Demi Lovato refuses to let ''bad hair and make-up days'' define her.

The 'Heart Attack' singer, who entered rehab in 2010 for treatment for an eating disorder, drug and alcohol addiction, and self-harming disorder, says she is much more body confident now and doesn't need to have a ''thigh gap'' to feel beautiful.

The 22-year-old said: ''For some reason this whole thigh gap thing has kind of swept over what people think is beautiful. And if you have that naturally then that's totally fine, you're still beautiful. But my body doesn't naturally have that.''

The brunette beauty wants to promote a healthier image and posted a photograph of her bikini body on Instagram last weekend, with the caption: ''Regardless of what society tells you these days... You don't have to have a thigh gap to be beautiful. It is possible to love your body the way it is. #fitness #health #acceptance #selflove''

She explained: ''I wanted to show my fans out there who don't naturally have [a thigh gap] that [it's] okay. You don't have to have what you see in the magazines if that's not what your body naturally has.''

But Demi hopes that her critics will stop focusing on her appearance.

She told E! News: ''Your body is going to change, your looks are going to change, you're going to have great hair and make-up days, you're going to have bad hair and make-up days--it doesn't define who you are. At the end of the day, who you are is who people really see.''