"I just really wanted to be comfortable for the interview," Gaga explained to Kimmel.
The performer's consumption of Austin's renowned barbecue could also be to blame. Gaga jokingly added later, "That's why I wore it, because I'm really fat right now."
The "Applause" singer also discussed her love for live music (her provocative SXSW performance later Thursday night featured a "vomit painter"). Gaga said what she misses most about her pre-fame days is being able to go to concerts without being noticed.
Perhaps, a costume change could help.
See more of Kimmel's interview with Lady Gaga below.