Exploring Attitudes, Subjective Norms and Perceived Behavioural Control in a Genetic-Based and a Population-Based Weight Management Intervention: A One-Year Randomized Controlled Trial

Health Belief and Behavioral Analysis of Fad Diets: A Perspective from Younger Generations in a Developing Country

The surge in popularity of fad diets has raised concerns about compromised health among individuals due to their beliefs and intentions regarding consumption. The aim of this study was to examine the prevalence of fad dieting among persons who are dieting and to determine the different factors influencing the inclination to adopt fad diets. Specifically, this study explored the ways in which individual openness to following fad diets, participation in diet trends, and characteristics may influence attitudes towards fad diet adoption. Data from 407 participants aged 18-34, collected via Google Forms, were analyzed using a high-ordered construct approach between the theory of planned behavior (TPB) and health belief model (HBM). Employing partial least squares structural equation modeling, significant results were obtained. The key findings revealed that knowledge about dieting, perceived benefits, and health motivation significantly influenced individuals' intentions to adopt fad diets. Additionally, the study demonstrated significant impacts of health motivation on attitude and perceived behavioral control, subsequently affecting individuals' intention to adopt dietary practices. Practical implications include the development of tailored health communication strategies for government agencies and informed decision-making support for individuals considering adopting fad diets. This research contributes valuable insights into the perception and psychological and social factors shaping dietary decisions, laying the groundwork for enhanced health education and intervention strategies. Furthermore, the study's theoretical framework offers potential for extension and application to health-related food consumption behaviors across diverse cultural contexts.

Assessment of the impact of a personalised nutrition intervention in impaired glucose regulation over 26 weeks: a randomised controlled trial

Dietary interventions can reduce progression to type 2 diabetes mellitus (T2DM) in people with non-diabetic hyperglycaemia. In this study we aimed to determine the impact of a DNA-personalised nutrition intervention in people with non-diabetic hyperglycaemia over 26 weeks. ASPIRE-DNA was a pilot study. Participants were randomised into three arms to receive either (i) Control arm: standard care (NICE guidelines) (n = 51), (ii) Intervention arm: DNA-personalised dietary advice (n = 50), or (iii) Exploratory arm: DNA-personalised dietary advice via a self-guided app and wearable device (n = 46). The primary outcome was the difference in fasting plasma glucose (FPG) between the Control and Intervention arms after 6 weeks. 180 people were recruited, of whom 148 people were randomised, mean age of 59 years (SD = 11), 69% of whom were female. There was no significant difference in the FPG change between the Control and Intervention arms at 6 weeks (- 0.13 mmol/L (95% CI [- 0.37, 0.11]), p = 0.29), however, we found that a DNA-personalised dietary intervention led to a significant reduction of FPG at 26 weeks in the Intervention arm when compared to standard care (- 0.019 (SD = 0.008), p = 0.01), as did the Exploratory arm (- 0.021 (SD = 0.008), p = 0.006). HbA1c at 26 weeks was significantly reduced in the Intervention arm when compared to standard care (- 0.038 (SD = 0.018), p = 0.04). There was some evidence suggesting prevention of progression to T2DM across the groups that received a DNA-based intervention (p = 0.06). Personalisation of dietary advice based on DNA did not result in glucose changes within the first 6 weeks but was associated with significant reduction of FPG and HbA1c at 26 weeks when compared to standard care. The DNA-based diet was effective regardless of intervention type, though results should be interpreted with caution due to the low sample size. These findings suggest that DNA-based dietary guidance is an effective intervention compared to standard care, but there is still a minimum timeframe of adherence to the intervention before changes in clinical outcomes become apparent.Trial Registration: www.clinicaltrials.gov.uk Ref: NCT03702465.

The Effect of Base Theory Educational Intervention on Health-Promoting Lifestyle in Women Susceptible to Cardiovascular Diseases: Application of the Theory of Planned Behavior

Background

Cardiovascular diseases are the second leading cause of mortality, disability, and reduced productivity in women over 40 years and the first cause of mortality in women over 60 years. Therefore, the present study aimed to determine the effect of educational intervention based on theory of planned behavior (TPB) on health-promoting lifestyle in women susceptible to cardiovascular diseases.

Methods

This quasiexperimental study was conducted on 200 women susceptible to cardiovascular diseases referred to health centers in Fasa city, Fars province, Iran. The available sampling was performed on women who referred to the centers and had a family record. In this study, two health-promoting lifestyle questionnaires consisting of 49 questions and the theory of planned behavior questionnaire consisting of 50 questions were used. The obtained data were analyzed by using the SPSS software version 24 in two stages before and six months after the educational intervention through paired t-test, independent t-test, chi-square test, and McNemar test.

Results

The mean age of women in the experimental and control groups was 38.74 ± 9.22 and 39.14 ± 9.08 years, respectively. The results showed a significant increase in the experimental group after six months of intervention in terms of health-promoting lifestyle and constructs of the theory of planned behavior. Also, mean blood pressure, fasting blood sugar, and smoking of experimental group decreased six months after the educational intervention.

Conclusion

Considering the irreplaceable role of education in adopting healthy behaviors and the role of women in strengthening the family foundation, quality educational programs should be designed and regularly implemented by health care providers for women.

Clinical Practice Guidelines Using GRADE and AGREE II for the Impact of Genetic Variants on Plasma Lipid/Lipoprotein/Apolipoprotein Responsiveness to Omega-3 Fatty Acids

Background

A recent systematic review, which used the GRADE methodology, concluded that there is strong evidence for two gene-diet associations related to omega-3 and plasma triglyceride (TG) responses. Systematic reviews can be used to inform the development of clinical practice guidelines (CPGs).

Objective

To provide guidance for clinical practice related to genetic testing for evaluating responsiveness to dietary/supplemental omega-3s and their impact on plasma lipids/lipoproteins/apolipoproteins.

Design

Using the results of the abovementioned systematic review, the first CPGs in nutrigenetics were developed using the established GRADE methodology and AGREE II approach.

Results

Three clinical practice recommendations were developed. Most gene-diet associations identified in the literature lack adequate scientific and clinical validity to warrant consideration for implementing in a practice setting. However, two gene-diet associations with strong evidence (GRADE quality: moderate and high) can be considered for implementation into clinical practice in certain cases: male APOE-E4 carriers (rs429358, rs7412) and TG changes in response to the omega-3 fatty acids eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) as well as a 31-SNP nutrigenetic risk score and TG changes in response to EPA+DHA among adults with overweight/obesity. Ethical and regulatory implications must be considered when providing APOE nutrigenetic tests given the well-established link between APOE genetic variation and Alzheimer's Disease.

Conclusion

Most of the evidence in this area is not ready for implementation into clinical practice primarily due to low scientific validity (low quality of evidence). However, the first CPGs in nutrigenetics have been developed for two nutrigenetic associations with strong scientific validity, related to dietary/supplemental omega-3 and TG responses.

Recent advances and current controversies in genetic testing for personalized nutrition

PURPOSE OF REVIEW

Considerable interest in personalized nutrition exists among the general public, policymakers, healthcare organizations and the private sector, but there is also skepticism of its utility. The present review aims to provide a summary of current controversies in the field of nutrigenomics, and to highlight recent research on the potential impact of implementing genetic testing for personalized nutrition in practice.

RECENT FINDINGS

Numerous companies already offer genetic testing for personalized nutrition based on research developments in nutritional genomics. However, controversy exists over whethexr genetics contributes to interindividual responses to diet; the utility of single genetic variants versus genetic risk scores; the ability of DNA-based nutritional advice to elicit positive behavior change and health effects; and whether genetic information makes a difference on the type of dietary advice provided. Potential factors contributing to the discrepant viewpoints are discussed.

SUMMARY

Despite the existing controversies, a solid body of evidence demonstrates that genetic testing for personalized nutrition is a powerful tool to guide dietary recommendations to improve health and performance, and to elicit positive behavior change.

Nutrition knowledge, food choices and diet quality of genotyped and non-genotyped individuals during the COVID-19 pandemic

BACKGROUND

Severe obesity (body mass index ≥ 40 kg/m²) and non-communicable diseases, both influenced by diet, have been associated with COVID-19. Genotype-based personalised nutrition advice may improve nutrition knowledge and enhance behaviour change towards better diet quality compared with conventional recommendations.

AIM

To investigate the nutrition knowledge, food choices and diet quality in genotyped and non-genotyped individuals during the COVID-19 pandemic.

METHODS

One hundred and twenty-three healthy UK adults were recruited using convenience sampling through social networks. The online questionnaire consisted of the General Nutrition Knowledge Questionnaire, the Food Choices Questionnaire, and the EPIC-Norfolk Food Frequency Questionnaire (FFQ). FFQ was used to calculate participant diet quality with the Diet Quality Index-International and socio-demographic and anthropometric data.

RESULTS

Median general nutrition knowledge, diet variety and diet balance scores were higher in genotyped compared with non-genotyped individuals (71.0 ± 11.0 vs. 61.0 ± 15.0, p = <.001, 18.00 ± 5.00 vs. 15.00 ± 5.00, p = .007 and 2.00 ± 4.00 vs. 0.00 ± 2.00, p = .025, respectively). Pooled sample multiple regression showed that health motive positively influenced while familiarity motive negatively influenced diet quality index scores (β = .428, t = 4.822, p = <.001 and β = -.356, t = -4.021, p = .001, respectively).

CONCLUSIONS

Nutrition knowledge and diet quality indices of balance and variety were higher among genotyped compared with non-genotyped individuals; overall diet quality was similar between groups. This may be due to pandemic-specific factors, such as altered motives of food choice and availability.