Let's face it folks, Oprah does what she does for her business. There are very few plus-size performers who stay that way once they get famous, or who stay famous if they go from being skinny to plus-size.
I mean, if we all hired full-time cooks, trainers and psychologists like she has, we'd be able to utterly transform ourselves too. You take away all that, and I'd bet money she'd turn back into the spitting image of the Oprah we remember from the early days.