Engaged Carrie Underwood stays super slim by avoiding fast food on the road -- but it's not easy.
"I think the hardest thing about what I do is eating [healthy] because we're all over the place," the singer, 27, told UsMagazine.com at Wednesday's Idol Gives Back.
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"It's fast food, there's aftershow food, you get pizza, whatever," continued Underwood, who recently revealed she and fiance Mike Fisher set a wedding date (but wouldn't say when!). "I don't do that. I don't eat out ever."
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"Every once in a while I have a day off and I might go to a restaurant -- but no aftershow food and I keep my fridge stocked," she added.
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She also makes "a point to get up and work out" before hitting the stage.
"It's all about making a conscious effort. I don't do anything crazy, but I definitely try to take care of myself," she told Us.