"We're killing ourselves," Dr. Kenneth Cooper, known as the father of aerobics and personal physician of President Bush, said.
By the year 2010, more Americans are expected to die from obesity and lack of activity than from tobacco, according to Cooper.
The country is facing "an epidemic of obesity," said Cooper, who has been nominated twice to serve as the country's surgeon general.
Up to 80 percent of disease in the United States today is caused by unhealthy lifestyles, Cooper said.
And children are being affected more than any other segment of the population.
Cooper blamed public schools in part for America's obesity epidemic.
From junk-filled lunches to reduced time spent on physical education, Cooper said America's schools need to "get their head out of the sand" and stop contributing to the obesity problem.
But the problem isn't just at school, Cooper said.
"Kids aren't walking or riding their bikes to school like they used to," he said, adding that the average child in the U.S. spends 40 hours a week either in front of the TV or playing a video game.
Dr. Jui-Lien Chou, medical director of Radiation Oncology Associates in Lubbock.
"I am wholeheartedly agreeable to his approach," Chou said. "Lifestyle changes are the key to a healthy life and longevity."
Cooper is the founder and president of the Cooper Institute and Cooper Aerobics Center in Dallas and is often credited for launching the fitness revolution when he published his book "Aerobics" in 1968.