In the past 15 years, smoking has decreased by 20%, but the number of fat Americans has increased by 48%. By 2020, the team calculates that obesity will rob an 18-year-old of 0.7 years of life on average and 0.9 years of "quality of life."
The average gain for an individual from not smoking—0.3 years—is more than offset by the loss of more than a year from weight gain, the authors reported last week in The New England Journal of Medicine. Even if obesity increases level off to as little as 0.15% per year, they'll swamp overall gains from nonsmoking by 2020.
Given the well known and documented power of nicotine as an appetite suppressant, this looks like yet another argument in favor of the public and personal health benefits of smoking. I can see the public service announcement now:
Add an average of .4 years to your life: smoke!