Born in High Wycombe and educated at Oxford, Brand worked on BBC Radio 4 comedy show Mouth Trap, before writing and starring in her own sketch shows: ITV2's Katy Brand's Big Ass Show, for which she won best female newcomer in the 2008 British Comedy awards, and Channel 4's Comedy Lab Slap. Her debut novel, Brenda Monk is Funny, is based on her own experiences as a standup comedian and is published next month.

Brenda Monk is Funny started as a crowd-funded project. Why choose that route?

I was meeting female authors who were feeling – even the established ones – that they were losing control of the books they were writing and being pushed into a genre that didn't represent what they had written. But I didn't want to self-publish as it was a first book. I read about Unbound and thought: "That sounds amazing. This is the thing." The book is sort of "pre-sold" because everyone who has pledged has already bought the book. They get it first and then it's available to anyone in all the normal ways.

Your standup heroine, Brenda Monk, gets jittery if she hasn't performed in front of an audience for 48 hours. Do you experience that?

It's not something that I have. But it's a trait I have observed around what I would term "pure stand-ups" that I know. It's an addictive need to be out there in front of strangers trying out material. It becomes a compulsion. You blast 20 minutes of your "best self" to an audience and then you lift off again and you're out of there. For some people, that's compulsive. The adrenaline is addictive too. That massive spike when you walk out... For me, the thrill of it was not enough to compensate for the things I found difficult. So live comedy is not something I do a lot anymore.

Why do you prefer acting and writing to live performance?

A lot of people have a misconception about standup that people only work in the evening and all day they're gambolling around in fields with lambs or in the pub. I found my day was being ruined. I wouldn't be able to sleep until 4am because even if I had come in at midnight I couldn't relax. I would sleep in late and then be in this state of low-level agitation all afternoon. It was like wearing an uncomfortable coat all day and I could only take it off for 20 minutes in the evening [on stage] and then I'd be on a mad high and couldn't sleep again. It just didn't suit me.

Is the BBC right to introduce its "no all-male panels" for comedy shows?

Yes, I am in favour. In an ideal world, I don't think anyone would want this kind of announcement. But we don't live in an ideal world. There's this argument: "Let it change organically and then it's more authentic." I don't buy it. It should have happened by now. There are dozens and dozens of brilliant comedians who happen to be women who deserve a place there. It has a knock-on effect on the economy of standup. If you block people from doing those shows, then they have less money (or no money) to go to Edinburgh and do new material.

You read theology at Oxford and used to attend church as a teenager. What do you think about religion now?

I think religion is a fascinating study of the evolution of humanity. I think to dismiss religion is blinkered. It's how we cope with our self-consciousness and curiosity. But I can't go along with anybody who thinks their version of God is the only version of God. I thought that even when I was a slightly loony fundamentalist Christian. I don't have a specific faith now but I'm not anti-religion. I'm one of those awful people who says: "I believe in spiritual things."

You're also about to be in a film, Walking on Sunshine, with Greg Wise and Leona Lewis; it sounds like an 80s version of Mamma Mia!.

It's a really fun summer film. You go along and have a laugh and sing along to the 80s music and enjoy a glass of wine afterwards. It's not something to write a thesis on. My role is a character called Lil who is an old friend of two sisters who are both falling in love with the same man and we're all on holiday together. Some acting jobs require you to stand waist deep in a ditch. And some are about dancing on the beach at sunset in Italy. It was really fun to make.

You have 61,500 followers on Twitter: life-enhancing or soul-destroying?

Both. There was that early burst of excitement of getting to know people you wouldn't normally connect with. Now it's more like people are asking: "What can be done with this thing?" The honeymoon period is over. We're figuring out how the marriage is going to work. When I first started on Twitter, I was more active than I am now, although I have short bursts of shouting like a noisy child when I get cross about Ukip. Then I wander off for a bit and play with my crayons.

You once danced – with some verve – to Beyonce's Single Ladies for Sport Relief. Can you still do the dance?

There was a period of 12 months afterwards when all my good friends were getting married. People would come up to me at weddings and say: "They really want you to do Single Ladies." And everyone would form a circle until I was forced to enter that circle and perform the dance. I used to hear it come on and go and hide in the toilet. I may have since blocked it from my mind as a self-preservation technique. I haven't tried for a while. Maybe this afternoon I'll see if I can still do it.

Brenda Monk is Funny is published by Unbound (£8.99) on 31 July. Walking on Sunshine is in cinemas from 27 June