Meta-analyses citing non-randomized intervention studies, particularly in pharmaceuticals, may show similar findings to randomized studies, but this does not necessarily apply to nutrition epidemiology.

“if you look at these meta-analyses it looks like non-randomized studies on average give very similar findings to randomized studies but often they're citing non-randomized intervention studies not non-randomized observational studies and they're often not citing nutrition studies they're citing pharmaceutical or other medical treatment so those are very different situations”