The idea that either James - Cagney or Stewart - should eat at all is somehow sacrilegious; the former smoked and snarled, the latter smirked. Real eating on the silver screen was done only by lonesome cowboys along the Rio Grande (a diet of coffee) or was part of the disastrous domestic life of Lucille Ball and Desi Arnaz, where something always went wrong. Harpo was the only true eater among the Marx brothers, though he tended to eat metallic objects and other people's clothes. Bette Davis nibbled destructively. Joan Crawford was too wrought- up to eat, and the only truly great trencherwoman among the grandes dames of Hollywood, the one who could polish off a pound of sausages as hungrily as another husband (the once-winsome Miss Taylor) seldom ate publicly on screen - despite the fact that in a half dozen encounters I do not remember her ever not being a table.

The trouble with public eating in the arts is that there are two problems: first, it is a messy and unappetising activity (consider yourself a voyeur and look about you, in close-up, in any restaurant, and you will realise that to look at eating is almost as gross as to look at sex) and secondly, it interferes with what you're supposed to be otherwise doing: singing, declaiming lines, wooing or saving the Alamo.

In this respect, the only happy artists are writers and painters. Quite apart from the Dejeuner sur l'Herbe, which has a postcoital, postprandial air to it, the subjects of paintings are forever reclining on couches and swallowing great bunches of grapes, not to speak of leaving apples about in their studios to rot. After all, though neither film nor stage, with a few rare exceptions, has made food a real subject, painters have - in that mysterious genre known as the still life, which is to painting as the deep freeze is to the household, a place where the food is kept that you cannot just reach out and eat.

Writers, who often spend their early years in a state of considerable hunger, tend to dwell lovingly on food as soon as they have had a sufficiency. I have reached some 700 pages in my anthology of food scenes in literature without even beginning to exhaust the subject. Of course I haven't included biography and autobiography, both of which show writers to be relentless chompers, save for those who specialise in liquid diets. (I have a picture on my wall showing the poet Robert Lowell in the act of crushing out a cigarette on a succulent double lamb chop, but that is to be compared with his Stalin-loving peer, the Chilean poet Pablo Neruda, who not only ate well but actually co-authored a whole book in praise of Hungarian cuisine.)

I understand there is a play about (I have not seen it) which concerns the preparation of spaghetti; but on the whole, apart from a grisly banquet in Macbeth, not much eating goes on on stage. Richard Loncraine's Richard III doesn't eat, for instance: he urinates. His winter of discontent is self-induced and things would have gone better for him had he had an appetite - which the director, an expert cook, has.

In fact, this is one of the more curious duplicities involved in the world of make-believe, that, in my experience, all Hollywood, and most actors, directors, producers, agents and such, spend a great deal of their time eating while their creatures on the screen seem to eschew it altogether. The same is true of opera, for breaking into song with your mouth full is no easy task, yet off stage singers, like dancers, are creatures of stupendous appetite. In my youth it was a dancer who regularly bankrupted me: she required two pounds of red meat after every performance and none the less remained as sylph-like as my wallet.

In short, though the arts are greatly concerned with human appetites, it does seem to me that they neglect an aspect of reality which, were it not for the fact that it is so ugly to watch, we could all use a little more acquaintance with. Though it is true that the methodical movement of the jaws, the slithering of the tongue, the smacking and licking of the lips, are hardly pretty, it is still through what a man eats or how he eats that he is frequently best revealed. Though it is now obligatory in biography to consider the darker secrets of sexuality, though copulation is the most animal of our actions and appetites, still I would really rather watch Napoleon eat than be behind an arras while he and Josephine were hard (or gently) at it. When I look at the famous photograph of Tolstoy with his vast family sitting out of doors at Yasnaya Polyana before an array of jamjars, I know jolly well that he was not the puritan he made himself out to be.

In the same way, every free inch on the walls of my quite large kitchen is covered with pictures of my friends, and a surprising number of them seem to have been caught in the act of eating or drinking (the Slavs mainly the latter). There we all are, going for food in our various ways. Hannah Arendt's shapely legs crossed in relaxation reveal her satisfaction in the meal she's just finished; Wystan Auden looks rumpled and surfeited; Mr Bellow picks his teeth. Elsewhere, Joseph Brodsky (now just departed) looks across at Derek Walcott's not-quite-finished chocolate cake, and Seamus Heaney studies a half-emptied, or half-full, glass. Good, if incoherent, dialogues have taken place.

And, I ask, if Cagney had eaten before he gunned his colleagues down, what would he have eaten? Only in Tom Jones do we get the ultimate relish of a peach in the clutches of a good, open, sensual mouth. Otherwise, on stage and screen, food (viz Fawlty Towers) is generally comical, disorienting. Why? The answer surely is that we are locked in our private pleasure and we'd rather not, and probably shouldn't, watch someone else's