A rapid review of meta-analyses and systematic reviews of environmental footprints of food commodities and diets

Systematic reviews, sometimes including meta-analyses, are often presented as an approach for identifying healthy and sustainable diets. Here we explore to which extent systematic review protocols have been adopted by studies comparing environmental impacts of foods based on Life Cycle Assessment (LCA) results, they comply with the PRISMA protocol transparent reporting. Out 224 screened, seven explicitly define themselves and/or claim carry out meta-analyses. Of these, only one acknowledges a protocol, while none complies all criteria. Neither do believe that reviews LCA results can criteria or due underreporting standard deviations artificial sample sizes in LCAs. Nonetheless, food commodities diets would benefit from better aligning protocols. • No dietary footprints protocol. The current carrying reporting incompatible Methodological bias largely overlooked among footprint studies.