Leona Lewis is almost unrecognisable as she shows off dramatic weightloss in revealing thigh-split gown at animal charity event in LA

She shot to fame after winning the third series of the X Factor in 2006. 

But Leona Lewis was almost unrecognisable as she debuted a dramatically slimmer physique at the Mercy For Animals Annual Hidden Heroes Gala in Los Angeles on Saturday.

The songstress, 32, displayed her slender frame in a form-fitting gown which revealed her toned torso with cut out panels.

Leona's midriff looked minuscule, and a sultry thigh high slit exposed the entire expanse of her toned leg.

Speaking to Women's Health last year, Leona detailed her healthy lifestyle now she lives in Los Angeles.

Her exercise regime is varied: 'I do four hour-long workouts per week – everything from SoulCycle to hiking with my dog.'

A lifelong vegetarian, Leona eats plenty of whole foods, including kale salads and tofu, and she limits her vices to stay in shape.