A new survey from the National Geographic Society and consulting firm GlobeScan shows that humans are eating healthier diets, but not necessarily in a sustainable way.

Since 2008, National Geographic has measured consumption habits and attitudes in 18 countries for what it calls the Greendex survey. The latest survey found that consumers in five growing countries, when told how their habits affect the environment, indicated they would be open to changing their behavior. It also found that people in English-speaking countries and in Sweden were less interested in how their food was produced.

Nicole Darnall, a professor in the School of Sustainability, told National Geographic she wasn't that surprised at the slow adoption rate of sustainability, particularly in the United States.

"We subsidize traditional food production in a way we don't subsidize natural and organic foods," says Darnall. "The developing world is more nimble, less entrenched than we are. It's easier for them to consider alternatives."