NFL's Arthur Jones: I Lost 25 lbs In 3 Wks ... Here's How

Arthur Jones is lean, mean and ready for an NFL return after shedding 25 freakin' pounds in 3 weeks ... and he's telling TMZ Sports how he got it done.

Arthur -- Jon Jones' older bro -- is a 6-year NFL vet who's currently a free agent ... but that hasn't stopped him from stayin' in game shape.

Matter of fact -- better than game shape.

Jones -- who recently had hernia surgery -- decided to switch up his eating and workout habits shortly after the procedure ... swearing off all animal products and hittin' the yoga studio.

A.J. even gives us his ideal NFL landing spots ... and spoiler alert, one team already has a Jones on the D-line.