Any centre of any city on any Friday or Saturday night has the same vibe. It’s as if there has been a fire at the prick factory and everyone has escaped. I always try to stay away. If I have a standup gig in central London, I leave immediately after the show and get back to my safe bed as soon as I possibly can. Alcohol brings out the worst in some people – and no one has ever drunkenly told me something I really needed to hear.

This happened on a recent Saturday. I had rushed out of a gig and got the tube to Kennington, south London, where I was waiting for my bus. I’d forgotten my headphones so I was hyper-aware of all the drunk people walking the streets, getting on the tube, going into the city centre to seek shelter in nightclubs where the music, fortunately, is so loud that no one can hear them speak, which means they never have to develop personalities.

I saw four young men approach. I was not surprised when they spoke – I expected it. “Oi, you fat cunt!” one of them said. “Oink oink,” said another. The rest is a blur because I focused on whatever was on my phone. It hurt, of course. As it would have hurt anyone.

Not having any idea what to do, I put it on Facebook, sharing it with my friends and followers. I just needed to do with that experience what I usually do when I do standup – take ownership of it and express myself. It felt a bit better.

I woke up the next day to see my post had been shared thousands of times. It was even in newspapers and on blogs. “Danish Comedian Sofie Hagen Says: They Shouted Abuse At Me” and “Men Shout At Danish Comedian – What Happens Next Will Shock You” and other such clickbaity headlines. People had posted such comments as, “I am really sorry that happened to you,” and “Those guys were massive pricks.”

It stopped hurting. The hurt immediately disappeared. And all I was left with was anger.

This is not a once-in-a-lifetime thing. This happens on a daily basis to hundreds of thousands of fat people everywhere. This is happening now, perhaps at this very moment, to a 14-year-old girl who has yet to realise that her body’s worth is not dependent on what the media tells her it is. It is happening to children. It will happen again. Maybe tonight when I am walking home from a gig.

This will happen online – some people will even be inclined to write it in response to this very article. People will tell me to stop promoting obesity and to just lose weight. People will tweet at me without having read the article and pretend that they are worried about my health. Some will even tell me I am making it up. Some fat people will say they have never experienced anything like that.

This will happen on TV, in movies and on the radio. As I am writing this, my fat friend told me that last week she was hit on the head with a kebab – and yes, that is a really funny sentence – I am but human, and “kebab” is a funny word and that is a funny image. It is, however, unforgivable.

It has always happened and it will continue to happen. But now it’s different. I no longer feel good when people pity or comfort me afterwards. I do not need people’s kind words. I need their fury. I need them to be angry with me. I need them to act.

I need everyone to realise the repercussions of making “fat” mean lazy, stupid, unattractive and unhealthy. Fat is not necessarily unhealthy, and skinny is not necessarily healthy. I need people to stop saying “You are not fat, you are beautiful,” as though they are mutually exclusive. I need people to feel angry – not at these four idiots at Kennington station – but at the society that created them.

I need people to demand change. Tweet companies who use fatphobia to promote their products, email TV shows portraying fat women as sexless, evil or motherly and goofy. Call out your friends, family and teachers.

If you won’t then OK. But keep your pity to yourself. I am a healthy, beautiful, intelligent, active and creative fat woman. I’m doing what I love for a living. I have friends and family who love me. I am good. I am no longer sad. I am just angry, and I wish you were too.

• Sofie Hagen is on tour and will be performing Shimmer Shammer at the Soho Theatre in London, 5-17 December