The Love and Other Drugs star said that now she's 28 she finally feels more comfortable in her own skin.
'My identity used to be shaped on my appearance so much,' she told Elle Magazine. 'I don't think I was shallow - I just think I was young.
'I focus on other things a lot more now.
'I've hit the point in my life where I understand that being skinny is not sustainable, and nor is it advisable, and nor is it enjoyable.'
She said that she also refuses to have botox because she doesn't want to 'erase' who she is.
She said: 'From the age of 25 to 27 – and this is a little embarrassing to admit – I looked under my eyes every single day, because I thought, 'It's going, it's going, it's going!'
'And then I realised the other day they're not wrinkles; they're smile lines. If you look at pictures of me from a young age, I've been smiling the same way since I was little.
'And I had that wonderful moment when you realise, 'That's who I am.' Botox would erase that.'