1. How healthy are you?

I am a fitness fanatic, and I think what people call hypochondria is just an awareness of your own mortality. The first half of my twenties were spent taking drugs with rock bands, and because I knew a lot of people who keeled over and died, I'm pretty health conscious.

2. What exercise do you take?

Most men in my world - that is, the London metropolitan world of journalists and novelists - look like fat blobs from ancient Rome. I train twice a week with a boxer and I'm the same weight now I was 30 years ago. It takes a lot of effort, but it's also fun punching things.

3. Do you worry about your weight?

Yes. A lot. I think it's key to everything. I'm 12st 7lb and if I go over that I feel like a great big boiled egg. I weigh myself every morning and I'm aware that absolutely everything counts. If I go to the gym for two hours, that will show on the scales the next day; if I stay at home and eat a jam donut, that will show, too. I make the most of what God gave me, which wasn't much. I'm not cute enough to be vain, but at the same time I'm in excellent shape. The only thing that stops me wearing low-cut Amy Winehouse jeans is the disapproval of my wife.

4. Is sex important to you?

Yes. Yes. Sex is very important to me. It's the foundation of a happy marriage. I've always had to make an effort to not think about it, to be honest.

5. Do you drink/smoke/take drugs?

I'm a moderate drinker. I enjoy a couple of Asahi Super Dry or a few glasses of wine, and stop before the leglessness kicks in. Both my parents died of smoking-related lung cancer, so I am anti-smoking, though I did smoke myself until my dad died 20 years ago, so I understand if people go through a nicotine habit. I think drugs are a young person's game. They're ridiculous for anyone over the age of 25 and, whatever a person's age, they're always a dead end. You are always chasing (and failing) to recreate that first hit.

6. Have you ever had therapy?

I had couples therapy once with my girlfriend, about 20 years ago. She was from New York and just like a character from a Woody Allen film. I'm not against therapy if it works, but it felt pointless for us. Our therapist said a very wise thing: 'Some people just don't get on.'

7. NHS or private?

Both. I have private healthcare, but I think the NHS does a fantastic job. My daughter was sitting on my shoulders last summer, I slipped, and we threw ourselves at the mercy of the Royal Free in Hampstead. They were brilliant. You can never live without the NHS.

8. Are you happy?

Yes. I couldn't have anticipated my working life would turn out so well. I am doing what I wanted: writing columns and novels. My happiness is largely built on my marriage of 16 years, and becoming a dad again in later life. My daughter is a blessing, and I now count the years God gives me.

· Tony Parsons's novel My Favourite Wife is out now, published by HarperCollins, £17.99

· The following correction was printed in the Observer's For the record column, Sunday April 6 2008. In the article above we incorrectly stated that Tony Parsons was 47. He is 54. This has been changed.