The United States is in the midst of an epidemic of obesity and related health problems, and fast food is bad for you.

Morgan Spurlock's attempt to demonstrate the link between these two matters, using himself as an experimental subject, represents an entertaining, and occasionally horrifying, statement of the obvious.

The larger issue of the relationship between legal consumables and public health turns on the question of responsibility. Does it rest with those of us who eat, drink and inhale the products that clog our arteries and corrode our livers and lungs, or with the companies who sell and advertise them?

Mr. Spurlock's answer, emphatically anticorporate on its surface, is perhaps more ambiguous than it seems.

Texas: not only the largest state in the union but also one of the fattest.

There is a heartbreaking moment when an overweight girl worries that she will never lose weight because she can't afford to eat two sandwiches a day from Subway.