Surprising Reasons You Drink Too Much Wine

(Discovery) - Wine enthusiasts take note: you may be unknowingly serving yourself more than you think.

Exactly how much wine you pour into your glass can vary depending on the size of the wineglass, whether the glass is on the table and even the color of the wine, a new study finds.

In the study, researchers asked participants to pour themselves a "normal" glass of wine under various conditions.

When they were given a wide wineglass, participants poured themselves 12 percent more wine than when they were given a standard wine glass.

This likely happens because people tend to focus more on the vertical measures of liquid than the horizontal, said study researcher Laura Smarandescu, an assistant professor of marketing at Iowa State University.

"That's why people tend to drink less when they drink from a narrow glass," Smarandescu said in a statement.

When using a clear glass, participants poured themselves 9 percent more white wine than red wine, suggesting that the contrast of the wine against the glass also plays a role in determining serving estimates. And participants poured more wine when they were holding the glass compared to when it was resting on the table.

Such differences in wine pouring may mean that someone drinks the equivalent of two or even three servings, when they think they've only had one, the researchers said.