DMX is handling his legal business and his diet like a grown ass man after going to rehab.

We got X Thursday outside court in NYC, where he had a hearing on his tax evasion case. Afterward, he basically confirmed what his lawyer told us last month -- he put on about 40 lbs. while getting treatment, and plans to continue for another month.

Gotta say, he looks good compared to a couple months ago when he was significantly thinner. Sounds like he feels the same way.

As for what he's bulking up on? DMX trusts in the Cap'n!

X GON' GIVE YA A HOT DOG
TMZ.com