CHICAGO — While milk chocolate remains the favorite, a growing number of consumers are sweet on the dark variety, according to research firm Mintel.

Mintel’s latest report revealed that 51% of adults prefer milk chocolate, followed by 35% who favor dark chocolate and 8% who like white chocolate. Comparatively, 2011 research found that 57% chose milk chocolate and 33% preferred dark.

The health benefits of bittersweet may explain a shift to the dark side, said Sarah Day Levesque, food analyst at Mintel.

“The progressively better understood health benefits of dark chocolate may be increasing its popularity as more consumers are looking for indulgent foods that can serve multiple functions such as nutrition or convenience,” Ms. Day Levesque said. “An exception to the pattern of milk chocolate being the consumer favorite is among consumers aged 55-plus who are more likely to favor dark chocolate, most likely because they are seeking added nutritional benefits.”

Forty-six per cent of men age 55 and older and 48% of women over age 55 favor dark chocolate. Nearly three-fourths of all chocolate consumers agree that darker is healthier.