Perspective: The Evidence-Based Framework in Nutrition and Dietetics: Implementation, Challenges, and Future Directions

Olive Oil Consumption, Risk Factors, and Diseases: An Umbrella Review

CONTEXT

Olive oil is a vegetable oil that provides health benefits, including a reduction in free radicals and total cholesterol and prevention of chronic diseases. The escalating incidence of chronic diseases presents a substantial challenge to public health, prompting numerous studies to assess these health-related effects. Despite several systematic reviews and meta-analyses summarizing the association between olive oil consumption and specific health outcomes, there is no summary of the accumulated evidence from these reviews.

OBJECTIVE

This umbrella review summarizes the evidence on olive oil consumption or intervention in adults and its association with multiple risk factors and diseases.

DATA SOURCES

We retrieved systematic reviews of randomized trials or observational studies on oral interventions or the consumption of olive oil. The systematic search encompassed databases including MEDLINE, Embase, Scopus, Web of Science, LILACS, and CENTRAL from inception to February 6, 2023.

DATA EXTRACTION

Two independent reviewers conducted data extraction and assessed methodological quality using the Joanna Briggs Institute tool.

DATA ANALYSIS

Overall, 17 systematic reviews of randomized trials and observational studies, covering outcomes such as cardiovascular diseases, cancer, type 2 diabetes, glucose metabolism, inflammatory and oxidative markers, and all-cause mortality, were included. The evidence suggests a beneficial association between olive oil consumption and cardiovascular diseases, cancer, type 2 diabetes, and all-cause mortality. However, the evidence was less definitive for inflammatory markers, oxidative stress, glucose metabolism, and blood lipid outcomes. Several meta-analyses revealed high heterogeneity and wide confidence intervals, along with a limited number of randomized clinical trials.

CONCLUSION

Given the high heterogeneity and low quality of evidence, further studies involving randomized trials are imperative. Prioritizing an in-depth analysis of specific olive oil components and using a control group with distinct characteristics and different effects is strongly recommended.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022357290.

Nature of the evidence base and approaches to guide nutrition interventions for individuals: a position paper from the Academy of Nutrition Sciences

This Position Paper from the Academy of Nutrition Sciences is the third in a series which describe the nature of the scientific evidence and frameworks that underpin nutrition recommendations for health. This paper focuses on evidence which guides the application of dietary recommendations for individuals. In some situations, modified nutrient intake becomes essential to prevent deficiency, optimise development and health, or manage symptoms and disease progression. Disease and its treatment can also affect taste, appetite and ability to access and prepare foods, with associated financial impacts. Therefore, the practice of nutrition and dietetics must integrate and apply the sciences of food, nutrition, biology, physiology, behaviour, management, communication and society to achieve and maintain human health. Thus, there is huge complexity in delivering evidence-based nutrition interventions to individuals. This paper examines available frameworks for appraising the quality and certainty of nutrition research evidence, the development nutrition practice guidelines to support evidence implementation in practice and the influence of other sources of nutrition information and misinformation. The paper also considers major challenges in applying research evidence to an individual and suggests consensus recommendations to begin to address these challenges in the future. Our recommendations target three groups; those who deliver nutrition interventions to individuals, those funding, commissioning or undertaking research aimed at delivering evidence-based nutrition practice, and those disseminating nutritional information to individuals.

Dietary Provision, GLIM-Defined Malnutrition and Their Association with Clinical Outcome: Results from the First Decade of nutritionDay in China

Malnutrition is a common and serious issue that worsens patient outcomes. The effects of dietary provision on the clinical outcomes of patients of different nutritional status needs to be verified. This study aimed to identify dietary provision in patients with eaten quantities of meal consumption and investigate the effects of dietary provision and different nutritional statuses defined by the GLIM criteria on clinical outcomes based on data from the nutritionDay surveys in China. A total of 5821 adult in-patients from 2010 to 2020 were included in this study's descriptive and Cox regression analyses. Rehabilitation and home discharge of 30-day outcomes were considered a good outcome. The prevalence of malnutrition defined by the GLIM criteria was 22.8%. On nutritionDay, 51.8% of all patients received dietary provisions, including hospital food and a special diet. In multivariable models adjusting for other variables, the patients receiving dietary provision had a nearly 1.5 higher chance of a good 30-day outcome than those who did not. Malnourished patients receiving dietary provision had a 1.58 (95% CI [1.36-1.83], p < 0.001) higher chance of having a good 30-day outcome and had a shortened length of hospital stay after nutritionDay (median: 7 days, 95% CI [6-8]) compared to those not receiving dietary provision (median: 11 days, 95% CI [10-13]). These results highlight the potential impacts of the dietary provision and nutritional status of in-patients on follow-up outcomes and provide knowledge on implementing targeted nutrition care.

Critically appraising and utilising qualitative health research evidence in nutrition practice

BACKGROUND

Evidence-based decision-making and practice recommendations are commonly based on findings from quantitative studies or reviews. In the present study, we provide an overview of how to incorporate findings from qualitative research into the evidence-based decision-making process.

METHODS

To illustrate how qualitative evidence can be integrated into the decision-making process, we have outlined a clinical nutrition scenario and the process for sourcing credible evidence to inform decision-making. A qualitative health research study was selected and appraised using the Critical Appraisal Skill Programme (CASP) appraisal tool for qualitative research. Based on the results of the critical appraisal, the study quality is considered, and we discuss whether the qualitative evidence can be applied to practice.

RESULTS

A detailed description of how the qualitative findings can be used conceptually and instrumentally in practice to address the clinical nutrition scenario is provided.

CONCLUSIONS

Developing skills in critically appraising findings from qualitative studies will increase awareness and utilisation of this type of evidence in practice and policy, with a goal to ensure that patient/client perceptions are considered, leading to enhanced person-centred care or systems.

Use of #NutritionFacts to promote evidence-based nutrition information: X (formerly Twitter) hashtag analysis study

Nutrition is a key determinant of health, and the dissemination of reliable nutrition information to consumers is of great importance for public health. Especially with the rise of digital communication technologies and the wide-spread online misinformation, the provision of qualitative science-based information related to diet is of great importance. The NutritionFacts.org has been established as a prominent online source of evidence-based nutrition information. In this work we aimed to investigate the use of the associated hashtag #NutritionFacts on X (formerly Twitter) over a 5 years period, from 10th of April 2018 to 10th of April 2023. The conducted analysis with the use of Symplur Signals revealed that 18,998 tweets mentioning #NutritionFacts were posted by 6,136 X users, generating a total of 50,348,223 impressions (views). Both institutional and individual accounts were broadly participating in the dissemination of #NutritionFacts tweets, and the user location profiling indicated wide international engagement with the hashtag. This work indicates that #NutritionFacts has been established as an important hashtag utilized on X for the dissemination of evidence-based information related to nutrition.

Novel Lines of Research on the Environmental and Human Health Impacts of Nut Consumption

Nuts have formed part of human diets throughout the ages. In recent decades, research has shown they are key foods in dietary patterns associated with lower chronic disease risk. The current state of climate change, however, has introduced an imperative to review the impact of dietary patterns on the environment with a shift to plant-based diets. Nuts emerge as a significant source of protein in plant-based diets and are a minimally processed and sustainable food. Research in this area is evolving to drive better production methods in varying climate conditions. Nevertheless, nut consumption remains an important contributor to human health. The mechanisms of action can be explained in terms of the nutrients they deliver. Studies of nut consumption have linked components such as monounsaturated fatty acids, plant omega-3 fatty acids, antioxidants, and plant sterols to improved lipoprotein profiles, lower blood pressure, and reduced cardiovascular disease risk. Preliminary research also indicates possible beneficial effects of nut consumption on reproductive health. In any case, the ultimate effects of foods on health are the results of multiple interactive factors, so where nuts fit within dietary patterns is a significant consideration for research translation. This has implications for research methodologies, including categorization within food groups and inclusion in Healthy Dietary Indices. The aim of this narrative review is to outline new focal points for investigation that examine the environmental and some novel human health impacts of nut consumption and discuss future directions for research.

The use and acceptability of diet-related apps and websites in Australia: Cross-sectional study

Objective

Diet-related apps and websites are developed to help improve dietary intake. The aim of this study is to explore the use and acceptability of diet-related apps and websites in Australia.

Methods

In a cross-sectional study, 241 participants (mean age = 40.6 years) completed an online survey about demographic characteristics, lifestyle behaviours and health concerns, experience and confidence in technology use, and preferences, attitudes and perception of diet app and website use. Descriptive analysis and unadjusted multiple logistic regression were used to explore data.

Results

Overall, 63.5% of participants were current or previous app users. App users were more confident in using technology, more concerned about diet and weight, and more trusting of information provided in diet-related apps compared to non-app users (p ≤ .05). Features such as food tracking, nutrient check and barcode scanning were preferred by both users and non-users. The likelihood of using diet-related apps was higher for those who trust the app information (OR 5.51, 95%CI: 2.40-12.66), often count calories (OR 2.28, 95%CI: 1.01-5.24) and are often on diet (OR 4.16, 95% CI: 1.21-14.21) compared to their counterparts.

Conclusions

More than half of the Australians that participated in this study used diet-related apps and websites. App features that allow the user to accurately record and monitor food intake and scan barcodes may motivate app use. Future public health strategies may take advantage of diet-related apps and websites to improve dietary behaviour at the population level and reduce the burden of obesity and non-communicable diseases.

Nature of the evidence base and strengths, challenges and recommendations in the area of nutrition and health claims: a position paper from the Academy of Nutrition Sciences

The regulation of health claims for foods by the Nutrition and Health Claims Regulation is intended, primarily, to protect consumers from unscrupulous claims by ensuring claims are accurate and substantiated with high quality scientific evidence. In this position paper, the Academy of Nutrition Sciences uniquely recognises the strengths of the transparent, rigorous scientific assessment by independent scientists of the evidence underpinning claims in Europe, an approach now independently adopted in UK. Further strengths are the separation of risk assessment from risk management, and the extensive guidance for those submitting claims. Nevertheless, four main challenges in assessing the scientific evidence and context remain: (i) defining a healthy population, (ii) undertaking efficacy trials for foods, (iii) developing clearly defined biomarkers for some trial outcomes and (iv) ensuring the composition of a food bearing a health claim is consistent with generally accepted nutrition principles. Although the Regulation aims to protect the consumer from harm, we identify some challenges from consumer research: (i) making the wording of some health claims more easily understood and (ii) understanding the implications of the misperceptions around products bearing nutrition or health claims. Recommendations are made to overcome these challenges. Further, the Academy recommends that a dialogue is developed with the relevant national bodies about Article 12(c) in the Regulation. This should further clarify the GB Guidance to avoid the current non-level playing field between health professionals and untrained ‘influencers’ who are not covered by this Article about the communication of authorised claims within commercial communications.

Nutrition and Health Claims: Consumer Use and Evolving Regulation

Purpose of Review

The value of nutrition and health claims (N&HC) depends on how consumers use them and the regulatory framework that enables them. This paper aims to explore the impact of claims on consumer behaviour and identify evolving regulatory challenges, using the Australian experience as a reference point.

Recent Findings

N&HC can influence consumer food purchasing and consumption, but how consumers interpret and act on specific claims is less well understood, and regulatory frameworks are evolving. In the last 10 years, changes to the Australian regulatory framework have exposed greater opportunities for promoting foods, albeit with challenges regarding self-substantiation of claims.

Summary

N&HC can play a significant role in driving consumer choices towards a healthier food supply. The Australian experience demonstrates how N&HC can continue to evolve, reflecting developments in methodologies and a fundamental appreciation of the relationship between food and health.

Undertaking a research project improves confidence in research skills among student dietitians

BACKGROUND

Research is a cornerstone of evidence-based dietetic practice. Research skills are often taught at university through experiential learning during a final-year research project. The aim of this study was to investigate attitudes towards research and confidence in research skills among student dietitians before and after a research project.

METHODS

A questionnaire survey of student dietitians' attitudes to research and confidence in research skills was undertaken before and after completing a research project at two universities in London, United Kingdom. Dichotomous data were compared before and after the research project using a McNemar's test. Factors associated with 'high confidence' or 'improved confidence' in overall research skills at the end of the research project were investigated using multivariable logistic regression.

RESULTS

160 student dietitians completed a questionnaire before and after their research project. The majority had positive attitudes to research both before and after their research project. There was an increase in numbers with 'high confidence' in overall research skills before (13, 8.1%) and after (79, 49.4%) the research project (P<0.001), and 113 (70.6%) reported 'improved confidence' in overall research skills. The only factor associated with 'high confidence' in overall research skills was having 'high levels of involvement in the overall research process' (OR 6.13, 95% CI 2.03-18.49, P=0.001).

CONCLUSIONS

Student dietitians have positive attitudes towards research and undertaking a research project significantly improves confidence in their research skills. Higher level of involvement in the research project is the single most significant factor associated with high confidence in research skills. This article is protected by copyright. All rights reserved.

Governing evidence use in the nutrition policy process: evidence and lessons from the 2020 Canada food guide

Nutrition guideline development is traditionally seen as a mechanism by which evidence is used to inform policy decisions. However, applying evidence in policy is a decidedly complex and politically embedded process, with no single universally agreed-upon body of evidence on which to base decisions, and multiple social concerns to address. Rather than simply calling for “evidence-based policy,” an alternative is to look at the governing features of the evidence use system and reflect on what constitutes improved evidence use from a range of explicitly identified normative concerns. This study evaluated the use of evidence within the Canada Food Guide policy process by applying concepts of the “good governance of evidence” – an approach that incorporates multiple normative principles of scientific and democratic best practice to consider the structure and functioning of evidence advisory systems. The findings indicated that institutionalizing a process for evidence use grounded in democratic and scientific principles can improve evidence use in nutrition policy making.

The essentiality of nutrients: a challenge to methodological monism in the scientific substantiation of health claims

This paper analyzes the way in which the EFSA has addressed the limitations that the essentiality of nutrients presents to the requirement of obtaining evidence from RCTs for the scientific substantiation of health claims. By redefining the requirements to affirm causality in the case of essentiality of nutrients, the EFSA has constrained the debate on the relevance of different methodologies in the field of nutrition research. However, avoiding this methodological debate does not settle the controversy as to whether the EFSA's evidentiary hierarchy is the best for both investigating causal relationships in nutrition and for achieving social objectives such as fostering innovation and public health.

Implementation science for dietitians: The 'what, why and how' using multiple case studies

AIM

Implementation science theories, models and frameworks help to address evidence-practice gaps, which have increasing importance for dietetic practice. This paper aims to provide dietitians with insight into how implementation science can be applied to practice, using multiple 'real-life' case studies.

METHODS

Three case studies were purposively selected across areas of dietetics practice to demonstrate application of commonly-used implementation theories, models and frameworks. Reflections from the authors were provided in response to a structured set of questions outlining how the theoretical approach was selected and used, and considerations for future application. Within and cross-case analysis was undertaken.

RESULTS

Dietitians used diverse implementation theories, models and frameworks to identify barriers and enablers, to plan for implementation, and to guide the selection of implementation strategies. Implementation theory was used to evaluate the implementation process in one case study. Cross-case analysis identified that mentoring by those with implementation expertise, multidisciplinary implementation teams, and leadership and investment in research and translation at an organisational and departmental level as key enablers.

CONCLUSIONS

This paper offers dietitians insight into how implementation science can be applied to improve the uptake of evidence-based practices within nutrition and dietetics, and suggests that there needs to be investment in implementation science as a foundation science within nutrition and dietetics, including education, training and mentoring for dietitians.

Perspective: Modeling Healthy Eating Patterns for Food-Based Dietary Guidelines-Scientific Concepts, Methodological Processes, Limitations, and Lessons

The relations between dietary features and human health are varied and complex. Health-related variables are many and they have intricate relations at different and interrelated nutritional levels: nutrients, food groups, and the complex overall pattern. Food-based dietary guidelines (FBDGs) are principally designed to synthesize this information to make it available to the public. Here, we describe the method used to establish healthy eating patterns (HEPs) for the latest French FBDGs, which consists of in-depth food pattern modeling using an enhanced optimization method that gathered all aspects of HEPs. We present the novelty of this food modeling approach for FBDGs, which aims to gather information related to nutrients, food contaminants, and epidemiological relations with long-term health, and to be combined with the objective of realistic dietary patterns that deviate minimally from the prevailing diet. We draw lessons from stepwise implementation of the method and discuss its strengths, limitations, and perspectives. In light of the modeled HEPs, we discuss the importance of food grouping; of accounting for dietary habits while not precluding modeled diets that can be realistic/acceptable; and of taking into account the exposure to food contaminants. We discuss the tolerance and flexibility to be applied to certain dietary reference values for nutrients and health-based guidance values for contaminants so that HEPs can ultimately be identified, and how account can be taken of varied health-related outcomes applied to food groups. Although the approach involves all the peculiar uncertainties of numerous optimization model parameters and input data, its merit is that it offers a rationalized approach to establishing HEPs with multiple constraints and competing objectives. It is also versatile because it is possible to operationalize further dimensions of dietary patterns to favor human and planetary health.

Is a Healthy Diet Also Suitable for the Prevention of Fragility Fractures?

Osteoporosis and sarcopenia contribute to the risk of fracture in the population. These conditions share common features, and it is known that a healthy diet may have beneficial effects on both, theoretically resulting in fewer fractures. The present narrative review gives an overview of recent epidemiological research related to the association between healthy diets/dietary patterns, bone health and fragility fractures. The review also gives a brief overview on general dietary recommendations and advice as the cornerstone of public health nutrition. Although muscle health and sarcopenia contribute to the risk of fractures, these endpoints were not the focus of this review. Healthy diets are nutrient dense and contain bioactive components that are needed for the constant remodeling of the skeleton and to slow the rate of bone loss and muscle wasting, thus contributing to the prevention of fragility fractures. Compliance with healthy dietary patterns were predominantly found to be inversely associated with bone outcomes, although this was not entirely consistent across all studies. Different a priori diet scores, such as the Mediterranean diet score and the Dietary Inflammatory Index, as well as a posteriori data driven dietary patterns, such as the prudent or healthy dietary pattern, were inversely associated with fragility fractures in different populations. In conclusion, different healthy dietary patterns may contribute to bone health and less fractures. Following current dietary guidelines is thus advisable for the prevention of fragility fractures.

Examining the Role of Anxiety and Depression in Dietary Choices among College Students

This study examines the role of anxiety and depression symptoms in predicting dietary choices in emerging adults while accounting for sex differences in these relationships. Participants were 225 English speaking undergraduates enrolled in a university in southeastern United States. Participants were recruited through an online research recruitment application utilized by the university. Participants volunteered for a two-phased anonymous survey monitoring the effects of eating habits and gastrointestinal health in young adults. As part of this effort, participants completed self-reporting measures related to anxiety and depression, as well as an automated, self-administered 24-h diet recall. Multigroup path analysis was used to test primary hypotheses. Overall, a decrease in total caloric intake and an increase in sugar consumption were found as self-reported symptoms of anxiety and depression increased. In addition, there were sex differences in the relationship between depression and food choices. Men consumed more saturated fat as well as less fruits and vegetables as self-reported symptoms of depression increased. Results suggest symptoms of depression are a greater risk factor for poor nutrition in male college students than females. The findings provide another justification to screen for psychological distress in student health services given the implications on behavioral lifestyle and health.

Overweight and obesity of school-age children in El Salvador according to two international systems: a population-based multilevel and spatial analysis

BACKGROUND

The World Health Organization (WHO-2007) and the International Obesity Task Force (IOTF-Cole) systems assess child weight status. However, derived estimations often differ. We aimed to a) compare the prevalence of overweight and obesity, b) analyze individual and contextual factors associated with child weight using multilevel analysis and c) explore the spatial distribution of overweight and obesity using both classification systems.

METHODS

We used data from the 2015/2016 National School Height and Weight Census in El Salvador. Information on 111,991 children aged 6.0-9.9 years attending the first grade was analyzed. Body mass index Z-score (BMIZ), overweight and obesity were defined with both classification systems. Weighted kappa was used to measure agreement. Child, school and municipal potential determinants of BMIZ were examined by multilevel analysis. Municipal spatial clustering of overweight and obesity was tested using Moran's Index and Getis-ord Gi* statistics.

RESULTS

The combined prevalence of overweight and obesity was higher according to the WHO system than the IOTF (30.4% vs 23.1%). The weighted kappa was 0.83. Boys, children attending urban schools, children attending private schools, and children residing in municipalities with high human development index had higher BMIZ than their counterparts. The Moran's indexes were positives and significant. Clusters of high prevalence (above the national prevalence) of overweight and obesity were found in 29 municipalities using the WHO and IOTF systems. For obesity, 28 and 23 municipalities in clusters of high prevalence were detected using the WHO and IOTF criteria, respectively.

CONCLUSIONS

Overweight and obesity is high among school-age children in El Salvador. The prevalence of overweight and obesity was higher when using the WHO system, as compared to the IOTF system. Irrespective of the classification system, the multilevel and spatial analysis derived similar interpretations. These results support the need for national preventive interventions with targeting strategies to reduce overweight and obesity in school-age children.

Knowledge Translation in Dietetics: A Survey of Dietitians' Awareness and Confidence

This study aimed to determine dietitians' familiarity with knowledge translation (KT), confidence in undertaking KT, and preferences for receiving KT training. An online questionnaire was designed and disseminated to all dietitians working across hospital and health services in Queensland, Australia, for completion over a 6-week period (April-May 2018). Of the 124 respondents, 69% (n = 85) reported being familiar with KT, but only 28% (n = 35) reported being confident in applying KT to their practice. Higher confidence was reported with problem identification, evidence appraisal, and adapting evidence to local context, compared with implementation, evaluation, and dissemination. Almost all respondents reported an interest in learning more about KT (n = 121, 98%), with a preference for easily accessible and short "snippets" of training aimed at beginner-intermediate level. Lack of management support, difficulty attending multi-day courses, cost, travel requirements, and lack of quarantined time were reported barriers to attending KT training. There is a high awareness and interest but low confidence in undertaking KT amongst dietitians. This highlights an opportunity for workforce development to prepare dietitians to be skilled and confident in KT. Training and support needs to be low-cost and multi-modal to meet diverse needs.

Exploring perceptions, barriers and use of systematic reviews amongst nutrition professionals and nutrition students

AIM

Systematic reviews (SRs) are a core component of evidence-based practice and are widely used in developing nutrition policy. This study aimed to examine nutrition professionals and students' perceptions, barriers and use of SRs. A secondary aim was to examine confidence using and conducting SRs.

METHODS

A self-administered online survey was developed, pilot-tested and implemented via SurveyMonkey. The survey consisted of 29 items separated into demographics, perceptions, use, and knowledge of SRs, confidence in using and conducting SRs, and barriers to use and conduct of SRs. The survey was disseminated via professional newsletters and social media.

RESULTS

Ninety-four nutrition professionals/students completed the survey. Survey results indicated respondents valued SRs, with SRs used most commonly to update knowledge. While most respondents (67%) were confident in using SRs, many (59%) expressed a lack of confidence in conducting a SR. In particular, few respondents (12%) reported confidence in conducting meta-analyses. The majority of respondents were aware that SRs underpinned guidelines and nutrition resources, however, few (21%) respondents identified that self-substantiation of health claims were based on SRs. Time, access to scientific database, lack of workplace support and confidence were the main barriers to SRs use.

CONCLUSIONS

SRs were reported as being valued by nutrition professionals and students, though time constraints, a lack of confidence and organisations which did not prioritise research were barriers to conducting SRs. The findings of this survey highlight a need for training and education as potential strategies to promote SR engagement in nutrition professionals and students.