June 4, 2014 -- Hollywood's tots are taking a page from Queen B's book -- they're taking a challenge to go vegan.
Unlike the 22-day vegan diet that Beyonce and Jay Z made famous, this one's just two weeks long. And it's for kids.
Created by yogi-to-the-stars and author Rainbeau Mars, the kiddie cleanse began Monday and has 300 participants so far. It was inspired, she said, when she and her daughter Jade were cooking at Jade's school. The other moms told Mars there was no way the kids would eat the vegetable soup they were making.
"I also noticed that probably 95 percent of the kids had never helped in the kitchen," she said, something she thinks is crucial for getting kids to eat healthy.
Celeb kids have joined the challenge. Johnny Sequoyah, 11, of the show "Believe" said that in the two days since she started the cleanse, she already feels better. She loves donuts and french fries, she said, but has learned that when "you're eating only junk food, it makes you really tired. Whenever I finish a hamburger or doughnut I do feel tired and sometimes in a bad mood after." She said she likes the smoothies, and also kale salad with lemon as her favorite "healthy substitute."
Those are two of the foods Mars highly recommends when it comes to kids. "Keep it simple," when it comes to kids' cleanses, she said. Chia pudding is another favorite. "I almost cried the other day seeing all these kids posting photos of the chia pudding they made. We might know how healthy and simple it is, but now they're spreading the word."
Kid rapper Lela Brown, who was a contestant on "America's Got Talent" has also signed up. "I decided to do the cleanse because I thought it would be a really cool experience to try being vegan," she said. She also said she was hoping for more energy and to "clear out her pores."
It's those kinds of results that appeal to the kids participating, Mars said. "You tell them it will make them feel better and stronger and they want to sign up."
But Mars was quick to point out that when it comes to the kids, this cleanse is not about weight loss. Besides health benefits, she wants the kids to really think about where their food is coming from. Avoiding animal products, including "cholesterol, antibiotics and any fear we may be ingesting is good for the planet and good for us all."
Health professionals don't necessarily agree that when it comes to kids, cleanses are a good idea. Dr. Richard Besser, ABC News Chief Health and Medical Editor, said that Mars is "well-intentioned" in teaching kids to understand more about vegetables and getting them off processed foods. But, speaking as a pediatrician, he said this is "wrong in so many ways." In addition to saying it's OK to eat junk food and then do a cleanse to make it all better, he said it's bad science. "Kids don't need a cleanse, our liver and kidneys do fine with that."
The vegan cleanse challenge is available through a daily email; anyone can participate by emailing email@example.com.
Editor's note: This story has been updated to include information about possible health concerns related to kids' cleanses.