"The Dark Knight Rises" star lost 25 pounds (11 kilograms) in two weeks to play Fantine in the 2012 film, and while it seemed like she was experiencing a career high because of the accolades she received for the role, the actress admits she "wasn't in a good place" at the time.
"I'd lost an unhealthy amount of weight in two weeks," she tells People magazine. "I didn't know anything about nutrition. I taxed my body, and my brain bore the brunt of it for a while. I just felt very anxious and very lost at that time."
"That weight loss was not a long-term good thing for my health, and it took a really long time to come back from it. And I was still really sick because of it."
Anne also reveals she wasn't able to enjoy all of the positive experiences she was going through in her personal life because of how she was feeling at the time.
"I had just turned 30," she says. "I had just gotten married (to Adam Shulman). Even the most positive thing can be upheavals to your identity. So to just have this moment and not really know who I was - and the moment when you just feel like you're on display - it wasn't a comfortable feeling. And I didn't do what I hoped that I would if I ever found myself in that moment."
However, she has since been able to move on to a more positive place in her life.
"Life went on beyond it," she adds. "I feel much emptier now. It would have been nice if (feeling good) had happened then, but I'll still take it."