Thirsty shoppers who hop into a convenience store in for a quick, cold drink face an overwhelming assortment of choice. There are dozens of beverage brands to choose from, and they can range in size from mini (8 ounces or so) to mega (24 ounces or more!).
Health-conscious shoppers might take a peek at the calorie label before deciding which beverage to buy, and in what size. These labels were created to help shoppers make informed decisions. But it’s not always clear what the numbers on the label actually mean, especially for younger shoppers.
To test whether teenagers’ purchases would be affected by more direct calorie info, researchers at John Hopkins University in Baltimore, Maryland, staged an experiment. In the soda aisles of six Baltimore convenience stores, the researchers posted signs that put the calorie content of soft drinks into perspective. The signs explained that teens would need to run for 50 minutes or walk five miles to burn off the 250 calories in a 20-ounce soda. After posting the signs, the researchers tracked teens’ purchases for six weeks.
The new information had a big impact on beverage choices. Teens who noticed the signs were more likely to buy a smaller-sized soda with fewer than 250 calories. They were also more likely to choose a less-caloric option (like a fruit drink or water), or to leave the store with no beverage at all! Teens were interviewed after exiting stores, and more than one-third said that they noticed the signs. Among those, 40 percent said that the signs had affected their decision of what to buy.
While the signs were in place (and for a few weeks after), the average number of calories in drinks purchased by teens dropped from 203 to 179. What was the percent decrease in drink calories purchased? Round your answer to the nearest percent.