Bristol Palin Denies Mother Sarah is Too Thin: She's 'Really Fit' (PHOTO)

"Dancing With The Stars" contestant Bristol Palin recently lashed out at claims that her mother Sarah Palin is too thin following growing criticism over the mother of five's substantial weight loss.

Bristol, 21, was recently asked whether Palin, 48, is too thin, to which responded by explaining her mother's fitness regimen.

"No, I think [Mom] is really fit. She is lean. She's beautiful ... She's a big runner and likes to do everything," Bristol told In Touch magazine. "My mom is an awesome athlete and definitely my motivation. She keeps me going to hot yoga every morning and doing stuff like that."

Palin, who became a national phenomenon as the Republican Party nominee for Vice President in the 2008 presidential election, recently stunned onlookers during a shopping trip with her daughter Willow in California's Studio City. In response to criticism and questions about her substantial weight loss, Palin explained that she and her family members are currently writing a fitness book to help others lose weight.

"Our family is writing a book on fitness and self-discipline focusing on where we get our energy and balance as we still eat our beloved homemade comfort foods!" Palin told

Meanwhile Bristol has faced criticism of her own following her emotional meltdown on a recent episode of "Dancing With The Stars." The single mom recently accused her dance partner Mark Ballas of "not being there" for her and of not wanting her as a dance partner before storming out of the room in tears, which talk show host Anderson Cooper suggested may have been a ploy on her part to create a juicy story line.

"Anyone on a reality show knows that to get attention, you have to have a have a wardrobe malfunction, throw up, have a breakdown, have a storyline," Cooper said on his syndicated talk show "Anderson."

"Bristol Palin is a genius because last night she developed a storyline that made her very sympathetic," he added.