After signing on to be the spokesperson for the Nutrisystem diet plan, Janet Jackson debuted her dramatic weight loss on Monday in a new video and photos for the weight loss campaign.

This is what success looks like, 45-year-old Jackson says in the video for Nutrisystem Success released on Monday, sporting a tiny waist line in slim black trousers and white collared shirt.

The weight loss comes after a long battle with fluctuating weight, as Jackson reportedly weighed over 180 pounds in 2006.

However, Jackson did not reveal how much weight she lost since she signed on as a Nutrisystem spokeswoman in December.

For Janet, it's about feeling good, a Nutrisystem rep said.

Many have speculated that her weight loss is anywhere from 25 to 50 pounds, as seen in the photos of the pop icon wearing a tangerine colored dress which hugs her tiny waist.

Jackson said in December that the Nutrisystem helps her maintain a healthy weight when combined with working out six days a week, including three mile runs.

I've come a long way. I haven't reached where I want to be. I'm a work in progress. I haven't reached my success. I know I will get there with Nutrisystem. I am happy with who I am and the person I am, she said.

In December, Jackson released a book entitled, True You: A Journey to Finding and Loving Yourself, in which 45-year-old Jackson explores weight loss and gain in a candid account about her battle with fluctuating weight over three decades of her life

Some of my battles with weight have been very public, Jackson wrote in the book. But most of them have been internal. Even at my thinnest, when my body was being praised, I wasn't happy with what I saw in the mirror or how I felt about myself.

Jackson said criticism from producers and her brother, Michael Jackson, fueled tension.

It really got to me and I took it way too seriously, Jackson said. But the more he joked about my big behind, the more determined I was to be thin. Even as a little kid. On certain days I decided simply to starve myself - no breakfast, no lunch. Because ours was a show business family, we were pretty much on our own. Other than the extremely rare holiday dinner, we didn't have regular sit-down meals.

Jackson admitted she used food in an unhealthy way as her comfort, eating to compensate for depression and stress.

While Jackson said she turns to food when in a funk, performances and the tight schedules helped her maintain a healthy weight in those busy periods.

At some point I learned to control my eating, especially when I had something to do - for example, a record, concert, or TV appearance, Jackson wrote in her book. I had the ability to work out, stay on a strict regimen and make it happened. I stayed disciplined.

Janet Jackson is the latest celebrity to endorse a weight loss regime program including the likes of Jennifer Hudson for Weight Watchers and Mariah Carey for Jenny Craig.

View the slideshow to see photos of Janet Jackson's weight loss journey over the years.