05/17/2012 at 04:45 PM EDT
is perfectly happy not being one of those super-skinny celebrity types. In fact, she says, when she sees them, her stomach growls.
"Really skinny actresses make me hungry," the country star tells Self
in its June issue. "I see them and think, 'Honey, you need to eat!' I'm lucky I don't have to live like that."
Lambert, 28, who married fellow country star Blake Shelton
in May 2011, says she's pretty comfortable with her body.
"I don't mind having a big butt," she says. "I actually like that about myself."
Still, the singer
tries to stay fit – and maintain a certain weight. "I feel my best when I'm a toned, not flabby, size 8," she says in the interview. "I'm a confident person overall. Though like any other girl, I have insecurities."
"But my job is to entertain," she continues. "I can't call in insecure and miss a show."
Occasionally – say, over the holidays, for instance – Lambert
says she'll gain a few pounds. And she's fine with that – temporarily.
"It's okay to be fat and lazy sometimes," she says. "But eventually you're like, 'Oh crap, I shouldn't have done that!' "
Instead, she's focusing on eating healthier.
"I always scarf down food after a show," she says. "But now, instead of eating a burger, I'll have a grilled chicken salad waiting for me. And except for almonds and bananas, I don't keep snacks on the bus. I don't want Cheetos anywhere around me!"