Back in 2011, rumors swirled that Jay-Z and Beyonce were embracing a partial vegan diet as a way to stay healthy - and at the time, help Ms. Knowles to avoid putting on too much weight during her pregnancy. While that was all third-party gossip, we now have confirmation from Jay-Z himself that this time around the famous couple's switch to a vegan diet is the real thing. 

"On December 3rd, one day before my 44th birthday I will embark on a 22 Days challenge to go completely vegan, or as I prefer to call it, plant-based!!," Jay-Z wrote on his site LifeandTimes. "This all began a few months back when a good friend and vegan challenged me to embrace a “plant-based breakfast” every day. It was surprisingly easier on me than I thought…"

Jay-Z, who added that his wife will be joining him, said the timing of this shift was significant to him. "There’s something spiritual to me about it being my 44th birthday and the serendipity behind the number of days in this challenge; 22 (2+2=4) coupled with the fact that the challenge ends on Christmas day…It just feels right!"

The inspiration for the vegan challenge comes from friend Marco Borges, an exercise physiologist and founder of 22 Days Nutrition, a vegan, organic, and gluten-free food and lifestyle company. Borges was also responsible for helping Beyonce drop her 57 pounds of baby weight after the birth of her daughter Blue Ivy. He told Life & Style that the singer's diet included at least "one vegan meal a day because this typically gets people to eat more greens than they normally would."

Jay-Z, who calls this challenge a "a spiritual and physical cleanse," adds that he will be posting progress reports on how the two fare with the plant-based lifestyle. 

"I don’t know what happens after Christmas," he adds. "A semi-vegan, a full plant-based diet? Or just a spiritual and physical challenge? We’ll see…"

Related on MNN:

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Beyonce, Jay Z embrace 22-day vegan challenge
Jay-Z says he expects the diet to be both a 'spiritual and physical cleanse.'