Janet Jackson is desperately fighting the flab to drop the pounds she has gained  since unveiling her slimline new figure last year.

Seen in Paris dressed in a dowdy, black shapeless outfit, which appeared to be concealing extra pounds, the singer looked a complete contrast to the stunning picture of her taken in March earlier this year.

The self-confessed yo-yo dieter has gained a reported two stone in the past five months and friends she is desperate to shed almost three stone in time for her world tour.

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Yo-yoing weight gain: Janet Jackson has blamed her two stone weight gain on her boyfriend's junk food habit. Seen left in June, and right in March

The source told Closer magazine: 'Janet's such an extreme yo-yo dieter. She's piled on the pounds really quickly over the summer, and is now desperate to lose 40lb, just over three stone, in time for her world tour.

'But Jermaine has been stocking the fridge with pizza, fried chicken, chocolate and ice-cream.

The source told Closer magazine: 'It's causing friction in their relationship.'

Janet, 42, has had an ongoing battle with her weight for years. Her yo-yo dieting saw her dramatically gain 4st in 2006, before losing it in four months.

By July 2007 she was pictured looking bulky again after regaining some of the weight.

The sister of reclusive singer Michael Jackson is said to be miserable at her current weight of over 10st.

She now has a nutritionist and a chef, and is sticking to a 'strict diet of 1,700 calories a day'.

Janet Jackson arriving at the Costume Institute Gala in May with music producer boyfriend Jermaine Dupri