Frankly, I find tall men a bit of a turn-off

HOW DOES that song go? "Six-foot two/Eyes of blue/Something, something I love you..."

It doesn't matter anyway because at the rate people are growing these days, particularly teenagers, being 6ft 2ins is nothing special and certainly not enough to merit a tribute in song. There is absolutely no need for a man to be more than 5ft 9ins, well, make it 5ft 10ins. Anything above that is not only redundant, but frankly unsociable.

I say this not from malice or envy, although I admit there are times when I could use another couple of inches, but from a practical point of view. Big people take up too much space in theatres, in trains, in planes, in general. When my 15-year-old son's best friend Charlie stays for supper, I have to put in the table extension or he just wouldn't fit.

Charlie is 6ft 4ins and at 15 he's still growing. His shoes, size 12, look like narrow boats. When Charlie and another school friend, a mere six-footer, came to stay with us in the holidays, I bought them child- rate tickets (they are under 16) for their return three-hour bus journey to Glasgow Airport. "Are they unaccompanied?" asked the bus driver suspiciously. "Yes," I said. "Then I am not authorised to take them," he said. But what could possibly happen to them, I protested? Anything, said the driver. They could be kidnapped, he added unconvincingly, looking at my two young giants with their maritime footwear and backpacks the size of walk-in wardrobes. In the end I had to give it to him in writing that I took full responsibility for the children's safety. But watching the pair of them knocking into the other passengers as they tried to cram into their seats, it occurred to me that it wasn't their safety that needed underwriting.

Nutritionists are always telling us that our improved diet is making people bigger. All that meat and orange juice only upper-class folk used to get. Charlie, like many of my son's friends, is a vegetarian. He eats only plain spaghetti, admittedly by the bucketful, topped with grated cheese. He has it for breakfast, lunch and supper, the sole variation in his diet being the width of the pasta or the colour of the cheese.

Personally, I think it's less to do with diet than lifestyle. Apparently we do most of our growing in bed. A friend, worried about her daughter's height, was advised by the doctor to keep her in bed and give her a chance to grow. When they come to stay, my son's giant friends spend most of their time in bed. Even when they're officially up and about, they are lolling semi-recumbent in armchairs, playing football games on TV. If they were actually playing football they wouldn't have time to grow. Footballers aren't huge, far from it. They're small and skinny with squeaky voices, like David Beckham.

Being tall is becoming almost as obsessive with young people as being thin. Why else do they make platform shoes with five-inch heels? As for the latest report that platform shoes will have to carry government health warnings because they're so dangerous - a teenage girl in Tokyo fell off hers and broke her neck - I'm all for it. They are dangerous. I fell off mine coming down the escalator at Leicester Square tube station and it was 10 times more awkward than falling off skis, where at least you have ski sticks to help you up. Maybe platform shoes should only be sold with platform poles - neck-brace, wrist guards and kneepads optional.

The puzzle is why any Japanese girl should want to look six inches taller. They're supposed to be petite, perfect miniatures, that's half the secret of oriental mystery and exoticism.

At the risk of being called a heightist I genuinely feel that tall people, particularly men, don't try as hard as small ones. They seem to equate their extra inches with extra intelligence, extra nobility, extra charm. It's always small men who give up their seats to you in trains.

The one and only time I ever flew Concorde I sat next to an oilman from Texas complete with check shirt and Stetson who used me as an arm-rest for the entire journey. He couldn't help it - he was 6ft 7ins and built like a tank.

"Wouldn't you be better flying first-class in an ordinary plane with more space," I managed to say somewhere over Newfoundland. I'd been trying to speak to him for two hours but my mouth was wedged behind his checked shoulder. "I guess," was all he said. See what I mean.