Jenna went au naturel for the September issue of Women's Health, and yes ... she addresses her split from Channing Tatum and other personal issues, but who are they kidding? The pics are selling these magazines.

Okay, a little about the breakup -- Jenna says, "It’s okay for a relationship to change into a new form that is actually better for both people involved, and I think maybe that’s what shocked everyone so much – that it can be a positive thing."

Now, back to the nudity! She thinks it's no big deal because, "I’ve been a dancer my entire life, so I’m used to little clothing.”