Increasingly, consumers are placing a priority on health when they go out to eat. And they're looking for a couple of key phrases on the menu to justify their choices.

Sixty four percent of consumers polled in a new study by food consultancy Technomic agree that it is important to eat healthy and pay attention to nutrition, up from 57 percent in 2010. However, the definition of "healthy" has also shifted, with consumers placing more importance on food that is labeled "local," "natural," "organic" and "sustainable." The terms "low-calorie" and "lowfat" still resonate with consumers, but they've been around for a while.

Of the new buzzwords, "sustainable" in particular has entered the spotlight. Since 2011, the number of menu items labeled as sustainable increased by 74 percent in the more than 9,000 restaurants surveyed by Technomic.

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Definitions of sustainability remain fuzzy, as few industries have been able to set measurable perimeters for the term. McDonald's, for instance, promised to use only verified sustainable beef by 2016, but has yet to produce a set of firm criteria for what "sustainable" entails. Customers also remain confused – while the number of sustainable menu items has skyrocketed, only a third of the individuals surveyed said they clearly comprehend the definition of sustainable foods.

Another buzzword experiencing a huge boost in popularity on menus is "gluten-free." Until recently, the term was only seen as a useful descriptor to those who suffer from Celiac disease. However, today gluten-free is one of the top three most popular health descriptors at full service restaurants, along with mainstays "vegetarian" and "organic." From 2010 to 2012, gluten-free options increased from slightly over 100 items to more than 1,000 items on full service menus.

As customers become more health-conscious, restaurants attempt to adjust their offerings. However, as new, trendy classifications take over menus, customers should be sure to look beyond the buzzwords.

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