Well, I'm glad he's behaving better. The thing is, alcoholism is progressive, so until/unless he is ready to quit drinking for GOOD, and to do the hard work it takes to get there, it won't last.
It's not just a matter of adopting a "healthy lifestyle"--that's a RESULT of sobriety, but alcoholism is a much more complicated thing than that.
Not out to bring you down, just to give you a dose of reality so you don't feel horribly hurt when it all goes south. I hope you're doing some reading up on alcoholism.