GIMP's download setup is a bit odd. Their direct, main download page is here.
Note that their biggest link is a torrent download. That doesn't mean it's illegal somehow or automatically untrustworthy, that's just the one they make the biggest target.
But notice under that, it states:
If the torrent download doesn't work, you can also follow this link.
The words "this link" directly downloads a standard Mac .dmg installer. That's the one I would use. If for no other reason it doesn't require having torrent software to download it. Not sure why that isn't their main method to start with.