Q What's your opinion on meditation? Does it improve mind and body, or is it just a spectacular waste of time?

A A few years ago I was a cynic on meditation - I didn't see how it could work. Now I'm a fan. Chinese and American experts working together set up a random controlled trial in 80 students, who either practised meditation or were taught simply to relax their muscles for 20 minutes a day. After only five days the meditating students scored better on the ability to maintain attention and on mood. Asked to perform difficult mental arithmetic, the meditators' blood cortisol levels - a measure of stress - rose substantially less than those of the relaxers. It's a good start for meditation, but we need longer studies to show that the benefits are lasting. I don't see it doing harm.

Q I'm a bit pear-shaped, in that my hips are a lot larger than my bust. We want to start a family. Is it best to slim down first?

A I'm not sure how by slimming you can lose pounds preferentially from your hips, rather than from elsewhere on your body. If you are not particularly overweight but just a bit "hippy", at least take comfort from a surprising study coming from the US National Centre for Health Statistics. It showed that women with wide hips and relatively narrow waists gave birth to children who later performed better at tests of cognition than those of other women. Unbelievably, the authors proposed that extra fat on hips contains fatty acids that are crucial for the infant's developing brain. I'll believe it when I read another study agreeing with them.

Q We have heard a lot recently about eating the wrong foods and cancer. bacon, red meat, processed foods, salt, refined sugars, alcohol, and smoking, even vitamin supplements have all been blamed for causing cancer. I can't stop all of them - so is there a league table of how much of each gives what risk?

A Good question. Smoking is by far the worst of these habits - 20 a day raise your risk of lung cancer by between 20 and 40 times. For women it's nearer 40 than 20. In contrast to that, if you have a family susceptibility to colon cancer, your risk of actually contracting it rises by about 20 per cent for every extra 50 grams you eat per day. As for all the others, the risk is relative to the amounts you eat and how genetically susceptible you are to cancer. If I had to give a league table I would put smoking at the top, alcohol a reasonably close second, obesity a fairly far-off third, and the others (processed and red meats, salt and dietary supplements) quite a long way behind, but still something to think about. If you want to lower your risks further, then daily physical exercise, plenty of fruit and vegetables and keeping a normal body shape will help. But nothing's certain.