Ezra Klein highlights proposed legislation that would require restaurants with more than 20 locations to prominently display the amount of calories, fat, carbs, and other nutritional components of each dish they serve. As Ezra reports, we consistently underestimate the caloric content of the food we eat -- and we underestimate by a lot. For example, "The average respondent underestimated cheese fries with ranch dressing by more than 2,000 calories." (With a 2,000 calorie underestimate, I'm horrified to think what the total must be.) The potential impacts are huge:
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.
And if consumers responded to the nutritional information by changing their preferences, restaurants would respond by changing their menus. People who wanted to make healthier choices would then have healthier options, and the trend would reinforce itself.