ANNETTE'S OSCAR DIET IS ALL WET!

Swimming helped bulky Bening lose 12 stubborn pounds

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ANNETTE BENING was having a heck of a time shedding 12 pounds she piled on two years ago until signing on to play legendary long-distance swimmer Diana Nyad, the 64-year-old gal who paddled from Cuba to Florida in 2013.

Nyad was the first person to make the grueling 110-mile swim without a shark cage in just under 53 hours - and the 65-year-old actress has clinched an Oscar nomination for her gritty role in the flick.