The New York Times > Health > Data on Deaths From Obesity Is Inflated, U.S. Agency Says
They messed up the numbers. Turns out obesity isn't great for you, but it's not in the same league as smoking. Since weight gain is common with smoking cessation this wasn't merely an academic distinction.
In addition to less dangerous than smoking, obesity mortality is concentrated towards the upper end of life, so years-lost are far less than for smoking.