Let's face it, we're all in denial about something or other. I'm a fan of the Chicago Cubs. Need I say more?

Still, are you as astounded as I am by the depth of denial some people demonstrate when it comes to their personal health and safety? This summer, my inbox has been deluged with studies and news reports that document a widespread lack of self-awareness among Americans about their own precarious physical status and a refusal by many to take even simple steps that might improve their well-being.

Let's start with our nation's weight: Isn't it staggering to think that within 20 years, 50 percent of the U.S. population will be obese? And that while a large majority of Americans know full well that excessive pounds contribute to chronic illness, most do absolutely nothing about it? The Lancet in August reported on a study predicting that the increase in obesity by 2030 will lead to 8.5 million more people with diabetes, 5.7 million to 7.3 million more cases of heart disease and stroke, and up to 670,000 additional cancer cases. MedPage Today in July described the results of the SHIELD report, which found that among respondents at high risk of developing type 2 diabetes, just 57.3 percent said they were even considering a plan to lose weight and 17.2 percent said they would rather take medication than change their lifestyle. While 62.5 percent of respondents recalled their physicians suggesting they increase exercise, only 12.7 percent of those with a high risk of type 2 diabetes said they were physically active, and 67.3 percent said they performed little or no exercise.

So used have we become to what a researcher at the University of Texas Medical Branch in Galveston calls "the fattening of America" that one in four overweight women "misperceive" their weight. As obesity numbers climb, many women identify overweight as normal, not based on the scale but how they view themselves, the researcher, Mahbubur Rahman says. And that makes them less likely to do anything that will help them lose weight and avoid chronic illness.

One last point about the obesity epidemic: It isn't just hurting individuals, which is bad enough, it's hurting the health care system and the nation's finances, too. A 2009 study in Health Affairs estimated that obesity adds $20 billion to $34 billion in Medicare costs every year. And an article in the Miami Herald last month pointed to another study showing that preventing obesity in one typical 70-year-old could save up to $39,000 in health care costs for the rest of that person's life.

But denial can be found in all kinds of unhealthful behaviors besides packing on the pounds.

A study published in the August issue of Arthritis & Rheumatism found that more than 40 percent of men and more than half of women with arthritis in their knees did not even get moderate exercise, such as brisk walking for 10 minutes a week, despite the fact that it could ease their inflammation and pain.

Another example: An emergency department nurse at a hospital in Florida once asked me if I knew what she and her colleagues called motorcyclists who refuse to wear helmets. Her answer: Organ donors.

And a couple of weekends ago when I was attending a wedding in Alabama, a local woman and her baby were killed in a car crash. Speculation was the mother was texting while driving.

Tired of my harping yet? Let's not even get started on people who drink too much alcohol or let their kids have too much soda pop or refuse to follow doctor's orders once they're discharged from the hospital. And so on.

I don't agree with the blanket criticism of health reform, but some people have said it doesn't do enough to promote personal responsibility, and there may be some truth to that. My question is, how do you define personal responsibility? Take smoking, for instance: Is it just the smoker's responsibility to quit? Or do the tobacco grower, the cigarette manufacturer, the retailer and the politician who votes to give the growers tax subsidies bear some responsibility for adding to the nation's health care burden? I don't know the answer, I'm just asking.

And what is the responsibility of the health care provider in all this? Hospitals have certainly taken the lead in educating the public about disease and disease prevention. They work with others in their community to promote healthful behavior like getting exercise and eating right. They offer wellness programs to their own staff and to employees at other local businesses.

But ultimately, it's up to the individual to decide whether or not to do what's best for himself or herself. And for those who choose denial, all the health care provider can do is treat their ailments and comfort their survivors.

Bill Santamour is managing editor of Hospitals & Health Networks. Follow his tweets at www.twitter.com/wsantamour.