Experts Push for GRADE Methodology to Transform Nutrition Guidelines

In a significant move towards improving nutrition guidance, Bradley C. Johnston and his team at EvidenceBasedNutrition.org are advocating for the adoption of the GRADE methodology. This initiative aims to ensure that nutrition evidence is consistently evaluated and applied in both clinical and public health settings. Their recent advocacy highlights the pressing need for standardized approaches to assessing research quality, an issue that affects healthcare providers, patients, and the general public seeking reliable dietary guidance.

The nutrition field often suffers from shifting advice that can lead to confusion. Johnston points out that this inconsistency stems from a failure to clarify the certainty of evidence and the strength of recommendations. A notable example is the shift in dietary guidelines regarding fat intake, which changed from a cap of 20% to 35% of daily calories in the United States from the 1960s until 2015. Initially, these guidelines did not distinguish between saturated and unsaturated fats, leading to widespread confusion and the development of numerous low-fat products that often replaced fats with refined carbohydrates.

A systematic review conducted by Johnston and his colleagues, published in The Journal of Nutrition, found a lack of studies focusing on dietitians’ competencies in interpreting the magnitude of health outcomes and the certainty of evidence. This gap is concerning, especially given that strong evidence-based practice (EBP) competencies are linked to more stable dietary advice and improved patient outcomes. The review analyzed 12 studies from six countries and revealed a troubling trend: no studies reported on competencies related to assessing effect size or evidence certainty, and many relied on self-perceived assessments rather than objective measures.

Implementing GRADE as a Standard

Johnston is a strong proponent of training healthcare professionals and students in evidence-based practice, particularly through the use of GRADE methodology. This approach, endorsed by over a hundred organizations globally—including the American Academy of Nutrition and Dietetics and the World Health Organization—provides a structured framework for evaluating the certainty of evidence and formulating recommendations.

The rationale behind using GRADE is clear. Johnston explains that to effectively compare various dietary interventions, physical activity strategies, and medications for reducing cardiovascular risk, it is essential to use a consistent standard. Without this framework, comparisons become ineffective and can mislead decision-making processes. Recently, Johnston collaborated with over 50 interdisciplinary professionals to apply GRADE methods in creating evidence-based guidelines for managing pediatric obesity, incorporating strategies like semaglutide and bariatric surgery.

Nutrition research presents unique challenges that necessitate careful consideration within the GRADE framework. Many nutrition questions lack robust randomized controlled trials (RCTs), and those that exist often do not have true placebos. Additionally, adherence to dietary intervention RCTs can be problematic, and the duration may not capture long-term health impacts. When RCTs are of low quality or unavailable, recommendations often rely on observational studies, which typically start with low certainty under GRADE methods. Johnston and his colleagues argue that GRADE can adapt to these challenges while maintaining rigorous scientific standards.

Advancing Educational Initiatives

Johnston’s efforts extend beyond identifying problems; he also contributes to developing solutions. The Nutrition Users’ Guides represent a collaborative effort among experts to provide structured guidance for evaluating nutrition literature. Each article in this series addresses key components, including assessing methodological quality, interpreting study results, and applying findings to specific patient scenarios.

Johnston emphasizes the importance of transparency in literature reviews and guidelines. He believes that when GRADE methods are applied correctly, they can enhance the clarity and reliability of evidence assessments. This transparency allows others in the field to understand the rationale behind conclusions, fostering open discussions about the strengths and weaknesses of dietary recommendations.

While the systematic review did not evaluate training among nutrition professionals, Johnston advocates for standardized EBP training in the nutrition field. He notes that current training requirements vary significantly across countries and institutions, resulting in inconsistencies in how competencies are taught. Establishing standardized training would uplift the profession, enabling registered dietitians to lead among allied health professionals and enhance communication with clients.

Through these initiatives, Johnston and his colleagues are committed to transforming how nutrition professionals interact with research evidence. Their work aims to empower health service workers and policymakers to better understand and apply nutrition literature, facilitating informed, evidence-based decisions among practitioners and their clients.