Speaking to Shape magazine, the 31-year-old pop star admitted that keeping her famous booty in shape has got harder with age.

‘I like it, then again, I hate it. I’m in my 30s now, so I have to work harder to keep it "up,"’ she said.

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Britney took to Twitter on Tuesday to express her excitement at being on the cover of the magazine, tweeting a picture from the shoot along with the caption:

‘Check out @ETonlineAlert tonight for a look behind the scenes at my @Shape_Magazine cover shoot! 7:30 PT’

Britney credits yoga and low-calorie meals from Nutrisystem for keeping her weight in check, but admitted that she struggles to stick to the healthy food plans.

'Dieting is tough… because my specialties are spaghetti, brownies and chocolate chip cookies,' she added.

And the recent snaps of the mum-of-two indulging in a savory snack and eating ice cream whilst watching her son’s football game last month, would indeed suggest just that.

Despite her struggle to maintain a healthy diet, things are looking up for Britney and not only on the body front.

Following her split with fiancé Jason Trawick earlier this year, the The Till The World Ends singer has been spotted with David Lucardo, who she reportedly started dating in March of this year.

Britney also revealed last month that she has written a track for this summer's Smurfs 2 soundtrack.

'Remember that surprise song I recorded for my boys? It's coming soon! #OohLaLa for #TheSmurfs2 :) Stay tuned for more...,' she teased on Twitter.

Additionally, recent reports suggest that the superstar is in talks to sign a two-year contract with Planet Hollywood Resort and Casino's PH Live theatre.

The Hold It Against Me singer is rumoured to be performing at the LA residency every weekend beginning in November of this year.