Robbie Williams has admitted he "could write a book about self-loathing".

The 47-year-old singer has addressed his weight loss and ongoing body dysmorphia after fans pointed out his slimmer physique in a video shared by wife Ayda Field, 44, earlier this year.

Robbie shared a drawing on Instagram of two characters with one saying "It's gone too far" while the other said "Aw, bless you" with the caption: "My ideal goal weight is people being worried about me."

He wrote alongside the image: "So, If a genie appeared and said you can either have your super power be the ability to fly or eat what you want and remain at your goal weight?

"I would go for Goal weight eating everyday. What about you?

"I could write a book about self loathing where my body image is concerned. Like pure self hatred, The ugliness of feeling ugly.

"I'm body dysmorphic and on top of being dysmorphic at times I can be 40+ pounds over weight.

"So you can imagine what my mind see's. Or maybe you can’t either way its a f****** disaster."

The former Take That star admitted "the struggle is real" and it's something he has dealt with for his whole life.

He continued: "At the moment I'm skinny ..But me being me my mind is going ‘F****** great Rob, you managed to get skinny and now your old, congrats, golf clap’'

"The struggle is real, The sadness shocking. I’ve had it all my life. And it wont abate.

"What is it that is hard wired in us, that is so calloused, that makes self acceptance and self love so difficult that it seems impossible?"

Body dysmorphia disorder (BDD) - which can affect people of any age and gender - is a mental health condition which sees soemone worrying about flaws in their appearances which are often unnoticeable to others.

Robbie - who has opened up about having Botox - insisted he wasn't "fishing for compliments" with his emotional post and hoped his candour would help someone feeling the same way.

He continued: "Anyway, I'm not fishing for compliments. I'm sharing for sharing sake. I'm sharing for some sort of release I guess.

"And if someone else recognises themselves in the words I’ve written maybe it helps both of us."