What does it mean when someone "has let herself go"?

Does it mean she's fat?

• Fat, unkempt or unattractive.

• It means the same as someone "has let himself go"

• you know the answer, girl.

• Here's your answer:

  https://www.google.com/

• Oh R2. There wasn't ever anything to let go of, you poor womyn.

• It can mean a lot of things. Here's a good start:

  http://tv.yahoo.com/news/-80s-child-star-tina-yothers-embraces-the--what-not-to-wear--process-132531859.html