“American Idol” winner Carrie Underwood's weight loss has been talked about since she started out on the reality singing contest up to her post pregnancy figure.

While Carrie Underwood was in Season 4 of “American Idol,” she was at her heaviest weight. The singer has since slimmed down and looked fit and fabulous after her son Isaiah Michael Fisher was born seven months ago. How did she achieved shedding of the post baby weight? With the help of a personal trainer, of course.

However, Carrie Underwood disclosed that her weight loss secret in the past also included consuming a dangerous herb in the diet supplements that she took before shifting to a healthier option to lose weight.

"I was taking things with Ephedra in it," she said. "It wasn't the best way. If I could go back and talk to myself I'd be like, 'Here's how you do it the right way.'"

E! News has learned that the dangerous herb called Ephedra, a favorite component in dietary supplements favored by persons with anorexia, was banned for sale in 2004 by the U.S. Food and Drug Administration. Although users lost a significant amount of weight with Ephedra, they were also prone to suffer from strokes, heart attacks and even death.

Meanwhile, Carrie Underwood clarified to People that she does not have an eating disorder. Mike Fisher’s wife rather explained that she just was not taking in enough calories. And no, she’s not starving herself either. “I just didn’t know how many calories I should be eating, ” exclaimed the “American Idol” winner.

The “Something in the Water” singer told Huffington Post that aside from getting conscious of her body weight in the past while she was in “American Idol,” she also regretted how her hair looked in the show.

On a happy note, Carrie Underwood who’s a strict vegan has now ditched the dangerous herb Ephedra and eats a balanced diet as well as coupled it with a daily workout with a trainer in order to achieve a healthier approach to achieve her ideal weight and maintain it.