When Megan Crabbe was younger, she suffered from anorexia.

The body positive Instagram star has opened up about this battle in the past, but a recent post has called for people to stop comparing mental illness to body sizes.

Posting under the handle @bodyposipanda, Megan wanted to talk to her followers about a comment she had heard lately: “Teaching overweight people to accept themselves is the same as encouraging anorexia.”

To this Megan wrote: “First of all, STOP COMPARING A MENTAL ILLNESS TO A BODY SIZE. Stop treating 'anorexia' and 'overweight' as if they're two ends of the same spectrum.

“Because when you say that here's what you're actually doing:- Completely misunderstanding mental illness.- Reinforcing the idea that you can't be fat AND have a restrictive eating disorder - you can.- Making the assumption that all fat people have binge eating disorder - they don't.- Making absolutely no sense.”

The author took the comment to mean that overweight people who have a good self-image has the same effect health-wise as those with an eating disorder. This is something she ardently disputed.

Megan continued: “Take it from someone who's been both medically classified as 'overweight', and nearly lost their life to anorexia – there is no harm that the fat on my body could cause me that is worse than anorexia.

“And I don't just mean physically. The effect that eating disorders have on a person's mental health is catastrophic. When I was in the depths of my anorexia I lost every part of myself, all that was left were the numbers, the counting, and the voice of my eating disorder telling me how worthless I was every second of every day on a loop.

“Saying that fat people loving themselves is in ANY way comparable to the living hell of having anorexia, is disgusting. And couldn't be any further from the truth. Because encouraging people to accept themselves, to recognise how worthy and wonderful they are in the body they have is the HEALTHIEST thing, mentally and physically, that a person could ever do.”

She encouraged her followers who are overweight or are suffering from an eating disorder not to listen to naysayers who don’t know a thing about their health.

The post has garnered an incredible 40,000 likes with Megan’s followers cheering her on.

One user commented: “Thank you for this incredible response. It is so wise and measured. I have not had an eating disorder but the quote made me gasp out loud with the shocking way some people think.”

Anorexia nervosa is a serious mental illness that affects around 165,000 people in the UK. While most sufferers are women, one in ten are men. The most common eating disorders in the UK are anorexia, bulimia and compulsive over-eating.

If you want to talk to someone about an eating disorder, you can call the Beat helplines between 3pm and 10pm on : Adult Helpline: 0808 801 0677 and Youthline: 0808 801 0711.