Jennifer Hudson's weight loss memoir

Jennifer Hudson is working on a memoir about her struggle with weight.

The Academy Award-winning actress has signed a deal to open up about her body issues and reveal how she dropped 80 pounds (36kg).

The currently untitled book is set for a January release.

Hudson was dubbed "the big girl" as a contestant on "American Idol," before transforming her body for her Oscar-winning performance as Effie in "Dreamgirls" by gaining over 20 lbs (9 kg).

Last year the star became a Weight Watchers spokeswoman and has gone from a size 16 to a 6.