*Jennifer Hudson, who recently revealed that she’s lost an additional 20 lbs. since April, showed off her hard work at the star-studded seventh annual Black Ball for the Keep a Child Alive foundation in New York on Thursday.

The Weight Watchers spokesperson worked the red carpet in a strapless black gown. [See above photo.]

Earlier this month, Hudson, 29, said she’s still getting used to her new look. “I go into the store and they try to put me in 4s and 6s and I’m like [she looks over both shoulders] ‘Who are you trying to talk to?’” says the former size 16 star.

Whitney Houston, Usher, Sade, Jay-Z, Beyonce and Janelle Monae joined pregnant host Alicia Keys and her hubby Swizz Beatz for the NYC benefit to support Africa’s children and their families with HIV and AIDS. See photos below.

Alicia Keys and husband Swizz Beatz

Sade

Whitney Houston

Janelle Monae

Jay-Z and Beyonce

 

Usher

Usher and Alicia Keys