Obesity is the No. 1 health threat in the United States today, the head of the leading U.S. federal health agency said on Tuesday. While much of her time is spent preparing to fight anthrax, smallpox, and biological threats, and diseases like SARS and West Nile virus, Centers for Disease, Control and Prevention Director Dr. Julie Gerberding, said Americans are much more likely to die from cancer, heart disease, and diabetes caused by smoking, eating too much and exercising too little. "Unfortunately, poor diet and a lack of exercise have almost caught up with tobacco as being the leading cause of death in the United States," Gerberding told a meeting of the National Health Council, which groups companies and non-profit health advocacy organizations. Reuters