Jennifer Hudson has long been the target of media scrutiny for her bodacious bod, but the new mom has been sporting a slimmed-down look as of late thanks to Weight Watchers.

Hudson, who gave birth to son David Daniel Otunga Jr. just 7 months ago, announced to PEOPLE today that she has signed on as the latest spokesperson for the weight-loss company.

Of her weight loss, the actress, who gained over 20 pounds for her Oscar-winning role as Effie in 2006's 'Dreamgirls,' says, "[It's] A lifestyle change, not a diet."