Popeyes and Wendy's aren't too worried about Obamacare's impact on their bottom lines, but the reason for their calm may rest on a faulty assumption.

The two fast food chains expect a significant number of their employees to pay Obamacare's penalty rather than enroll in the company-sponsored plans mandated by the health care law, since the cost of health insurance premiums would be higher.

The 2010 Affordable Care Act will both require all Americans to purchase health insurance, or else pay a penalty, and require all employers with at least 50 full-time employees -- those working at least 30 hours per week -- to offer affordable health insurance to their full-time workers, or else pay penalties.

But Popeyes U.S. President Ralph Bower told the Wall Street Journal that employer-sponsored health insurance is "just not affordable for employees."