Where do expert opinion and background information fit in the hierarchy of evidence?

Expert opinion and background information are typically positioned at the bottom of the hierarchy of evidence because they represent less robust forms of evidence compared to other methodologies. The hierarchy of evidence is structured in a way that prioritizes evidence based on the rigor and reliability of the study design.

At the top of the pyramid, you find systematic reviews and meta-analyses of randomized controlled trials, which are considered the highest quality due to their comprehensive aggregation of data and critical analysis of multiple studies. In the middle levels, randomized controlled trials and cohort studies offer stronger evidence than expert opinions, as they utilize empirical data and a systematic approach to evaluating outcomes.

Expert opinions, while they can provide insight and context, are subjective and often based on personal experience or interpretation rather than systematic review. Thus, they are categorized at the bottom, reflecting their position as a less reliable source of evidence. This hierarchy emphasizes the importance of empirical research and systematic reviews in informing effective practices in sports nutrition and other fields.