A total of 365 dietetic students and professionals (46 in FGDs and interviews, 17 in face validity, 5 experts for content validity, and 297 in the validation testing) participated in the study. In the qualitative study, 80.4% were 18-25 years old, 19.6% had >10 years of work experience, and 26.1% had completed some kind of training/ certificate courses related to nutrigenomics. Out of 297 who completed the cross-sectional survey 92.3% were women, 24.3% belonged to the age category >35 years and 83.2% had at least a graduate degree in clinical nutrition (Table 1)
The results of the qualitative and quantitative data are provided separately in this section.
Results of the thematic analysis of FGD and IDI data
The FGD participants (n = 37) were between 20 and 23 years old, with a mean age of 21.61 ± 1.6 years. The majority of the experts in the interviews were women (95.7%), with at least a postgraduate degree (92.3%) and >15 years of experience working either in public hospitals (69.5%), private hospitals (23.8%), or own dietetic practice (6.7%). A summary of the main themes that emerged from the FGDs and IDIs is provided below:
Theme 1: Knowledge and understanding about nutrigenomics- The majority defined nutrigenomics as “the effect of food on your genes”, “interaction between the genes and nutrients”, and ‘mechanisms that show how food affects the gene expression”. When prompted to describe the specific genes that the participants were familiar with, the dietetic students mentioned “FTO gene for obesity”, “genes that are unique in people with caffeine sensitivity” and “OB gene”.Different chronic diseases where an application of PN might prove helpful were pointed out as“cancer”, “diabetes”, “cardiovascular diseases”, “autoimmune diseases”, “PCOS”, “Down syndrome” and “amino acid metabolic disorders”. A practicing dietitian mentioned PN as “a tailored nutrition strategy that allows an individual to personalize meals and diets to stay fit, reduce weight and prevent chronic diseases”, and another participant referred to PN as “nutrition for the self ….diet that is compatible with an individuals’ genotype’.
Theme 2: Perceived role and relevance of PN in dietetic practice- The discussions revealed mixed responses such as “I think nutrigenomics is as personalized as one can get with nutrition management’, “PN is more important with regards to diseases that are hereditary” and that ‘we cannot change our genes but we can modify our choices and environment, so they are critical aspects to be considered while diet planning and counseling”. The gene-nutrient interactions were perceived to be “definite”, “adamant”, “irreversible”, and “likely to change according to one’s lifestyle and environment”. While a student voiced concern that ‘Knowing what my genes say is in fact scary….’, a registered dietitian mentioned that ‘results of genetic testing can make patients more anxious, so it can be counter-intuitive if not communicated properly’ and another participant expressed ‘why mess up your present by knowing what may happen in the future due to faulty genes’.
Theme 3- Confidence and Competency to Practice – Overall, all participants showed poor confidence in practicing nutritional genomics and acknowledged that they do not have enough knowledge and training to plan, interpret, and counsel patients based on their genetic testing results. Dietetic students showed eagerness to learn about basic genetics and applications in nutrition, and the nutritionists mentioned that “dietitian is the right person to practice nutritional genomics” and ‘they need to seize the opportunity and get trained in PN’.
Theme 4- Barriers and Facilitators of integrating PN into practice- Furthermore, the discussions explored the perceived barriers and facilitators of improved knowledge and practice in the fraternity. A few excerpts related to barriers to PN practice are provided below-
“Lack of knowledge of the practitioner itself is the main barrier here.” (Knowledge)
“It's not a very common practice and it's not very publicized, so the people do not even know or ask for it.” (Public Awareness)
“Only a handful of them are actually trained or specialized in this field.” (Training)
“There is a lack of exposure to nutrigenomics and precision nutrition in the curriculum.” And ‘We were never taught about genetics and applications in nutrition in school (curricular deficits)
“For me personally cost plays a very important role’ (Cost of testing)
“Most of the people will not be comfortable giving the genetic information, even if it's for their personal benefit.” (Ethics and Safety)
The perceived facilitators of behavior change included “integrate nutritional genomics in our syllabus”, “spread awareness through case studies”, “include testimonials of people who have practiced, followed, and observed improvements”, “create infomercials to demystify pros and cons of genetic testing”, “sensitize the entire medical fraternity about applications of PN beyond inborn errors of metabolism” and ‘design credited, full time academic programs in higher education settings of India that can provide skills and required training to students and dietitians’.
Theme 5 – Behaviour and practice of incorporating gene-based PN in patient counseling - Of all participants, there were only 4 participants who had prior training in nutritional genomics, and all these certifications were either gained through online courses or a self-administered review of the literature. None of the participants were actively practicing PN in their routine dietetic practice.
Results of development and validation of KAB- PN
Based on the analyses of the qualitative data and a review of the existing instruments, the first draft of 58 item KAB_PN including four sections- knowledge, attitudes, behavior, and willingness to practice was developed. Demographic characteristics such as sex, age, highest academic degree, occupation, and number of years of work experience were also included.
Face validity-. The results of the pilot testing of the first draft suggested that a majority of the items were relevant, clear, and easy to understand except for 3 items related to the ‘exosomes’, “omics technology, and the concepts of ‘candidate genes and genome-wide association studies’ in the knowledge section. These items were removed after mutual discussions and review of the questionnaire. The time taken by the participants of the face validity exercise (n=17) to complete the questionnaire was approximately 10-15 minutes.
Content Validity- The content validity of the instrument was tested by an expert panel (n=5). Each item in the questionnaire was graded separately for clarity, simplicity, and relevance, with a score of 1 indicating excellent content validity. Table 1 provides the item content validity index (I-CVI) and scale content validity index (S-CVI) scores for clarity, simplicity, and relevance for each item on the questionnaire. Based on the set criteria ICVI > 0.8 and SCVI >0.9, an additional two knowledge, and 4 attitude items were excluded, resulting in a 48-item questionnaire. INSERT SUPPLEMENTARY TABLE 1
Item Analysis- The results of the item analysis showed that the item difficulty indices ranged from 0.60 to 0.72 and the mean item discrimination index was 0.32 (Supplementary Table 1). INSERT SUPPLEMENTARY TABLE 2
Construct Validity- The initial CFA results indicated a model misfit for the hypothesized model comprising 48 items across 4 factors- knowledge, attitude, behavior, and training ((χ2)387.38, p-value = 0.000, CFI = 0.816, and RMSEA = 0.081). The model was readjusted by excluding three attitude items having low factor loadings (<0.4). The final refitted CFA model of 45 items showed satisfactory goodness of fit indices. These factors were identified as 1) level of knowledge of nutrigenomics (16 items), 2) attitude and willingness to adopt personalized nutrition (18 items), 3) behaviors related to applications of nutrigenomics in disease management (7 items), and 4) training and confidence to practice PN (4 items). Table 2 represents the results of CFA analysis with their associated factor loadings and fit indices of Comparative Fit Index (CFI), Tucker Lewis Fit Index (TLI), and Root Mean Square Error of Approximation (RMSEA) measure values (Table 2). The results of our study showed acceptable construct validity across the four domains of the questionnaire. INSERT TABLE 2.
Internal Consistency and test-retest reliability – The mean Cronbach alpha coefficient was 0.82, indicating acceptable to excellent internal consistency of the questionnaire. All items within the four factors in the questionnaire had acceptable to excellent internal consistency (α > 0.76). To test the reliability, a sub-sample (n=64, 95.3% women, 75.0% between 18-25 years, 37.5% with graduate degrees in nutrition, and 17.2% having > 10 years of experience) completed the questionnaire twice with a mean duration of 17.3 (3.2) days between first and second administration of the KAB-PN. The intraclass correlation coefficients for knowledge, attitude, behavior, and training domains were 0.74 (95% CI 0.57-0.84), 0.83 (95% CI 0.71- 0.90), 0.72 (95% CI 0.63- 0.87), and 0.81 (95% CI 0.69-0.89), respectively, indicating good to excellent reliability. Table 3 shows the results of the internal consistency and test-retest reliability. INSERT Table 3.
Results of cross-sectional data analysis for KAB related to nutrigenomics and PN
Overall, the knowledge regarding the basics of genetics such as genes, polymerase chain reaction, chromosomes, transcription, genotype, and phenotype was reported as adequate. However, the awareness regarding epigenetic modifications, omics techniques, histone modifications, SNPs and DNA methylation, the difference between the terms- nutrigenomics vs nutrigenetics, and names of genetic variants associated with obesity and caffeine metabolism was inadequate. The majority (83.2%) mentioned that PN should be a critical component of customized diet counseling, 77.2% agreed that nutrigenomics merits inclusion in the nutrition curriculum in universities, and 35.8% showed concerns regarding ethics in genetic testing. Around 43.8% agreed that the patients’ adherence to dietary recommendations may improve with the application of genotype-based PN in dietetic practice, though 63.6% mentioned that the medical fraternity is still not ready to transition to genetic profile-led nutritional care unless evidence-based and explicit practice guidelines are drafted and implemented (Table 5). Two-thirds (68%) showed a willingness to update themselves regarding nutrigenomics, 79.8% were not confident to discuss the pros and cons of personalized nutrition with clients, and 59% mentioned that they may consider collecting genetic information as part of a family or disease history (Table 6).
INSERT TABLE 5 and TABLE 6.