Kierra Box, 18, student activist

My general health is brilliant, though I am ill at the moment with some unidentified infection. I am very into my immune system - I do the whole echinacea thing, taking supplements whenever I am feeling run down. I am rubbish at sleeping - I get about seven and a half hours a night - but I eat fruit. I have been counting and try to get five portions of fruit and vegetables a day. My friends are aware of "the five" but not many do anything about it.

I have been on a health kick since Christmas because of all the chocolate I ate. I tend to feel rubbish in the winter and am very worried about getting flu (I get it very badly). But I don't worry about things like cancer - you just assume it's something older people get.

When I hit 18, though, I started worrying about the things they start telling you that you need, like smear tests and breast exams. I worry more about not taking the right precautions and not doing the screening properly than I do about the actual diseases. I do feel quite negative about my future health. I sometimes think it would be just my luck to get something like cancer or a chronic illness, or have an accident that would leave me in a wheelchair. A friend of mine was hit by a car last summer and is still unconscious. They don't know if he'll wake up.

I do drink a bit but I don't like the effect it has on my body. Many of my friends drink a lot in the pub but I'll only have one. They don't worry about their livers - they worry more about the hangover they'll get. Most of my age group look at the reports on TV and think, that's not going to happen to me now, so they don't worry about it. I don't smoke - I don't like it, and I have relatives who have died of lung cancer - but virtually all my friends do. Most think they will stop when they finish their A-levels, or their gap year or university: they think the health problems are just things that will happen later in life.

I get virtually no exercise - like most of my friends. The ones who walk or cycle tend to do it for environmental reasons, not for fitness. There's no more surefire way to put young people off physical exercise than enforced PE at school - it's torture unless you are really into organised sports.

Robert Macfarlane, 27, writer and academic

I don't worry about my health because I've never been unhealthy. I do worry about being fit, though. I desperately need the general sense of wellbeing that running gives me, since I'm in such a sedentary job as a university teacher, sitting in my padded armchair seven hours a day. I run every two to three days.

My father and brother are both doctors, and my mother has always worked in hospitals, so I think this has given me a reasonably functional approach to my health. I am generally suspicious of things like multivitamins (the advertising seems so manipulative), but I'll take about five of those gigantic vitamin C tablets, the ones that look like horse suppositories, whenever I feel ill (about every six months). This seems to work.

Occasionally I indulge in a bit of forecasting and wonder what it would be like to be over 70 - the only thing that would horrify me, I think, would be having an accident that prevents me using my legs. Nothing upsets me as much as lethargy or lassitude. I do have peers who have died - of disease and in accidents - but I think having four living grandparents, all well into their 80s, and healthy parents, contributes to my sense of invulnerability. Illness and death have a genuine remoteness for me.

Becoming a father (my daughter is six months old) didn't make me any more aware of my mortality. My wife worried a lot when she was pregnant about her general health and I became quite angry about the health police that descend on you with blue flashing lights during a pregnancy.

The culture of paranoia and guilt, the pathologising of pregnancy, really annoyed me. If anything, witnessing the birth of my daughter made me feel how robust we all are. Ultimately, I just want to die before my daughter does, but right now I'm still in my bullet-proof 20s.

Sheena McDonald, 40s, broadcaster

I'm on a strict healthy-eating regime at the moment - I wouldn't call it a diet, just eating less food - mostly because I want to get into natty little jackets, rather than for my health. I put on weight when I was recovering from my accident. I was hit by a police van, driving on the wrong side of the road, in 1999. I had severe head injuries and post-traumatic amnesia.

But it hasn't shaken my attitude towards my health. I've always been blessed with good health and I certainly don't think any more about it now than I did 20 years ago. I have a robust gene pool. I don't take vitamins or anything - I can't see the point. I eat a balanced diet, drink moderate amounts of alcohol and don't overdo anything.

The doctors didn't think I would ever get back to work, they were just hoping I would be able to look after myself - wipe my own bottom, eat my own yoghurt or whatever.

Surviving has not made me feel more fragile, though I suppose the curtain between life and death does seem more gossamer to me now. I also feel that death is nothing to fear. Like most people, I probably live in a state of denial about the future.

I don't think about things like breast cancer, even when it comes close to me. I just think, it'll never happen to me. I have no interest in dying - I don't think about it at all. I would like to remain healthy to the end, but I can't say how I would like to die. I don't see myself leaving early, though. Having survived my recent graze with death I'm quite optimistic.

Jenni Murray, 50s, writer and broadcaster

I'm a terrible hypochondriac - this job does feed into that - but I can recover pretty easily. I believe your health is a genetic lottery. I do a lot of work with the Parkinson's Society (my mother has it) and recently went to a dinner where I met two or three people in their 30s and 40s suffering terribly from it. Then the following night I went to a dinner for Charles Wheeler, who's 81, fit as a fiddle, bright as a button, smoking and drinking away. You are so much at the mercy of your genetic inheritance. I do worry, but then I very quickly think, stuff it.

When I became perimenopausal, and went on HRT I got quite depressed and put on a lot of weight. Now I am probably a couple of stone overweight. I occasionally dabble with the Atkins diet for health and aesthetic reasons (I can't pretend it wouldn't be nice to get into a size 12, though I suspect those days are over).

But I hardly do any exercise. It's so hard to fit it into my life. The fittest I've ever been was during my pregnancy era. I did yoga - it's the only form of sport or exercise I've ever found acceptable. I am convinced it's why I had such easy pregnancies and births. I gave it up, though, after my second child. With two small children and a full-time job, it's too much to fit in fitness.

I have about half-a-dozen bottles of vitamins on my desk, and another half-dozen at home. When someone says something like 'vitamin E is fantastic', I'll buy it. Then I'll take it for a week or so and then forget. I'm a smoker - 10 or 15 a day - and try endlessly to give up. My eldest son doesn't mind my smoking, but my youngest hates it. I voted for the smoking ban in the BBC to try and cut down but now the balcony is where the most interesting people are. If I get a life-threatening illness I just want good pain control and a doctor who'll pop me off when it all gets too much.

Michael Foot, 90, former leader of the Labour party

I have never worried much about my health. I really don't think about it. But I know I certainly wouldn't be here now if it weren't for the NHS. I had a big motor accident way back in the early 1960s, coming back from my new constituency. My wife, Jill, was driving - she went over a crossroads and we were hit by a lorry - it went into the side of me. My whole chest was smashed.

We were rushed to Hereford hospital and our fine Irish GP, who knew everything about us, and about the NHS, arranged for the best specialist to come up from Birmingham and do the operation the following day on my chest. The NHS has saved me so many times. I had a prostate operation 10 years ago that saved my life. And I have had eye tests and hearing aids fitted - all on the NHS, which is still a wonderful service.

Nye Bevan, a great friend of mine, was a huge proponent of preventive medicine - he wanted everyone to have proper treatment for eyes, hearing and teeth. He would be absolutely furious to see that dentistry is no longer free. Nye took a tremendous interest in medical matters and helped me personally. I had suffered from eczema for years. I used to get it so badly I sometimes couldn't go out. Nye gave me a lamp - I've still got it - and it cleared it up completely.

I used to smoke 60 to 70 Woodbines a day and I also suffered from asthma - it started when I was at Oxford - which could be very frightening. But after the accident I stopped smoking and the asthma cleared up. I started when I was 21. My grandfather had said if I hadn't started by the time I was 21 he would give me £25. Now I'm the biggest bloody anti-smoker in the country.

My health really is pretty good - I'm luckier than most. One of my legs isn't so good because of arthritis and I had a hearing aid fitted three or four years ago, though I can still talk on the phone without it. Not being able to do my hearing aids properly is my only imbecility.

I do take some vitamin things for my blood, prescribed by my doctor, and have lots of healthy things to eat. Now when I go to my GP, we talk about painting, mostly.