In 1997, 40 percent of American 5- to 8-year-olds were obese. Ten percent were obese in 1990, up from 5 percent in the late ’60s, according to a National Health and Nutrition Examination Survey. More TV, less P.E. and myriad ways to have sedentary fun have caused the young to expand at breakneck speed.

And I am wondering: Are these lives being ruined in unison, just as my mother’s was decades ago? She was always the only fat child in her class. In my day, in the ’70s, two or three made their hunched and solitary way along the crowded hall. Now hefty kids have lots of company. But does that help?

My friend’s son, at 11, outweighs me. He does not outweigh her, which matches what the New England Journal of Medicine says: Children of fat mothers are three times more likely to be fat themselves. While kicking a football around the park, Scott mentions unprovoked that he could stand to lose 25 pounds or so. Then he shrugs and keeps kicking, executing dives and phantom tackles. He relishes his bigness, tells how he intimidates his smaller classmates, even frightens girls.

Long after he has gone to bed his mother says, “Sometimes his size gets to him.” Not that much, she says. Not like hers got to her when she was 11 and in her yearbook Henry Ramos wrote, “You are nice for an elephant.” Her son suffers less than she did because he has a lot of friends as fat as he is, she says. Fatter.

In the awkward lull that follows I force my eyes down from kitchen shelves crammed with fudge sauce and Cap’n Crunch.

Scott eats no more than any ordinary kid, she says. I wonder. On the day I visit he has pancakes for breakfast. In his sack lunch go a steak sandwich, cookies, a Snapple. After school when his mom is at work he does homework while watching Jackie Chan kick butt in “Rush Hour” on TV. He makes a bowl of popcorn, adds butter, pours sugar over it. White crystals shimmer in the sun.

“This is my recipe,” he beams. He is smart and good-natured. His self-confidence seems real. He sees himself as a world traveler, an athlete and a math whiz. Which he is.

Is he OK? Emotionally, yes, as kids go. But, physically, no. Obesity can seriously cut your lifespan — just ask researchers at the U.S. Centers for Disease Control and Prevention, who contributed their own study last week to announce that fat kills.

Who denies that every child deserves high self-esteem? No one wants fat kids to feel bad about themselves. Look how my mother suffered. Billboards that glorify skinny bodies create hordes of bulimics. Kids have shot themselves after being taunted about their weight.

How do you let a child know he or she is loved and powerful and fine but also, ahem, may be on the road to major health problems? To having difficulty climbing stairs, fitting into theater seats, chasing buses? Is it wrong to discuss with them the possibility of losing weight? Is it wrong not to? That is the dilemma.

For dinner my friend heats up a casserole that is comprised of ground beef, cream-of-mushroom soup, cheese and tortillas fried in oil. Scott dislikes vegetables so she has chopped tomatoes fine and obscured them under the cheese. Then they bring out the ice cream.

Diets do not work, my friend says. She knows this from her own youth, and current research bears it out. The body will not stand that sense of deprivation, forced starvation, and fights back by lowering its metabolism. Which is why, after the diet ends, nearly all dieters quickly gain back what weight they lost.

“Nobody ever told me I was fine the way I was,” my friend says in a voice that stretches thin and cracks. “I tell my son which foods are good for him and let him choose.”

I want to laugh. If my mother had let me choose, at 11, I would have lived on Goober Grape and Hostess Sno-Balls. Her nightmare would have come true.

Parents in generations past said no so readily, shearing our desires off at the stalk. Last night in a public restroom I saw a woman on her hands and knees begging a toddler to please use the toilet.

“No,” the toddler said, and won.

And then there was 13-year-old Christina Corrigan of El Cerrito, Calif., who in 1996 died of heart failure at 680 pounds, amid a morass of feces and pizza boxes in a house she had not left for months. She had not been to school in more than a year. Charged with child endangerment, her distraught mother said she knew her daughter’s health was at risk but had not known what to do. Hoping Christina would decide on her own to stop eating so much, she brought home the fast foods that the girl wanted. (Following a trial that sparked heated debate, Marlene Corrigan was convicted of misdemeanor child abuse.)

Letting kids choose — giving them cash to let them buy their meals — makes many of them fat. Fifty percent of the Americans who eat out on an average day eat fast food. When the local high school lets out every day at 3, I watch a triple stream of kids pulsing through downtown Berkeley on their way to Taco Bell, Burger King and McDonald’s. Some of these kids already are huge.

Parents feel guilty about working, about not being home to make meals, “so they schmear their kids” with treats, says Judith Isaksen, a Berkeley therapist. “For a lot of reasons I am a fanatic about families sitting down for dinner together. But it’s rare. Kids eat in isolation in front of a TV or a computer, which is bound to make them fat.”

One of her young clients is a middle-school girl whom she describes as “extremely overweight.” The girl’s thin parents put her in therapy because they worried about what humiliations she might face at school. She has no friends.

When Isaksen asks her about her weight, “she is adamant about not caring. She insists that it is simply not an issue,” and is irritated that the therapist keeps bringing up the topic. The girl insists her weight has no effect on her life, at school or anywhere. She shrugs. She is, the therapist believes, a master of denial.

“And she walks in here every week eating what I consider a huge amount of food.” Huge bags of French fries. Towering ice-cream cones. Her parents give her money when they drop her off “and probably tell her something vague like, ‘Spend it wisely.’”

Isaksen’s young overweight clients know almost nothing about nutrition, she has discovered. She asks what their favorite foods are. Pizza, they say. Burgers. Duh. They go right out and get them. It is as if an entire generation has forgotten certain basic principles, the way Europe, after Rome fell, forgot how to write.

The fact that so many American kids are so big today is evidence of this country’s advertising skills, says Berkeley family physician Dr. Steven Hart. “Taste buds are exploitable.”

Hart, who admits he takes an aggressive attitude toward his patients’ weight, points out that about 15 years ago the average American ate a pound and a half of sugar every week. Now it’s over 3 pounds, much of it in processed foods like soda and hamburger buns.

This is, after all, a country in which fast-food chains are permitted to contribute to on-campus school lunches. One Big Mac has more fat grams “than you would want in a whole week,” says Hart.

A recent study found that fewer than one-fourth of North American children exercise even half an hour daily. The average child spends four hours a day watching TV, a blend of junk-food brainwashing and lethargy that infuriates Hart.

His youngest fat patients are years away from the mondo acne and excessive menstrual bleeding that often menace overweight teens.

“It’s hard for an 8-year-old to look at diabetes or joint disease seriously,” he says. Or heart disease, breast cancer, stomach cancer, pancreatic cancer. Obesity is an epidemic, says Hart. Self-esteem is all well and good, he adds, “but it’s a health issue.”

Other countries laugh at America the way kids used to laugh at my mother. This is the fat country. There is no other like it. Is it accidental that our current fads in income, shoes and cars tend toward the bulbous?

Watching fat children walk home with groups of friends I see them smile, the girls twirling in skin-tight tank tops. Some glide hand in hand with boyfriends. Are they ringing in a new aesthetic? More than ever, people of all sizes appear on TV — not as the butt of jokes anymore, either. Overweight is clearly no longer anathema, no longer an automatic road to loneliness and shame. This makes me shudder with relief.

Yet, the fact that so very many children in this country are obese — and fat kids tend to become fat adults — sends up a red flag. My mother would say they hate themselves. She would say each one hides a well of sorrow, dark and deep, that someone who was never a fat child cannot know. Maybe she was just born too early to escape that misery. Or maybe that misery now has more company.