The first time that Hayden Panettiere realized she was tabloid fodder, she was 16 years old. A paparazzo had snapped her wearing shorts, bending over, and the photo was published along with commentary about her supposed cellulite. After that moment — and a brief dalliance with the comments section on the photo — she decided to start filtering out the press about herself. “But, sometimes, things would get through,” she says. “My publicist would get a call asking for comment about something about my life, and I’d have to decide, do I go no comment and let them put out whatever version they want? Or do I comment to get ahead of it, but be forced to talk about things that I really don’t want to?” The actress, now 36, says that in the decades since, there have been countless moments of misinformation — and that it’s what led to, and gave her the bravery to, finally sit down and write her memoir.…