my daughter and her appearance

My daughter just turned 7, she has recently started to talk a lot about her appearance, he desire to be skinny and her obsession with being 'tanned' when we were on holidays has continued since we have come home. It has made me very concerned. 

She has always been a terrible fussy eater but always ate what she would like but even those foods have become less and less. 

Im real struggling to get a decent meal into her, and feel like she has lost some weight. 

she mentioned today at bath time about how she can feel her bones on her back. 

i work in mental health and have always been careful with the language i use around her, i am not a dieting person we have normal meals and we are very open and talk about our emotions and have a very close relationship. 

any help or advice would be great.