But that doesn't mean she can't splurge a little -- especially during the holidays.
"I think because I am pregnant, I allow myself to eat things I normally don't eat," the country superstar tells ET in a new interview. "It's the holidays too, so it's just that time of year when you just want carbs. You're around your family and you're celebrating."
The country superstar, who announced in September that she and husband Mike Fisher are expecting their first child together, also admits that adhering to a vegan diet is a lot harder while touring.
She also admits that adhering to a vegan diet is a lot harder while touring.
"I have been a little more vegetarian than vegan especially with traveling, so it's a little hard to order food from hotels and stuff when you're vegan," she explains. "Now I'm pregnant, it's like, I can't just order steamed broccoli. That's not going to cut it. I've modified a little bit, but I think I've stayed pretty normal."
Of course the fit 31-year-old singer is also committed to working out, and recently teamed up with Dick's Sporting Goods to create her affordable activewear line called Calia, out March 5.
"I still make it a point to be very active. Of course, I can't push myself -- I am carrying around a little bit extra weight," she tells ET about how she's modified her workout routine. "[I'm] being more responsible and being sure I don't overdo it because that's no good for anybody. Certain moves I can't do. Things on my back, things like that are not recommended."
But still, working out is something really important to Carrie. "I still make it a point to be very active. Doing something, hiking, going for a run, lifting weights, boxing, doing things like that. It makes me feel good. It is great to do something for me, and that is something for me. I think that women should make time. A little time, 20 minutes, 30 minutes."
Carrie, who's expecting a baby boy in the spring, also shares with ET that she and her professional NHL player husband were actually planning on having a baby girl initially.
"He is really excited," she says about starting a family together after being married for four years. "He would have been excited for a girl too obviously. We planned on having a girl. I don't know if you can do that? At some point we'd really like that. We're both really excited and just can't wait to meet him."
She also reveals that the two found out they were expecting on their anniversary!
"We were ecstatic obviously," she says. "We had dinner that night because it was our anniversary the day we found out which was a sweet little coincidence. We tried to wrap our heads around for a little while and which people to tell -- our family, people we work with, stuff like that. It's been really easy and a really nice time in our lives."