White hot! Janet Jackson shows off dramatic weight loss in sexy plunging gown at amFAR event in Cannes

PUBLISHED: 23:15, 24 May 2012 | UPDATED: 11:36, 25 May 2012

She's been a yo-yo dieter all her adult life, but Janet Jackson says she finally has a handle on her ideal weight.

And she certainly looks like a woman who is at ease.

Last night she arrived at amFAR's Cinema Against AIDS annual ball at Cannes in a stunning bright white Pucci by Peter Dundas gown that showed off her slim, toned frame.

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Vision in white: Janet Jackson looked incredible for amfAR's Cinema Against AIDS 2012 event in Antibes last night

Perfection: Janet's Pucci was tweaked and coaxed into place on the white carpet

Rocking it out: Jackson was stunning i her simplicity, showing off her newly svelte figure

The 46-year-old paired the show-stopping number with shoes by Giuseppe Zanotti and jewelry by Pomellato.

Turnaround: Janet's weight has yo-yoed for most of her life but she's hit a purple patch again

The singer has become a spokesperson for NutriSystem after her most recent successful attempt to battle the bulge.

Michael Jackson's little sister is dedicated to helping others shed weight, as much for their health as anything else... as she has admitted that she put her own in danger by being overweight.

She told Prevention magazine: 'Health was always a concern. When I gained weight in 2005, my nutritionist was very worried. I was close to having diabetes.

'Even when I lost it and then gained quite a bit back, there was always the thought of heart disease.'

But she credits her trainer with helping her get motivated, she said: 'I don’t like to work out, and I get bored easily. (Trainer) Tony Martinez is great. When I’m getting ready for a tour, I’ll work out with the dancers. He’ll put us in teams and we’ll do all sorts of drills and races.'

She adds: 'I think people really connect with the idea of someone who’s gained and lost weight in a very public way, and also someone who’s an emotional eater.'

In the commercial, released last month, a newly-slim Janet said: 'This is what success looks like'.

Back in 2006, she weighed 180lbs (12st 12lbs) before slimming down. However following the death of sibling Michael three years later, she began to pile on the pounds again.

She has championed the brand on Twitter, simply saying: 'Nutrisystem works. #SUCCESS'

In her book, True You, release last year, the Indiana-born star wrote: 'For more than three decades, I’ve struggled with yo-yo dieting. Some of my battles with weight have been very public.

'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.'