Two days after starting the "Body Revolution" movement on her social networking site LittleMonsters.com, Lady Gaga showed off her body in a series of tight, skimpy outfits during a concert in Zurich, Switzerland.

(Splash News)

The singer has been criticized in the past week for gaining weight, but she confidently wore a low cut, thong body suit and fishnet tights during the concert, only briefly covering up with a jacket and t-shirt.

Gaga launched the "Body Revolution" section on LittleMonsters.com Sept. 25 to "inspire bravery" and "celebrate with us your 'perceived flaws.'"

She also posted a picture of herself, eyes closed, wearing a bra and panties, with the caption: "Bulimia and anorexia since I was 15." She's encouraging her fans to do the same.

"Hey Guys its Gaga," she wrote. "Now that the body revolution has begun, be brave and post a photo of you that celebrates your triumph over insecurities."

The 26-year-old pop star made headlines last week after photos of her performing in Amsterdam showed her figure looking fuller than it has in the past. The pop star recently told radio host Elvis Duran that she's gained "like 25 pounds" and is dieting but noted, "I really don't feel bad about it, not even for a second."

"I have to be on such a strict diet constantly," she said. "It's hard because it's a quite vigorous show, so I tend to bulk up, get muscular, and I really don't like that. So I'm trying to find a new balance."