tohi et al., 2022 ). One study conducted by McKerracher et al. (2020) developed and applied the DOHaD KNOWLEDGE scale in pregnant women and reported that diet quality during pregnancy was positively associated with DOHaD KNOWLEDGE after adjusting for sociodemographic factors. Although the DOHaD KNOWLEDGE scale introduced a set of data regarding the knowledge level related with DOHaD concepts, it consisted of five positively phrased items and targeted at pregnant women. The internal reliability of DOHaD KNOWLEDGE scale was found be satisfactorily high and for this reason authors concluded that a coherent mental construct was obtained. The need and importance of measuring and constituting baseline awareness of DOHaD concepts through systematic tools is reported, previously ( Bay et al., 2017 ; Oyamada et al., 2018 ; McKerracher et al., 2020 ). The DOHaD hypothesis is based on several mechanisms including factors associated with epigenetics, inadequate and unbalanced nutrition, paternal health and mother’s well-being at different stages of the reproductive period such as pre-pregnancy, pregnancy and lactation. Therefore, in the DOHaD awareness scale we aimed to establish a comprehensive list of items which comprise a wide perspective of DOHaD concepts to initiate or determine an awareness level. The study successfully produced a reliable and internally consistent tool for the defined purposes.

DOHaD education exerted positive effects on the perception of the statements “The food I eat now (11–14 years of age) will affect my health in the future” and “The food a woman eats when she is pregnant affects the health of her baby when it is grown up” as the percentage of the “strongly agree” responses increased in a study conducted on adolescents ( Bay et al., 2012 ). Another study conducted by Oyamada et al. (2018) reported that the awareness levels of the students about the concepts of “DOHaD concept” and “First 1,000 days” increased significantly after DOHaD training in college students. Similarly, the initial scores of DOHaD awareness scale revealed a modest understanding of the DOHaD concepts since the average baseline score was 69 in the current study. The three items belonged to the questions 13, 14 and 20 (“How much does a pregnant woman’s nutrition during pregnancy affect the health of the fetus in adulthood?”, “How much does a pregnant woman’s nutrition during pregnancy affect the health of the fetus in elderly?”, and “How much can a pregnant woman’s nutritional status during pregnancy affect the health of the next generations by changing gene functioning?”, respectively) had the lowest scores before the education module but at the end of 6 months the scores belonged to these items revealed a greater understanding. These questions are composed of the core understanding of DOHaD concepts. Especially question 20, which interrogated the knowledge of epigenetics, introduced one of the most significant component of DOHaD awareness scale but this item had the lowest score at 6 months after the treatment. It is known that epigenetics is currently one of the most attractive field of developmental biology and the methods used to link environmental factors and development of chronic diseases through epigenetic mechanisms will be accessible in near future ( Lynch et al., 2022 ). The importance of appealing public interest to the understanding of epigenetics was specified, previously ( Lynch et al., 2022 ). Therefore, we believe that tools like DOHaD awareness scale can help to take attention of public to the topic of epigenetics and its fundamentals.

Educational approaches are among the most effective methods for implementing preventive initiatives aimed at enhancing individuals’ knowledge of DOHaD ( Tohi, Tu’akoi & Vickers, 2023 ). Nutrition education programs and behavior change interventions can improve the knowledge and implementation of healthy eating practices ( Mahumud et al., 2022 ). In this context, HEI has been considered a useful tool to assess the effectiveness of nutrition intervention programs in different studies. Expanded Food and Nutrition Education Program participation resulted in improved outcomes of HEI scores in a study involving on 97,552 participants ( Gills et al., 2021 ). A consumer education programme increased HEI component scores for total fruit, whole fruit, whole grains, saturated fat, and energy from solid fats, alcohol, and added sugars significantly ( Glanz et al., 2012 ). The influence of DOHaD education modules on HEI parameters is not well-known since previous studies evaluated the link between diet quality and DOHaD education used either subjective statements on eating behaviors ( Bay et al., 2012 , 2017 ) or different tools. Bay et al. (2012) suggested the use of more substantial diet quality indicators to examine the influence of intervention in detail. McKerracher et al. (2020) reported that maternal diet quality which was calculated with Prime Screen©Food Frequency Questionnaire was positively associated with DOHaDKNOWLEDGE. They concluded that higher familiarity with DOHaD concepts resulted in greater diet quality during pregnancy. In the current study, HEI-2015 was used due to its reliable and generalisable properties. HEI-2015 scores of the participants significantly improved in the current study at 6 weeks and 6 months after the DOHaD education module. This effect can be explained through the motivational effect of DOHaD knowledge on positive behavioral changes. These findings highlight the potential importance of DOHaD awareness in promoting healthy lifestyle habits.

The effect of nutrition education programs and behavior change interventions on anthropometric measurements and physical activity levels has also been reported ( Barrett et al., 2021 ). To date, none of the studies have evaluated the effect of DOHaD knowledge on anthropometric measurements and physical activity levels. In line with HEI-2015 scores, the participants in the current study exhibited healthier anthropometric measurements and physical activity levels at 6 months after the education module in comparison to pre-intervention period. These results indicate a coherent influence of DOHaD education on behavior change towards a healthier lifestyle. Although there are studies in the literature in which significant weight loss is achieved with single education session, this situation should not be considered a decisive point for maintaining the ideal body weight in long term ( Bhurosy & Jeewon, 2013 ; Wadolowska et al., 2019 ). Therefore, it is very crucial to provide healthy nutrition education to the public at regular intervals and to ensure their sustainability. At this point, the implementation of DOHaD concepts into practical advice with measurable goals is critically important.

The results obtained from the GEE analysis indicate that both the DoHaD awareness scale and HEI-2015 scores have a substantial impact on the anthropometric outcomes over time, with their interaction being critical for changes in the dependent variables. The AR(1) correlation structure indicates a diminishing correlation between repeated measurements over time, which is characteristic of longitudinal data. The multivariate regression analysis reveals that the waist-to-height ratio plays a significant role in influencing awareness of the DOHaD, emphasizing the relevance of abdominal fat distribution. This finding supports the notion that health risks associated with abdominal obesity increase awareness. Other anthropometric measurements and Healthy Eating Index (HEI) scores did not show a significant relationship with DOHaD awareness, and time did not have a notable effect, implying that awareness tends to remain stable. In summary, specific indicators such as the waist-to-height ratio affect health awareness, while other factors illustrate the complexity surrounding this issue.

The current study has several limitations that should be considered for future research involving the DOHaD awareness scale. First, the sample in this study consists solely of first-year nursing students, who may have a heightened concern for maintaining a healthy lifestyle. The sustained improvement in dietary quality and anthropometric measurements observed six months after the educational module may not solely reflect the impact of DOHaD concepts, but could also be influenced by the participants’ overall attentiveness to health. Conducting the study without a control group limits the attribution of the findings solely to the educational module, independent of external factors, which may restrict the generalizability of the results. Therefore, there is a clear need for additional studies that explore the effectiveness of the DOHaD awareness scale within the broader population.

Future research should include a control group that does not receive the DOHaD educational module or any other intervention. This would allow for comparisons with the intervention group and help isolate the effects of the educational intervention from other external factors.

Additionally, to validate the robustness and generalizability of the results, studies should be conducted with participants from multiple locations or schools, including different genders, various academic disciplines, and different age groups.