I give a lot of thought to time capsules. I think of things to put in them -- items that if found a thousand years from now would say something about our culture. I have one of the items now. It's a newspaper story about fourth- grade girls. About 80 percent of them are dieting.

The story ran in The Wall Street Journal a little while back and was based on a study of San Francisco kids by the University of California. The Journal was dismayed by the study's findings, and so it went far from the trendy West Coast to the Chicago suburbs and asked 9-year-old girls there whether they were dieting too. More than half said they were.

They were dieting even though they were not overweight, even though they were just kids and their bodies consumed calories like a seal does fish -- even though, to tell the truth, if they were a bit fat it would be no big deal. They don't date. They don't get asked out. If there is a time in your life when you ought to be able to be a bit overweight, it's the fourth grade.

No more. Now the concerns of adults are the anxieties of young children and the neuroses of older ones. (A different story reports that 13 percent of high school sophomores diet by purging themselves.) They worry about divorce because there is so much of it around. They worry about nuclear war because you don't have to be old or fighting at the front to get killed. And now, at the age of 9, they worry about their weight.

The dieting craze is just another example of kids' being robbed of their most valuable possession -- childhood. After all, that's the one time you ought to be able to drink lots of milk and eat all the ice cream that can fit and not worry about calories. If you're a kid, you can eat like that and still look okay -- or, if you don't, what does it matter?

The dieting of children is a pathetic example of form without function. They want to look sexy, but, for the moment at least, it is physiologically beyond them. In fact, they're parodying adult life. If you want to see what we look like to our kids, look at what our kids are doing. They're counting calories. They know the names of all the fad diets. They can talk about bulk and fats, good calories and bad calories and some of them exercise, the Journal reports, to the Jane Fonda workout video. These kids are a mirror, showing us what we look like to them. The girl who reports that her mother uses pliers to zip her jeans is, naturally, on a diet herself.

In "A Distant Mirror," Barbara Tuchman wrote about the 14th century, the epoch of the Black Death, when fully one third of Europe's population perished. Not surprisingly, the century was marked by the extreme youthfulness of the population, maybe half under the age of of 21. There was an absence of adult leadership and mature values. Society in general was childish.

The dieting craze is an example of childishness in our own era. Adults not only want to look youthful, but they look to youth for approval. Take the commercial for a dieting aid in which one little girl asks another how her mother stays so pretty. The girls are French, suggesting sophistication and worldliness. They both admire the mother's beauty. One envies her friend for it while the other, the daughter, is proud as could be. The commercial may be pretty, but its message is not. It says that if you want the admiration of your children, you had better stay slim.

This completes the circle. Children want to be like adults, and adults want to be like children. That neither can be the other ought to be obvious, but it is not. The kids of America are dieting because the adults of America are dieting. If need be, we will risk our health to look healthy, and for women especially the standards are becoming more and more difficult to meet. One researcher says that from 1958 to 1978, the Playboy centerfold got thinner and thinner until now they are some 16 percent slimmer than the average woman their age -- staple not included.

Libya is important, Central America too. But if there a story of our times, the Wall Street Journal has chronicled it -- a candidate for a time capsule that future generations should read, assuming, of course, they can read. As for me, for the sake of our children, I'm going to show some leadership.

I'm off to lunch.