The key insight here is that small changes in behavior can have large impacts on outcomes. A Health Impact Assessment (pdf) prepared for the city of Los Angeles estimated that if calorie labeling convinced a mere 10 percent of large-chain patrons to order meals that were merely 100 calories lighter, then menu labeling "would avert 38.9% of the 6.75 million pound average annual weight gain in the county population aged 5 years and older." Get 20 percent to reduce their meals by 75 calories? You've knocked out 58.3 percent of the projected 6.75 million pounds. That's huge.
This article available online at:
http://www.theatlantic.com/entertainment/archive/2009/05/ezra-has-a-blog/17750/
