The Do You Want the Truth or Something Beautiful? singer explained that seeing her mother suffer from breast cancer has made her realise that it's "superficial" to alter your body if it's not for medical purposes.
She told Hello: "I agree with cosmetic surgery for medical reasons - my mother had breast cancer and I think it's very sad when somebody has no choice in what happens to their body.
"But seeing what she went through made me think that, if you're a healthy human being, why would you even go there? It's very superficial to change what you have. I think everybody should focus on inner beauty."
However, the London-born star admitted that she was fortunate to have a mother who made her feel confident.
She added: "I think it's important to feel good inside and feel that you're worthy. I'm really lucky because I was brought up by my mother, who filled me with possibilities - she made me feel like every dream was possible.
"There's nothing better than achieving your goals, whatever they might be."
Faith recently admitted that she gets mocked for her Cockney accent.