By Cass R. Sunstein WASHINGTON — Almost 70 percent of Americans
have been overweight or obese in recent years, and more than 78
million people in the country have been counted as obese. The
problem has many sources, but one of them is obvious: increased
portion sizes. We have a lot of evidence that people will eat
whatever is put in front of them, even if they aren't hungry. As
portion sizes expand, waistlines expand as well. According to
the Centers for Disease Control and Prevention, the average U.S.
restaurant meal is more than five times larger than it was in
the 1950s. The average hamburger, once less than 4 ounces, is
now more than 12 ounces. The average order of French fries, once
less than 3 ounces, is now more than 6 ounces. There is a clear
correlation between increases in portion sizes and increases in
obesity. That correlation helps explain why obesity has been
more prevalent in the United States than in France. The French
eat high-calorie food, but their portion sizes are smaller. In
supermarkets