Jennifer Hudson has opened her own weight loss centre.

The singer-and-actress - who has shed over 80lbs and five dress sizes following the birth of her son David in August 2009 - launched the Weight Watchers Jennifer Hudson Center on Sept 27, 2011 in her native Chicago.

Jennifer - who became the face of Weight Watchers last year - said: "I never thought I would make it to have my own centre. I'm so honoured to be here and see this day."

A portion of the facility's profits will go to children's charity the Julian D. King Gift Foundation, which was set up by Jennifer in memory of her late nephew, Julian King.

The seven year old's body was found in a car just three days after her mother, Darnell, and brother, Jason, were shot dead at the family's Chicago home in October 2008.

Jennifer is extremely proud of her weight loss but recently claimed she was unaware she was overweight until she moved to Hollywood.

She said: "I didn't even know I was considered plus-sized until I came to Hollywood. I thought I was the perfect size!

"[One day] an interviewer asked, 'How does it feel to be plus-sized in Hollywood?' I looked around, like, 'Who is she talking to? Oh, me? I'm plus-sized?' In the neighbourhood I'm from in Chicago, a 16 is normal. But in Hollywood, everyone looks exactly the same, so I stood out."