There is a lot of concern lately about Americans being overweight. Not one to overlook the problems of health - and the lack of it - in this country, I decided to find out for myself just how weighty the issue is here in Salt Lake City.

I'm a believer in the rules of scientific research, so I did my best to set up a reliable and accurate experiment to gauge the extent of obesity in the city. I sat next to the window in the food court at ZCMI plaza and kept track of the people who walked by on South Temple while I ate my lunch.About 100 people walked past (give or take a few I might have missed when I got up to refill my soda and pick up more napkins). Of those, only five or six appeared to be what I would call really overweight. Sadly, those were all women.

Oh, there were a few middle-age men with stomachs that resembled wash tubs more than washboards, but they didn't make me cringe in revulsion. And they seemed healthy and cheerful otherwise.

There were also a number of women who might benefit from a few days a week out walking or pushing a lawnmower. But obese? No, I don't think so. If I were a doctor, I wouldn't have worried about the vast majority of those folks I saw downtown that day. They were a pretty healthy-looking bunch.

But it seems doctors are worrying more than I am. In fact, some much-quoted scientists are predicting that, if Americans continue their current eating and exercise habits, nearly every single one of us will be fat early in the next century - which doesn't give us much time.

I don't believe it.

The part of this prediction that bothers me is the definition of "fat." I just don't buy those tables that say if you're this tall you should weigh this much in order to be healthy. My family - and I'll bet lots of others - skews the heck out of those charts as predictors of good health, happiness or long life.

I believe the people who make up your family tree and the genes they've passed along to you have much more to do with whether a few extra pounds - as defined by the AMA charts - are going to affect your health. Some bodies are meant to be heavier than average, and they are just as healthy being heavy as other people are being lightweight.

Take my mother and Jim Fixx.

According to the charts, my mom should lose a good chunk of weight. She's never been what most people would call slim (at least as long as I've known her, and she was 35 when I was born). And she has developed a few health problems, including high blood pressure and mild diabetes.

But she's also 84 years old and has lived an active life as a farmer's wife, mother of four and grandmother of who-knows-how-many. Would she have been happier if she had forgone the types of food she loves and programmed more exercise into her daily routine? I doubt it. She's already outlived a husband whose weight never got above 160 and has exceeded the expected lifespan of a woman born in 1914 by a good many years.

Fixx was a guru of the thousands who took up serious running in the '70s and '80s. His body fat was probably about 3 percent, and he spent more time pounding the pavement every day than most of us spend sitting in traffic - and that's a lot of hours.

And he dropped dead in his 50s.

Sure, there are people who overdo the Doritos in a big way and whose hearts have a tough job getting blood out to the far corners when they climb one flight of stairs. Like the poor, they are always with us.

But for those of us who eat reasonably well and get some sort of regular exercise in addition to whatever we do to make a living, it's counterproductive to constantly worry about 10 or 20 extra pounds. Those pounds just may be a family legacy that isn't going to hurt us as much as worrying about it and jumping from one diet to another.

The pursuit of happiness is more important - and more healthful - than the pursuit of a svelte body.