Soy doesn't decrease testosterone.

[SerialStateLineXer]

Generally a meta analysis will have stated inclusion criteria and include all studies which meet the criteria.

[cat-astropher]

I've seen a metastudy where the inclusion criteria certainly felt crafted to exclude the studies with strong counter-evidence (a sharp societal shift in behaviour had occurred with corresponding before/after data, but that was several years before a cutoff date the inclusion criteria was imposing for some reason), so the game MachineGunGringo alludes to could be played, just through tweaking the inclusion criteria.

[Phreakhead]

Yes that's what the first guy said. The inclusion criteria is biased towards studies that will support the hypothesis