Jillian Michaels Doubts Beyonce Used Master Cleanse

Michaels was out in Malibu this weekend, when we asked about rumors that Beyonce dropped the baby weight by going on a Master Cleanse ... a 10-day program where people are only allowed to consume tea and lemonade mixed with maple syrup and cayenne pepper. "Don't do the Master Cleanse," Michaels told us bluntly ... "It's bad for you."

Back in 2006, Beyonce told Oprah she shed a TON of poundage by using the program for 14 days ... but now, Michaels insinuates Beyonce is more educated about the dangers of the Cleanse ... and HIGHLY DOUBTS the singer would ever do it again.