Obesity is now being cited by many in the medical community as the most serious public health issue facing America today. They rank it ahead of risky behaviors such as smoking, drug use and promiscuous sexual activity simply because our collective weight problem has become so widespread (no pun intended.)

Public health researchers estimate that nearly 60 percent of American adults are overweight, and the problem seems to be getting worse every day. And in spite of the constant drumbeat of warnings from the people who deal with the serious illnesses that result from a lifetime of overeating and under-exercising, we seem to be reacting to the situation with a collective, double-chinned yawn. Outside of the recent rash of frivolous lawsuits aimed at fast food restaurants, we don’t seem to be doing much about our expanding waistlines.

So what’s behind our lack of motivation? Most of us don’t really like being fat, and no one likes the idea of dropping dead at 50 from a heart attack. So why can’t we put down the doughnuts and the fried chicken and hit the stationary bike once in a while?

The answer is, simply, because we don’t have to. Eating is pleasurable, and it’s easy to do. Exercise is hard work and, in general, not much fun. And you don’t get paid to do it, either. So, with a lack of direct motivation to overpower our natural impulses, a clear majority of us would rather just live with being fat.

Yet even though we aren’t concerned enough about obesity to do much about it, everyone seems inclined to tacitly agree with the medical community that we are somehow in the wrong, and should therefore feel guilty, about living this way. But I am here to question the things that no one else seems inclined to question.

It seems to me that that all living things tend to evolve to fit the environment they find themselves in. If they cannot evolve as that environment changes, they die. Human beings are no exception to this rule, but we are far more complicated than any other living thing on this planet. Our evolutionary behavior is tied not only to our physical environment, but to our social one as well.

Once upon a time physical fitness was a definite asset to the chances of survival for a human being. Continued existence depended on hard work. Those who could chase down and kill wild animals got to eat and reproduce, and those who were weak and out of shape might have gotten to gnaw on the bones, if they were lucky.

But today, physical work is becoming more and more superfluous. Now the people who can sit in an office all day and use their minds are highly prized. And there is little added advantage to being thin and well toned as you sit in your chair and think.

So the human race is becoming soft physically because our culture rewards (or at least does little to discourage) a sedentary lifestyle. The question is — is that such a bad thing?

Obviously that is a purely subjective question, but I think we’d all be happier if we’d just lighten up a bit about obesity. And as that last sentence illustrates, we might be better served by focusing some of the energy that is currently being expended in the “war on fat” towards some of the other evils threatening our society, such as the use of bad puns.