In May, one of Rimes's Twitter followers referred to her as "scary skinny" after the singer posted a picture of herself in a bikini.
The country singer responded at the time by saying: "This is my body, and I can promise you I'm a healthy girl. I'm just lean. Thanks for your concern, but no need to be."
Playboy Club star Cibrian has now weighed in on Rimes's eating habits, telling Access Hollywood Live that he doesn't understand why people feel the need to criticise his wife.
"It bothers me because, obviously, I know she's healthy. She eats more than I do sometimes. She's just a very [responsible] eater, as far as what she eats," Cibrian joked.
"She eats pretty healthy, but she works out pretty hard too and she actually takes pride in the way she looks and it's a shame that people will jump on the bandwagon just because she is fit. And she's far from unhealthy."
Cibrian also cautioned that it isn't right to judge Rimes based solely on photographs published in the press.
"Whenever you get a picture taken of you, there's always an angle that looks unflattering for anybody and it's unfair to use those pictures as the basis of the way that you actually really look. She's in fantastic shape and very healthy and I love the way she looks," he remarked.
The Playboy Club airs Mondays at 10/9c on NBC.
> LeAnn Rimes: 'Love is my greatest accomplishment'
> Eddie Cibrian: 'LeAnn Rimes looks perfect to me'
Watch Eddie Cibirian talk about his wife LeAnn Rimes's eating habits below: