It seems miracles really can happen. As the world watched Britney Spears’ debut last week on How I Met Your Mother, it was obvious that the former pop star was looking good, dare we say it, even back to her old self!

“It looked like Britney had lost 15 pounds in four weeks,” a source close to the singer tells OK!. And sure enough — gone was the bloat, the ratty hair and the puffy face. In their place, a slimmer, fresh-faced girl with a smile on her face and determination in her step.

So how did she do it? “Britney’s a pro at losing weight fast,” a Spears pal tells OK!. “She can drop seven to 10 pounds in two weeks.” Although now, in Britney’s case, it’s about adopting a longterm plan she can stick to. Sources say Brit has given up her old unhealthy weight loss habits, like popping laxatives and diet pills.

The 5-foot-4 singer has also replaced soda and fast food with five, small protein-packed meals a day. Doing so has enabled her to peel off the pounds. “Eating five meals a day will boost your metabolism,” Dr. David Katzin of Fresh Diet, a meal delivery program tells OK!. “In fact, by eating superclean, Zone balanced foods at each of your five meals, you will find that your metabolism goes into overdrive, becoming extremely efficient at burning calories.”

And get this — Brit’s even cut back on her Starbucks Frappaccino fixes! “Britney used to come in every day. Now she just comes in from time to time and orders a lighter version,” a barista at a Malibu Starbucks tells OK!.

To complement her healthier eating habits, Britney works out regularly as well, although you probably won’t see her jogging around her neighborhood. The recovering pop star enjoys daily dance workouts at L.A.’s Millennium Dance Complex, where sources tell OK! she does squats along with chair and pole dancing. When she does run, it’s on a treadmill at home, away from the spying eyes of the paparazzi.

“I don’t like to work out because my legs get bulky,” Brit has said. “Dancing makes me leaner.”

Whatever it is she likes to do, it definitely seems to be working. Britney finally appears to be back on the road to success!

WENN