The 'Your Body' hitmaker is said to have changed her diet to regain the figure she sported in 2010, reported Contactmusic.
"She did it all on her own. She goes online and picks out her food. She's been working hard. She wants to lose a bit more. But she feels great," a source said.
The mother-of-one also recently started doing a lot more working out.
"It's more of a mind-body thing for her. She believes in exercise that she enjoys, doing strength work as opposed to cardio," the source added.