This may not sound appealing, but Fergie's secret to staying slim is vinegar. She downs shots of vinegar, which her trainer explains flushes out the fat in the colon and helps to digest food.

Fergie Ferg says, "I do vinegar shots. It has to be organic apple cider, unfiltered. Two tablespoons. For some reason I've noticed a difference on my stomach."

Maybe girlfriend is trying to put those pregnancy rumors to rest for good!