The fact is that if we continue to grow fatter, lead sedentary lifestyles and smoke, many baby boomers will die prematurely. But even more are going to live long, unhealthy lives and end up with chronic illnesses that cost millions of dollars to treat. Poor habits will eventually kill you, but they could kill your quality of life first.

Management of chronic diseases in America accounts for 75 percent of all health care costs. In his book, Sick: The Untold Story of America's Health Care Crisis and the People Who Pay the Price, author Jonathan Cohn points out that Americans spend more money on diabetes than any other single disease.

Instead, we could adopt healthy lifestyles in an attempt to ward off disease and chronic illness. Better yet, our health care system and employers could support us in our efforts, which would not only keep us healthy, but also help rein in health care costs. The Washington Post reported that the historic anti-smoking legislation Congress passed last week could curtail "the 400,000 deaths and $100 billion in health care costs attributed every year to smoking in the U.S."

Some have criticized the legislation as unnecessary government intervention, but these types of actions may be needed to advance what President Obama referred to as "the cause of healthy living" in his speech to the American Medical Association (AMA) on Monday. "Five of the costliest illnesses and conditions -- cancer, cardiovascular disease, diabetes, lung disease, and strokes -- can be prevented," he said. "And yet only a fraction of every health care dollar goes to prevention or public health."

Let's look at obesity, which affects half the U.S. population and has become an epidemic, as we've heard many times. In a recent Fox News interview, Ken Thorpe, a professor at the Emory University School of Public Health said that the number of obese people in the U.S. has doubled since 1985, and this has led to a 30 percent increase in health premiums.

Obesity is a problem that needs to be averted if we want to contain health costs and live not just longer, but better. From an obstetrician's standpoint alone, obese and overweight women experience higher rates of infertility, miscarriage, toxemia and diabetes in pregnancy, and they're also more likely to have a pre-term delivery, cesarean section or stillbirth.

Unfortunately, many patients do not respond to the usual incentives to change their ways. My father died of heart disease at age 67. He was obese and sedentary and had poor eating habits. And he refused to shape up despite pleas from me and other family members, or the prospect of enjoying his young grandchildren.

Doctors are not much better at encouraging patients to change. The American College of Obstetrics and Gynecology, for instance, recommends that nutrition and exercise counseling should be offered to all obese women who are either considering having a baby or are already pregnant. As I pointed out in an earlier installment in this series, doctors get paid very little to sit down and counsel a patient. An obstetrician actually stands to make a lot more money on the extra procedures, tests and visits involved in taking care of a pregnant woman with diabetes than on any counseling they could provide to prevent the condition.

I am not suggesting that my fellow OBs wish this or other conditions upon their patients, but physicians can and should play a greater role in prevention. When I worked at Kaiser Permanente, we learned that we could safely reduce our c-section rate, and we not only saved money by decreasing the number of days patients spent in the hospital, but babies' outcomes were also better. The doctors realized over time that good medicine could be cost-effective by having the best outcomes. My colleagues and I worked together to achieve care like this.

In his speech to the AMA, President Obama said that building a health care system that promotes prevention rather than just managing diseases will require all of us to do our part -- citizens, doctors and employers. Going forward, we need to find innovative ways to reward people for exercising, maintaining a healthy weight and not smoking. Some insurers in my area offer discounts at local health clubs, and corporations also offer incentives to employees who adopt healthy habits. But we really need to go farther.

We know from studies of international populations which lifestyle and eating habits are associated with longevity. But it's hard to change behavior as anyone who's tried to lose weight or quit smoking knows. We need to analyze what motivates people and take advantage of that opportunity. We also need to give people hope and inspiration that it is indeed possible.

That may be the hardest part.

This is the seventh article in a 10-part series, 10 Reasons to Reform Health Care Now:

Part 1: Syrocketing costs are choking American businesses

Part 2: 87 million uninsured, and growing

Part 5: Insurance reimbursements make no sense

Part 6: The malpractice liability crisis persists