By Shay Spence
Updated December 02, 2020 02:13 AM
Credit: Jerod Harris/WireImage

Reba McEntire has always stayed in great shape, but it doesn’t come without some discipline.

“I have to watch what I eat and exercise and cut back,” the 61-year-old country legend tells PEOPLE, highlighting one particular diet that’s worked best for her. “In the early ’90s, I was on Fit for Life. That’s the slimmest I ever was,” she says.

The basic principles of the plan are simple: “Don’t mix your carbs and protein,” she says. “Stay off sugar. Anything white, just stay off. But not mixing carbs and proteins seemed to work really well. Instead of having potatoes and steak, just have steak and vegetables. If you’re going to have carbs, then have our carbs with vegetables.”

Though McEntire doesn’t follow any strict diet anymore, she maintains a more manageable approach to staying fit — and isn’t afraid to indulge every now and then. “Portion control works best for me now,” she says, adding, “I do like to go on vacations and that’s when I really splurge. I love Mexican food — chips, salsa and guacamole. And then chicken enchiladas and a really neat dessert. That’s my cheat day.”

These days, though, the singer has been most focused on her work, recently announcing her new home collection, Rockin’ R by Reba — available at Cracker Barrel locations nationwide — and an upcoming acoustic holiday album, My Kind of Christmas, which will also be sold at the restaurant chain starting September 2.

WATCH: Reba McEntire Answers Your Questions!

So how does this new partnership with the comfort food eatery factor in to her dietary habits? “It’s feel-good food,” she says. “Probably not a place you go when you’re on a diet, but I always find something to eat there no matter what my weight level. If I’m doing really good, I can have the chicken and dumplings, and if not, I’ll have the veggie plate.”

When she’s not working on her multitude of business ventures, she plays the role of grandmother to the children of Kelly Clarkson and her husband Brandon Blackstock, the son of McEntire’s ex-husband Narvel Blackstock. “The kids are just growing up a storm,” she says of River Rose, 2, and Remington, 4 months. “Kelly’s kicking back into the music business after having [the baby], and Brandon manages her. They’re all busy and loving life.”